phenylephrine-hydrochloride and Influenza--Human

Epidemiological studies support a link between low 25-hydroxyvitamin D levels and a higher risk of viral upper respiratory tract infections. However, whether winter supplementation of vitamin D reduces the risk among children is unknown.. To determine whether high-dose vs standard-dose vitamin D supplementation reduces the incidence of wintertime upper respiratory tract infections in young children.. A randomized clinical trial was conducted during the winter months between September 13, 2011, and June 30, 2015, among children aged 1 through 5 years enrolled in TARGet Kids!, a multisite primary care practice-based research network in Toronto, Ontario, Canada.. Three hundred forty-nine participants were randomized to receive 2000 IU/d of vitamin D oral supplementation (high-dose group) vs 354 participants who were randomized to receive 400 IU/d (standard-dose group) for a minimum of 4 months between September and May.. The primary outcome was the number of laboratory-confirmed viral upper respiratory tract infections based on parent-collected nasal swabs over the winter months. Secondary outcomes included the number of influenza infections, noninfluenza infections, parent-reported upper respiratory tract illnesses, time to first upper respiratory tract infection, and serum 25-hydroxyvitamin D levels at study termination.. Among 703 participants who were randomized (mean age, 2.7 years, 57.7% boys), 699 (99.4%) completed the trial. The mean number of laboratory-confirmed upper respiratory tract infections per child was 1.05 (95% CI, 0.91-1.19) for the high-dose group and 1.03 (95% CI, 0.90-1.16) for the standard-dose group, for a between-group difference of 0.02 (95% CI, -0.17 to 0.21) per child. There was no statistically significant difference in number of laboratory-confirmed infections between groups (incidence rate ratio [RR], 0.97; 95% CI, 0.80-1.16). There was also no significant difference in the median time to the first laboratory-confirmed infection: 3.95 months (95% CI, 3.02-5.95 months) for the high-dose group vs 3.29 months (95% CI, 2.66-4.14 months) for the standard-dose group, or number of parent-reported upper respiratory tract illnesses between groups (625 for high-dose vs 600 for standard-dose groups, incidence RR, 1.01; 95% CI, 0.88-1.16). At study termination, serum 25-hydroxyvitamin D levels were 48.7 ng/mL (95% CI, 46.9-50.5 ng/mL) in the high-dose group and 36.8 ng/mL (95% CI, 35.4-38.2 ng/mL) in the standard-dose group.. Among healthy children aged 1 to 5 years, daily administration of 2000 IU compared with 400 IU of vitamin D supplementation did not reduce overall wintertime upper respiratory tract infections. These findings do not support the routine use of high-dose vitamin D supplementation in children for the prevention of viral upper respiratory tract infections.. clinicaltrials.gov Identifier: NCT01419262.

Topics: Administration, Oral; Child, Preschool; Common Cold; Dietary Supplements; Dose-Response Relationship, Drug; Female; Humans; Incidence; Infant; Influenza, Human; Male; Nose; Respiratory Tract Infections; Virus Diseases; Vitamin D; Vitamins

Anti-pyretic treatment is recommended in the management of influenza infection. In animal models anti-pyretic treatment increases mortality from influenza. We investigated the effects of paracetamol on viral and clinical outcomes in adults with influenza infection.. This is a randomized, double-blind, placebo-controlled trial of adults aged 18-65 years with influenza-like illness and positive influenza rapid antigen test. Treatments were 1 g paracetamol four times a day, or matching placebo, for 5 days. Pernasal swabs were taken for influenza quantitative RT-PCR at Baseline and Days 1, 2 and 5. Temperature and symptom scores were recorded for 5-14 days or time of resolution respectively. The primary outcome variable was area under the curve (AUC) for quantitative PCR log10 viral load from Baseline to Day 5.. A total of 80 participants were randomized: no one was lost to follow up, and one withdrew after 4 days. There were 22 and 24 participants who were influenza PCR-positive in placebo and in paracetamol groups respectively. Mean (SD) AUC PCR log10 viral load was 4.40 (0.91) in placebo and 4.64 (0.88) in paracetamol; difference was -0.24, 95% CI: -0.78 to 0.29, P = 0.36. In all participants there were no differences in symptom scores, temperature, time to resolution of illness and health status, with no interaction between randomized treatment and whether influenza was detected by PCR.. Regular paracetamol had no effect on viral shedding, temperature or clinical symptoms in patients with PCR-confirmed influenza. There remains an insufficient evidence base for paracetamol use in influenza infection.. ACTRN12611000497909 at the Australian New Zealand Clinical Trials Registry.

Topics: Acetaminophen; Adolescent; Adult; Antipyretics; Area Under Curve; Body Temperature; Double-Blind Method; Female; Health Status; Humans; Influenza, Human; Male; Nose; Symptom Assessment; Viral Load; Virus Shedding; Young Adult

Examine differences in the detection of influenza by specimen and test type using paired nasal and nasopharyngeal swabs.. Prospective study. Enrollment took place between January and March 2007 in a central Wisconsin population.. Adult patients were screened and enrolled by trained research coordinators following medical encounters for acute respiratory illnesses of <10 days duration.. Paired nasal and nasopharyngeal swabs were collected from consenting patients and tested by both real-time reverse transcriptase polymerase chain reaction (rRT-PCR) and viral culture. A composite measure of positivity was used as the gold standard; cases included any positive result by rRT-PCR or viral culture from either specimen type.. Paired samples were collected from 240 adults; 33 (14%) individuals tested positive for influenza by rRT-PCR. Using rRT-PCR, the sensitivity of the nasal swab was 89% (95% CI, 78%-99%) and the sensitivity of the nasopharyngeal swab was 94% (95% CI, 87%-100%), compared to a composite gold standard.. Test sensitivity did not vary significantly by swab type when using a highly sensitive molecular diagnostic test, but power was limited to detect modest differences.

Topics: Aged; Aged, 80 and over; Confidence Intervals; Female; Humans; Influenza A virus; Influenza B virus; Influenza, Human; Male; Middle Aged; Nasopharynx; Nose; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Sensitivity and Specificity; Specimen Handling; Virology

Development of influenza vaccines that do not use embryonated eggs as the substrate for vaccine production is a high priority. We conducted this study to determine the protective efficacy a recombinant, baculovirus-expressed seasonal trivalent influenza virus hemagglutinin (rHA0) vaccine (FluBlok(®)).. Healthy adult subjects at 24 centers across the US were randomly assigned to receive a single injection of saline placebo (2304 subjects), or trivalent FluBlok containing 45 mcg of each rHA0 component (2344 subjects). Serum samples for assessment of immune responses by hemagglutination-inhibition (HAI) were taken from a subset of subjects before and 28 days after immunization. Subjects were followed during the 2007-2008 influenza season and combined nasal and throat swabs for virus isolation were obtained from subjects reporting influenza-like illness.. Rates of local and systemic side effects were low, and the rates of systemic side effects were similar in the vaccine and placebo groups. HAI antibody responses were seen in 78%, 81%, and 52% of FluBlok recipients to the H1, H3, and B components, respectively. FluBlok was 44.6% (95% CI, 18.8%, 62.6%) effective in preventing culture-confirmed influenza meeting the CDC influenza-like illness case definition despite significant antigenic mismatch between the vaccine antigens and circulating viruses.. Trivalent rHA0 vaccine was safe, immunogenic and effective in the prevention of culture confirmed influenza illness, including protection against drift variants.

Topics: Adolescent; Adult; Antibodies, Viral; Female; Follow-Up Studies; Hemagglutination Inhibition Tests; Humans; Influenza Vaccines; Influenza, Human; Male; Middle Aged; Nose; Orthomyxoviridae; Pharynx; Placebos; United States; Vaccination; Young Adult

The relationship between seasonal influenza vaccine and susceptibility to 2009 pandemic A/H1N1 virus infection is not fully understood.. One child 6-15 years of age from each of 119 households was randomized to receive 1 dose of inactivated trivalent seasonal influenza vaccine (TIV) or saline placebo in November 2008. Serum samples were collected from study subjects and their household contacts before and 1 month after vaccination (December 2008), after winter (April 2009) and summer influenza (September-October 2009) seasons. Seasonal and pandemic influenza were confirmed by serum hemagglutinination inhibition, viral neutralization titers, and reverse-transcription polymerase chain reaction performed on nasal and throat swab samples collected during illness episodes.. TIV recipients had lower rates of serologically confirmed seasonal A/H1N1 infection (TIV group, 8%; placebo group, 21%; P=.10) and A/H3N2 infection (7% vs 12%; P=A9), but higher rates of pandemic A/H1N1 infection (32% vs 17%; [Formula: see text]). In multivariable analysis, those infected with seasonal influenza A during the study had a lower risk of laboratory-confirmed pandemic A/H1N1 infection (adjusted odds ratio [OR], 0.35; 95% confidence interval [CI], 0.14-0.87), and receipt of seasonal TIV was unassociated with risk of pandemic A/H1N1 infection (adjusted OR, 1.11; 95% CI, 0.54-2.26).. TIV protected against strain-matched infection in children. Seasonal influenza infection appeared to confer cross-protection against pandemic influenza. Whether prior seasonal influenza vaccination affects the risk of infection with the pandemic strain requires additional study.. ClinicalTrials.gov number NCT00792051 .

Topics: Adolescent; Antibodies, Neutralizing; Antibodies, Viral; Child; Cross Protection; Female; Hemagglutination Inhibition Tests; Hong Kong; Humans; Influenza Vaccines; Influenza, Human; Male; Neutralization Tests; Nose; Orthomyxoviridae; Pandemics; Pharynx; Placebos; Reverse Transcriptase Polymerase Chain Reaction; RNA, Viral; Vaccination; Vaccines, Inactivated

Chronically ill older adults constitute a population vulnerable for complications associated with influenza. Study of their immunity to influenza virus may help design better strategies to stimulate protective immune responses.. Immunogenicity of influenza vaccines and immune protection from natural influenza were assessed in older adults with chronic obstructive pulmonary disease as part of a vaccine efficacy trial. Subjects received either trivalent inactivated influenza virus vaccine (TVV) intramuscularly and trivalent live cold-adapted influenza virus vaccine (CAIV-T; n=1107) intranasally (inl) or TVV and placebo inl (P; n=1108).. In the subsets of study subjects assessed, serum hemagglutination inhibition (HAI) and nasal-wash antihemagglutinin (HA) immunoglobulin (Ig) A and IgG antibody levels and anti-influenza virus CD8(+) cytotoxic T lymphocyte activity increased after immunization. Mean postimmunization nasal-wash IgA antibody levels to influenza A H3/HA and B HA were statistically higher in the TVV+CAIV-T group (n=957) than in the TVV+P group (n=951). Postimmunization serum HAI and nasal-wash IgA antibodies to influenza A/H3N2 and B viruses were associated with a reduced relative risk for natural influenza infection.. TVV+CAIV-T appeared more immunogenic than TVV+P, but the observed difference may be clinically unimportant. Anti-influenza serum and nasal-wash antibodies were associated with immune protection.

Topics: Administration, Intranasal; Adult; Aged; Antibodies, Viral; Humans; Influenza A virus; Influenza B virus; Influenza Vaccines; Influenza, Human; Injections, Intramuscular; Nose; Pulmonary Disease, Chronic Obstructive; T-Lymphocytes, Cytotoxic; Treatment Outcome; Vaccination; Vaccines, Combined; Vaccines, Inactivated

Influenza virus is easily spread among the household contacts of an infected person, and prevention of influenza in household contacts can control spread of influenza in the community.. To investigate the efficacy of oseltamivir in preventing spread of influenza to household contacts of influenza-infected index cases (ICs).. Randomized, double-blind, placebo-controlled study conducted at 76 centers in North America and Europe during the winter of 1998-1999.. Three hundred seventy-seven ICs, 163 (43%) of whom had laboratory-confirmed influenza infection, and 955 household contacts (aged >/=12 years) of all ICs (415 contacts of influenza-positive ICs).. Household contacts were randomly assigned by household cluster to take 75 mg of oseltamivir (n = 493) or placebo (n = 462) once daily for 7 days within 48 hours of symptom onset in the IC. The ICs did not receive antiviral treatment.. Clinical influenza in contacts of influenza-positive ICs, confirmed in a laboratory by detection of virus shedding in nose and throat swabs or a 4-fold or greater increase in influenza-specific serum antibody titer between baseline and convalescent serum samples.. In contacts of an influenza-positive IC, the overall protective efficacy of oseltamivir against clinical influenza was 89% for individuals (95% confidence interval [CI], 67%-97%; P<.001) and 84% for households (95% CI, 49%-95%; P<.001). In contacts of all ICs, oseltamivir also significantly reduced incidence of clinical influenza, with 89% protective efficacy (95% CI, 71%-96%; P<.001). Viral shedding was inhibited in contacts taking oseltamivir, with 84% protective efficacy (95% CI, 57%-95%; P<.001). All virus isolates from oseltamivir recipients retained sensitivity to the active metabolite. Oseltamivir was well tolerated; gastrointestinal tract effects were reported with similar frequency in oseltamivir (9.3%) and placebo (7.2%) recipients.. In our sample, postexposure prophylaxis with oseltamivir, 75 mg once daily for 7 days, protected close contacts of influenza-infected persons against influenza illness, prevented outbreaks within households, and was well tolerated.

Topics: Acetamides; Adolescent; Adult; Aged; Antiviral Agents; Double-Blind Method; Enzyme Inhibitors; Family Characteristics; Female; Humans; Influenza, Human; Male; Middle Aged; Neuraminidase; Nose; Orthomyxoviridae; Oseltamivir; Pharynx; Virus Shedding

An investigational live influenza virus vaccine, FluMist, contains three cold-adapted H1N1, H3N2, and B influenza viruses. The vaccine viruses are 6/2 reassortants, in which the hemagglutinin (HA) and neuraminidase (NA) genes are derived from the circulating wild-type viruses and the remaining six genes are derived from the cold-adapted master donor strains. The six genes from the cold-adapted master donor strains ensure the attenuation, and the HA and NA genes from the wild-type viruses confer the ability to induce protective immunity against contemporary influenza strains. The genotypic stability of this vaccine was studied by employing clinical samples collected during an efficacy trial. Viruses present in the nasal and throat swab specimens and in supernatants after culturing the specimens were detected and subtyped by multiplex reverse transcriptase (RT)-PCR. Complete genotypes of these detected viruses were determined by a combination of RT-PCR and restriction fragment length polymorphism, multiplex RT-PCR and fluorescent single-strand conformation polymorphism, and nucleic acid sequencing analysis. The FluMist vaccine appeared to be genotypically stable after replication in the human host. All viruses detected during the 2-week postvaccination period were shed vaccine viruses and had maintained the 6/2 genotype.

Topics: Cold Temperature; Double-Blind Method; Genotype; Humans; Influenza A virus; Influenza B virus; Influenza Vaccines; Influenza, Human; Nose; Pharynx; Polymorphism, Restriction Fragment Length; Polymorphism, Single-Stranded Conformational; Reverse Transcriptase Polymerase Chain Reaction; Sequence Analysis, DNA; Vaccination

Influenza virus neuraminidase is thought to be essential for virus replication in humans; however, to date, available neuraminidase inhibitors are limited to zanamivir, which is topically administered.. To determine the safety, tolerability, and antiviral activity of oral neuraminidase inhibitor oseltamivir (GS4104/Ro64-0796) for prevention and the early treatment of influenza in experimentally infected humans.. Two randomized, double-blind, placebo-controlled trials conducted between June and July 1997.. Individual hotel rooms; 2 large US university medical schools.. A total of 117 healthy adult volunteers (aged 18-40 years; median age, 21 years) who were susceptible (hemagglutination-inhibition antibody titer < or =1:8).. All subjects were inoculated intranasally with influenza A/Texas/36/91 (H1N1) virus. For the prophylaxis study, oral oseltamivir (100 mg once daily [n = 12], 100 mg twice daily [n = 12], or matching placebo [n = 13], starting 26 hours before virus inoculation) was administered. For the treatment study, the same drug was given (20 mg, 100 mg, or 200 mg twice daily, 200 mg once daily, or matching placebo [n = 16], in each group starting 28 hours after inoculation). All regimens were continued for 5 days.. Comparing placebo groups with pooled treatment groups, for prophylaxis, outcomes included frequency of infection and viral shedding; for treatment, viral shedding in titers.. In the prophylaxis study, 8 (67%) of 12 placebo and 8 (38%) of 21 oseltamivir recipients became infected (P = .16; efficacy, 61%); 6 (50%) placebo compared with 0 oseltamivir recipients shed virus (P<.001; efficacy, 100%), and 33% of placebo but no oseltamivir recipient had infection-related respiratory illness (P<.01). Among infected subjects in the treatment study (n = 69), the viral titer area under the curve of the combined oseltamivir groups (n = 56) was lower (median [interquartile range [IQR]], 80 [23-151] vs 273 [79-306] log10 tissue culture-infective doses50 per milliliter x hour; P = .02) than the placebo group (n = 13), and the median (IQR) duration of viral shedding with therapy was reduced from 107 (83-131) to 58 (35-59) hours (P = .003). Oseltamivir treatment also reduced symptom scores (median [IQR] score-hours, 225 [97-349] vs 400 [189-645]; P = .05), and nasal proinflammatory cytokine levels. Transient mild to moderate nausea after dosing was observed in 15 (17%) of 88 oseltamivir and 2 (7%) of 29 placebo recipients (95% confidence interval for difference, -11% to 68%), which was largely prevented by ingestion with food.. In these trials, prophylaxis and early treatment with oral oseltamivir were both associated with significant antiviral and clinical effects in experimental human influenza.

Topics: Administration, Oral; Adolescent; Adult; Amines; Area Under Curve; Dose-Response Relationship, Drug; Double-Blind Method; Enzyme Inhibitors; Female; Humans; Influenza A virus; Influenza, Human; Male; Nausea; Neuraminidase; Nose; Oseltamivir

The sialic acid analogue zanamivir (GG167) is a selective inhibitor of influenza A and B virus neuraminidases. These viral enzymes are essential for the release of virus from infected cells, and they may also reduce the inactivation of virus by respiratory secretions. When administered experimentally directly to the respiratory tract, zanamivir has potent antiviral effects. We assessed the therapeutic activity of zanamivir in adults with acute influenza.. We conducted separate randomized, double-blind studies in 38 centers in North America and 32 centers in Europe during the influenza season of 1994-1995. A total of 417 adults with influenza-like illness of < or =48 hours' duration were randomly assigned to one of three treatments: 6.4 mg of zanamivir by intranasal spray plus 10 mg by inhalation, 10 mg of zanamivir by inhalation plus placebo spray, or placebo by both routes. Treatments were self-administered twice daily for five days.. Of 262 patients with confirmed influenza-virus infection (63 percent of all patients), the median length of time to the alleviation of all major symptoms was one day shorter (four days vs. five days) in the 88 patients given inhaled and intranasal zanamivir (P=0.02) and the 85 patients given inhaled zanamivir alone (P=0.05) than in the 89 patients given placebo. Among the infected patients who were febrile at enrollment and among those who began treatment within 30 hours after the onset of symptoms, the median time to the alleviation of major symptoms was four days in both zanamivir groups and seven days in the placebo group (P< or =0.01). Viral titers of nasal washings in the group given inhaled and intranasal zanamivir were significantly lower than those in the placebo group. The topically administered zanamivir was well tolerated.. In adults with influenza A or B virus infections, direct administration of a selective neuraminidase inhibitor, zanamivir, to the respiratory tract is safe and reduces symptoms if begun early.

Topics: Administration, Inhalation; Administration, Intranasal; Adolescent; Adult; Antiviral Agents; Double-Blind Method; Enzyme Inhibitors; Guanidines; Humans; Influenza A virus; Influenza B virus; Influenza, Human; Neuraminidase; Nose; Pyrans; Sialic Acids; Time Factors; Treatment Outcome; Zanamivir

Purified lymphoblastoid interferon (HuIFN-alpha) or placebo was self-administered intranasally by volunteers using a spray device three times daily for four and one-third days beginning one day before virus challenge. Each subject received a total dose of 35.1 Mu of interferon (IFN) administered in 13 equal doses of 2.7 Mu. Doses were administered in a volume of 0.2 ml (0.1 ml to each nostril). The first group received human rhinoviruses types 9 and 14. There were no significant colds in 19 volunteers receiving IFN and 7 in 23 volunteers receiving placebo (p less than 0.05). Serological responses and/or recovery of challenge virus were obtained in 14 (74%) recipients of IFN and in all 23 recipients of placebo (p less than 0.05). Mean daily and total clinical scores and mean daily and total nasal secretion weights were significantly greater in those receiving placebo than in those given IFN. The second group received influenza virus A/Eng/40/83. There were 4 significant illnesses in 13 volunteers receiving IFN and 10 in 17 volunteers receiving placebo (p greater than 0.05). Serological responses and/or recovery of challenge virus were obtained in 11 volunteers receiving IFN and 14 volunteers receiving placebo. Mean daily secretion weight and mean clinical scores were lower in those given IFN than in those given placebo - the differences were significant for clinical score on 2 days. The results suggest that IFN prophylaxis was less effective against influenza A than against rhinovirus.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adolescent; Adult; Clinical Trials as Topic; Common Cold; Double-Blind Method; Female; Humans; Influenza, Human; Interferon Type I; Male; Middle Aged; Nose; Rhinovirus

We investigated possible associations of HL-A types and antibody-response patterns during clinical trials with a live, attenuated intranasal influenza A vaccine. After vaccination, subjects with HL-A type W16 had, as a group, a mean convalescent-phase hemagglutination-inhibiting antibody titer of 14, which was significantly lower (P less than 0.001) than the mean titer of 36 in subjects without Type W16. Of 25 subjects with a poor antibody response, 32 per cent had HL-A type W16, whereas only 5 per cent with a good response had Type W16. The mean titers in nasal secretions of five W16 subjects at 13 and 30 days were less than 3; in contrast, similar titers of 22 subjects without W16 were 8 and 9 respectively. The results suggest that the lower antibody response in W16 subjects is due to increased cellular resistance to infection rather than to a suppressed immune response because other subjects with W16 had normal antibody responses after vaccination with killed influenza vaccine.

Topics: Antibodies, Viral; Antibody Formation; Clinical Trials as Topic; Convalescence; Hemagglutination Inhibition Tests; Histocompatibility Antigens; HLA Antigens; Humans; Immunity, Cellular; Influenza A virus; Influenza Vaccines; Influenza, Human; Nose; Orthomyxoviridae; Vaccines, Attenuated

Two clinical trials with Alice strain intranasal influenza vaccine were performed. In study no. 1 (utilizing random selection and double-blind control), 50 subjects received a bivalent inactivated influenza vaccine intramuscularly, 99 subjects received Alice strain vaccine intranasally, and 50 subjects received a placebo intranasally. No symptomatology could be attributed to the intranasal route of immunization. Convalescent-phase geometric mean titers of hemagglutination inhibition antibody were higher after intramuscular vaccination; seroconversion occurred in 16 or 17 recipients of the Alice strain, with initial titers of less than 1:8. Clinical and virologic surveillance for 20 weeks after vaccination revealed no influenza A illnesses in participants of the study. In study no. 2, 75% of the subjects with initial nasal antibody titers of less than 1:3 developed measurable nasal antibody after receiving Alice strain vaccine.

Topics: Administration, Intranasal; Adult; Antibodies, Viral; Clinical Trials as Topic; Culture Techniques; Hemagglutination Inhibition Tests; Humans; Immunoglobulin A; Influenza A virus; Influenza Vaccines; Influenza, Human; Injections, Intramuscular; Middle Aged; Nose; Organ Culture Techniques; Placebos; Vaccines, Attenuated

The clinical and antibody responses to Alice strain (AS) live attenuated influenza A (H3N2) vaccine and killed parenteral (KP) bivalent influenza vaccine were compared in a randomly allocated group of 150 elderly volunteers. AS recipients experienced more symptoms but these were mild and short in duration. Rhinitis occurred in 45% and pain at injection site in 25% of the AS and KP groups, respectively. Influenza A (H3N2) serum hemmaglutination inhibition titer responses were significantly higher in KP vaccinees; 95% of KP AND 60% OF AS recipients with initial titers smaller than or equal to 1:16 had fourfold or greater titer rises. KP induced significantly higher nasal neutralization titers but the proportion with fourfold or greater responses was not significantly different. Previous studies have shown poor correlations between antibody levels induced by live influenza vaccines and protection. Natural and/or challenge studies are needed before efficacy of influenza vaccines can be established.

Topics: Aged; Animals; Antibodies, Viral; Cell Line; Hemagglutination Inhibition Tests; Humans; Influenza Vaccines; Influenza, Human; Kidney; Macaca mulatta; Neutralization Tests; Nose; Vaccination; Vaccines, Attenuated

Topics: Age Factors; Amantadine; Amines; Antibody Formation; Antiviral Agents; Body Weight; Clinical Trials as Topic; Cyclooctanes; Cycloparaffins; Humans; Influenza, Human; Male; Nose; Orthomyxoviridae; Placebos; Sputum

Topics: Adult; Animals; Antibody Formation; Antigen-Antibody Reactions; Cell Line; Chick Embryo; Haplorhini; Hemadsorption; Hemagglutination Inhibition Tests; Humans; Immunity, Active; Influenza Vaccines; Influenza, Human; Kidney; Lung; Male; Methods; Mucus; Neuraminidase; Nose; Orthomyxoviridae; Recombination, Genetic; Vaccination; Virus Cultivation

Several factors are associated with the severity of the respiratory disease caused by the influenza virus. Although viral factors are one of the most studied, in recent years the role of the microbiota and co-infections in severe and fatal outcomes has been recognized. However, most of the work has focused on the microbiota of the upper respiratory tract (URT), hindering potential insights from the lower respiratory tract (LRT) that may help to understand the role of the microbiota in Influenza disease. In this work, we characterized the microbiota of the LRT of patients with Influenza A using 16S rRNA sequencing. We tested if patients with different outcomes (deceased/recovered) and use of antibiotics differ in their microbial community composition. We found important differences in the diversity and composition of the microbiota between deceased and recovered patients. In particular, we detected a high abundance of opportunistic pathogens such as Granulicatella, in patients either deceased or with antibiotic treatment. Also, we found antibiotic treatment correlated with lower diversity of microbial communities and with lower probability of survival in Influenza A patients. Altogether, the loss of microbial diversity could generate a disequilibrium in the community, potentially compromising the immune response increasing viral infectivity, promoting the growth of potentially pathogenic bacteria that, together with altered biochemical parameters, can be leading to severe forms of the disease. Overall, the present study gives one of the first characterizations of the diversity and composition of microbial communities in the LRT of Influenza patients and its relationship with clinical variables and disease severity.

Topics: Humans; Influenza, Human; Microbiota; Nose; Respiratory Distress Syndrome; Respiratory System; RNA, Ribosomal, 16S

Reducing zoonotic influenza A virus (IAV) risk in the United States necessitates mitigation of IAV in exhibition swine. We evaluated the effectiveness of shortening swine exhibitions to <72 hours to reduce IAV risk. We longitudinally sampled every pig daily for the full duration of 16 county fairs during 2014-2015 (39,768 nasal wipes from 6,768 pigs). In addition, we estimated IAV prevalence at 195 fairs during 2018-2019 to test the hypothesis that <72-hour swine exhibitions would have lower IAV prevalence. In both studies, we found that shortening duration drastically reduces IAV prevalence in exhibition swine at county fairs. Reduction of viral load in the barn within a county fair is critical to reduce the risk for interspecies IAV transmission and pandemic potential. Therefore, we encourage fair organizers to shorten swine shows to protect the health of both animals and humans.

Topics: Animals; Humans; Influenza A virus; Influenza, Human; Nose; Orthomyxoviridae Infections; Prevalence; Swine; Swine Diseases; United States

Infection with highly pathogenic avian H5N1 influenza virus in humans often leads to severe respiratory disease with high mortality. Experimental infection in non-human primates can provide additional insight into disease pathogenesis. However, such a model should recapitulate the disease symptoms observed in humans, such as pneumonia and inflammatory cytokine response. While previous studies in macaques have demonstrated the occurrence of typical lesions in the lungs early after infection and a high level of immune activation, progression to severe disease and lethality were rarely observed. Here, we evaluated a routinely used combined route of infection via intra-bronchial, oral, and intra-nasal virus inoculation with aerosolized H5N1 exposure, with or without the regular collection of bronchoalveolar lavages early after infection. Both combined route and aerosol exposure resulted in similar levels of virus replication in nose and throat and similar levels of immune activation, cytokine, and chemokine release in the blood. However, while animals exposed to H5N1 by combined-route inoculation developed severe disease with high lethality, aerosolized exposure resulted in less lesions, as measured by consecutive computed tomography and less fever and lethal disease. In conclusion, not virus levels or immune activation, but route of infection determines fatal outcome for highly pathogenic avian H5N1 influenza infection.

Topics: Aerosols; Air Microbiology; Animals; Bronchi; Cytokines; Disease Models, Animal; Environmental Exposure; Humans; Influenza A Virus, H5N1 Subtype; Influenza, Human; Macaca fascicularis; Male; Mouth; Nose

Increased illness due to antigenically drifted A(H3N2) clade 3C.3a influenza viruses prompted concerns about vaccine effectiveness (VE) and vaccine strain selection. We used US virologic surveillance and US Influenza Vaccine Effectiveness (Flu VE) Network data to evaluate consequences of this clade.. Distribution of influenza viruses was described using virologic surveillance data. The Flu VE Network enrolled ambulatory care patients aged ≥6 months with acute respiratory illness at 5 sites. Respiratory specimens were tested for influenza by means of reverse-transcriptase polymerase chain reaction and were sequenced. Using a test-negative design, we estimated VE, comparing the odds of influenza among vaccinated versus unvaccinated participants.. During the 2018-2019 influenza season, A(H3N2) clade 3C.3a viruses caused an increasing proportion of influenza cases. Among 2763 Flu VE Network case patients, 1325 (48%) were infected with A(H1N1)pdm09 and 1350 (49%) with A(H3N2); clade 3C.3a accounted for 977 (93%) of 1054 sequenced A(H3N2) viruses. VE was 44% (95% confidence interval, 37%-51%) against A(H1N1)pdm09 and 9% (-4% to 20%) against A(H3N2); VE was 5% (-10% to 19%) against A(H3N2) clade 3C.3a viruses.. The predominance of A(H3N2) clade 3C.3a viruses during the latter part of the 2018-2019 season was associated with decreased VE, supporting the A(H3N2) vaccine component update for 2019-2020 northern hemisphere influenza vaccines.

Topics: Adolescent; Adult; Aged; Antigenic Variation; Child; Child, Preschool; Female; Humans; Infant; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Influenza Vaccines; Influenza, Human; Male; Middle Aged; Nose; Oropharynx; Population Surveillance; RNA, Viral; United States; Vaccination; Young Adult

Interim results from Canada's Sentinel Practitioner Surveillance Network show that during a season characterised by early co-circulation of influenza A and B viruses, the 2019/20 influenza vaccine has provided substantial protection against medically-attended influenza illness. Adjusted VE overall was 58% (95% confidence interval (CI): 47 to 66): 44% (95% CI: 26 to 58) for A(H1N1)pdm09, 62% (95% CI: 37 to 77) for A(H3N2) and 69% (95% CI: 57 to 77) for influenza B viruses, predominantly B/Victoria lineage.

Topics: Adolescent; Adult; Aged; Antigens, Viral; Canada; Child; Child, Preschool; Female; Genotype; Hemagglutination Inhibition Tests; Humans; Infant; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Influenza B virus; Influenza Vaccines; Influenza, Human; Male; Middle Aged; Molecular Sequence Data; Nasopharynx; Nose; Real-Time Polymerase Chain Reaction; Seasons; Sentinel Surveillance; Sequence Analysis, DNA; Young Adult

Non-human primates form an important animal model for the evaluation of immunogenicity and efficacy of novel 'universal' vaccine candidates against influenza virus. However, in most studies a combination of intra-tracheal or intra-bronchial, oral and nasal virus inoculation is used with a standard virus dose of between 1 and 10 million tissue culture infective doses, which differs from typical modes of virus exposure in humans. This paper studies the systemic and local inflammatory and immune effects of aerosolized versus combined-route exposure to pandemic H1N1 influenza virus. In agreement with a previous study, both combined-route and aerosol exposure resulted in similar levels of virus replication in nose, throat and lung lavages. However, the acute release of pro-inflammatory cytokines and chemokines, acute monocyte activation in peripheral blood as well as increased cytokine production and T-cell proliferation in the lungs were only observed after combined-route infection and not after aerosol exposure. Longitudinal evaluation by computed tomography demonstrated persistence of lung lesions after resolution of the infection and a tendency for more lesions in the lower lung lobes after combined-route exposure versus upper and middle lung lobes after aerosol exposure. Computed tomography scores were observed to correlate with fever. In conclusion, influenza virus infection by aerosol exposure is accompanied by less immune-activation and inflammation in comparison with direct virus installation, despite similar levels of virus replication and development of lesions in the lungs.

Topics: Animals; Bronchi; Bronchoalveolar Lavage Fluid; Cytokines; Disease Models, Animal; Humans; Immunity, Cellular; Immunity, Humoral; Influenza A Virus, H1N1 Subtype; Influenza, Human; Lung; Lymphopenia; Macaca fascicularis; Male; Mouth; Nose; Orthomyxoviridae Infections; Virus Replication; Virus Shedding

Manifestations of infection and the degree of influenza virus vary. We hypothesized that the nose/throat microbiota modifies the duration of influenza symptoms and viral shedding. Exploring these relationships may help identify additional methods for reducing influenza severity and transmission.. Using a household transmission study in Nicaragua, we identified secondary cases of influenza virus infection, defined as contacts with detectable virus or a greater than 4-fold change in hemagglutinin inhibition antibody titer. We characterized the nose/throat microbiota of secondary cases before infection and explored whether the duration of symptoms and shedding differed by bacterial community characteristics.. Among 124 secondary cases of influenza, higher bacterial community diversity before infection was associated with longer shedding duration (Shannon acceleration factor [AF]: 1.61, 95% confidence interval [CI]: 1.24, 2.10) and earlier time to infection (Shannon AF: 0.72, 95% CI: 0.53, 0.97; Chao1 AF: 0.992, 95% CI: 0.986, 0.998). Neisseria and multiple other oligotypes were significantly associated with symptom and shedding durations and time to infection.. The nose/throat microbiota before influenza virus infection was associated with influenza symptoms and shedding durations. Further studies are needed to determine if the nose/throat microbiota is a viable target for reducing influenza symptoms and transmission.

Topics: Adolescent; Adult; Antiviral Agents; Child; Child, Preschool; Family Characteristics; Female; Humans; Infant; Influenza, Human; Male; Microbiota; Nicaragua; Nose; Oseltamivir; Pharynx; Real-Time Polymerase Chain Reaction; Smoking; Virus Shedding; Young Adult

Using a test-negative design, the Canadian Sentinel Practitioner Surveillance Network assessed interim 2018/19 vaccine effectiveness (VE) against predominant influenza A(H1N1)pdm09 viruses. Adjusted VE was 72% (95% confidence interval: 60 to 81) against medically attended, laboratory-confirmed influenza A(H1N1)pdm09 illness. This substantial vaccine protection was observed in all age groups, notably young children who appeared to be disproportionately affected. Sequence analysis identified heterogeneity in emerging clade 6B.1 viruses but no dominant drift variant.

Topics: Adolescent; Adult; Aged; Canada; Case-Control Studies; Child; Child, Preschool; Female; Hemagglutination Inhibition Tests; Humans; Infant; Influenza A Virus, H1N1 Subtype; Influenza Vaccines; Influenza, Human; Male; Middle Aged; Nasopharynx; Nose; Outcome Assessment, Health Care; Real-Time Polymerase Chain Reaction; Seasons; Sensitivity and Specificity; Sentinel Surveillance; Sequence Analysis, DNA; Vaccination; Vaccine Potency

There was a substantial increase with infections of H7N9 avian influenza virus (AIV) in humans during Wave 5 (2016-2017). To investigate whether H7N9 had become more infectious/transmissible and pathogenic overall, we characterized the receptor binding and experimentally infected ferrets with highly pathogenic (HP)- and low pathogenic (LP)-H7N9 isolates selected from Wave 5, and compared their pathogenicity and transmissibility with a Wave 1 isolate from 2013. Studies show that A/Anhui/1/2013 (LP) and A/Chicken/Heyuan/16876/2016 (HP) were highly virulent in ferrets, A/Guangdong/Th008/2017 (HP) and A/Chicken/Huizhou/HZ-3/2017 (HP) had moderate virulence and A/Shenzhen/Th001/2016 (LP) was of low virulence in ferrets. Transmission was observed only in ferrets infected with A/Anhui/1/2013 and A/Chicken/Heyuan/16876/2016, consistent with the idea that sicker ferrets had a higher probability to transmit virus to naive animals. Given the Varied virulence and transmissibility observed in circulating H7N9 viruses from Wave 5, we conclude that the current public health risk of H7N9 has not substantially increased compared to 2013 and the circulating viruses are quite diverse.

Topics: Animals; Ferrets; Genotype; Humans; Influenza A Virus, H7N9 Subtype; Influenza, Human; Nose; Orthomyxoviridae Infections; Pharynx; Receptors, Cell Surface; Viral Proteins; Virulence

Experimental data show that type I interferon has a key role in innate immune response against influenza infection.. We compared nasal levels of interferon-α2 and β among inpatients and outpatients with influenza.. Children younger than 5 years of age with influenza-like illness seeking care at the emergency department within the first 72 h of disease onset were prospectively included. Clinical and demographic data and secretions through nasal wash were obtained. Influenza infection was assessed through reverse-transcription polymerase chain reaction and nasal levels of interferon-α2 and β were measured by enzyme-linked immunosorbent assay. All patients followed until the end of the disease.. One hundred patients were included, of which 24 had confirmed influenza infection, and 5 of them were hospitalized. Subtypes A (H3N2) and B were confirmed in 10 and 14 patients, respectively. Seventy-six patients without influenza, including 48% of outpatients, were recruited as controls. All hospitalized patients were significantly younger regardless of influenza status (age <6 months in 59% vs. 23.2%, p < 0.001). All other data were similar among the groups. Comparing median levels of interferon-α2 among children with influenza, levels were significantly higher in outpatients than in hospitalized patients and were 263.2 pg/mL (25-75 interquartile range: 58.3-634) and detectable in only one patient (90 pg/mL), respectively. The levels of interferon-α2 in controls and those of interferon-β in all groups were not detected.. Higher levels of interferon-α2 in patients with less severe influenza reinforce experimental evidence about the protective role of interferon-α2 against influenza infection.

Topics: Bodily Secretions; Child, Preschool; Cohort Studies; Female; Hospitalization; Humans; Immunity, Innate; Infant; Influenza A Virus, H3N2 Subtype; Influenza, Human; Inpatients; Interferon alpha-2; Interferon Type I; Interferon-beta; Male; Nose; Outpatients; Respiratory Tract Infections

Internet-based participatory surveillance systems, such as the German GrippeWeb, monitor the frequency of acute respiratory illnesses on population level. In order to interpret syndromic information better, we devised a microbiological feasibility study (GrippeWeb-Plus) to test whether self-collection of anterior nasal swabs is operationally possible, acceptable for participants and can yield valid data.. We recruited 103 GrippeWeb participants (73 adults and 30 children) and provided them with a kit, instructions and a questionnaire for each sample. In the first half of 2016, participants took an anterior nasal swab and sent it to the Robert Koch Institute whenever an acute respiratory illness occurred. Reporting of illnesses through the GrippeWeb platform continued as usual. We analysed swabs for the presence of human c-myc-DNA and 22 viral and bacterial pathogens. After the study, we sent participants an evaluation questionnaire. We analysed timeliness, completeness, acceptability and validity.. One hundred and two participants submitted 225 analysable swabs. Ninety per cent of swabs were taken within 3 days of symptom onset. Eighty-nine per cent of swabs had a corresponding reported illness in the GrippeWeb system. Ninety-nine per cent of adults and 96% of children would be willing to participate in a self-swabbing scheme for a longer period. All swabs contained c-myc-DNA. In 119 swabs, we identified any of 14 viruses but no bacteria. The positivity rate of influenza was similar to that in the German physician sentinel.. Self-collection of anterior nasal swabs proofed to be feasible, was well accepted by participants, gave valid results and was an informative adjunct to syndromic data.

Topics: Acute Disease; Adult; Child; Epidemiological Monitoring; Feasibility Studies; Germany; Humans; Influenza, Human; Nose; Respiratory Tract Infections; Specimen Handling; Surveys and Questionnaires; Viruses

Staphylococcus epidermidis is one of the most abundant colonizers of healthy human mucosa including that in the respiratory tract. As the respiratory microbiome has been linked to host immune responses, this study sought to determine the role of nasal mucosa-associated S. epidermidis in innate immune responses against the influenza A virus (IAV). S. epidermidis strains were isolated from nasal mucus samples of healthy individuals. The effects of these mucosa-derived commensal strains on interferon (IFN)-dependent innate immunity and IAV infection dynamics were tested in vitro using normal human nasal epithelial (NHNE) cells and human turbinate mucosa. The effects of S. epidermidis on antiviral immunity were also tested in vivo using an acute IAV infection mouse model.. Exposure of NHNE cells to nasal mucosa-derived S. epidermidis increased IFN-λ mRNA and secreted protein levels in the absence of viral stimulation. In the context of IAV infection, NHNE exposure to S. epidermidis prevented an increase in the viral burden, as revealed by IAV PA mRNA abundance, IAV nucleoprotein levels, and viral titers. S. epidermidis also enhanced transcription of IFN-stimulated genes independently of Toll-like receptor 2 and further induced IFN-λ production in IAV-infected cells by promoting phosphorylation of interferon regulatory factor 7. In a murine infection model, S. epidermidis prevented the spread of IAV to the lungs by stimulating IFN-λ innate immunity and suppressing IAV replication in the nasal mucosa.. The human nasal commensal S. epidermidis mediates front-line antiviral protection against IAV infection through modulation of IFN-λ-dependent innate immune mechanisms in the nasal mucosa, thereby demonstrating the role of host-bacterial commensalism in shaping human antiviral responses.

Topics: Adult; Animals; Cells, Cultured; Host-Pathogen Interactions; Humans; Immunity, Innate; Influenza, Human; Interferons; Male; Mice; Mice, Inbred C57BL; Nasal Mucosa; Nose; Orthomyxoviridae Infections; Staphylococcus epidermidis; Symbiosis

Intranasal inoculation with influenza hemagglutinin subunit with polyinosine-polycytidylic (polyI:C), a synthetic analog for double-stranded RNA, enhances production of vaccine-specific immunoglobulin (Ig) A, which is superior to IgG in prophylactic immunity. The mechanism whereby polyI:C skews to IgA production in the nasal-associated lymph tissue (NALT) was investigated in mouse models. Nasally instilled polyI:C was endocytosed into CD103

Topics: Animals; Antigens, CD; Basic-Leucine Zipper Transcription Factors; Cells, Cultured; Dendritic Cells; Hemagglutinin Glycoproteins, Influenza Virus; Humans; Immunity, Humoral; Immunoglobulin A; Influenza A Virus, H1N1 Subtype; Influenza Vaccines; Influenza, Human; Integrin alpha Chains; Lymphoid Tissue; Mice; Mice, Knockout; Nose; Orthomyxoviridae Infections; Poly I-C; Repressor Proteins; Signal Transduction; Toll-Like Receptor 3; Transforming Growth Factor beta; Vaccination

The characteristics and risk factors of respiratory syncytial virus (RSV) infection among children has not yet been fully understood. To address the characteristics of RSV-associated illness and risk factors of RSV infection among children under 5 years of age in Suzhou, China. From April 2011 to March 2014, we conducted a prospective surveillance among children in Suzhou, China. Nasal or throat swabs were collected from outpatients with influenza-like illness (ILI) and inpatients with severe acute respiratory infections (SARI). RSV was detected by reverse-transcriptase polymerase chain reaction and direct fluorescent antibody assay for children with ILI and SARI, respectively. Multivariable logistic-regression models were constructed to explore risk factors and symptoms of RSV infection. Of 3267 ILI and 1838 SARI children enrolled in the study, 192 (5.9%) and 287 (15.6%) tested positive for RSV, respectively. Among ILI patients, children with RSV infections visited clinics more often (P = 0.005) and had longer duration of fever (P = 0.032) than those without RSV infection. All RSV-positive children had an increased risk of having cough (OR = 2.9), rhinorrhea (OR = 1.6), breathing difficulty (OR = 3.4), wheezing (OR = 3.3), and irritability (OR = 2.7). Children aged <2 years, had history of prematurity (OR = 2.0) and recent respiratory infections (OR = 1.3) were more likely to get infected by RSV. Children with SARI had higher positive rate of RSV than those with ILI. Cough, rhinorrhea, and wheezing were the most common symptoms in RSV infection. Children aged <2 years, had history of prematurity and recent respiratory infections were the potential risk factors for RSV infection.

Topics: Child, Preschool; China; Coinfection; Cough; Epidemiological Monitoring; Female; Fever; Humans; Infant; Influenza, Human; Male; Nose; Orthomyxoviridae; Outpatients; Pharynx; Polymerase Chain Reaction; Prospective Studies; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Respiratory Tract Infections; Risk Factors; Virus Diseases; Viruses

In the 2015-2016 season, quadrivalent live attenuated influenza vaccine (LAIV) and both trivalent and quadrivalent inactivated influenza vaccine (IIV) were available in the United States.. This study, conducted according to a test-negative case-control design, enrolled children aged 2-17 years presenting to outpatient settings with fever and respiratory symptoms for <5 days at 8 sites across the United States between 30 November 2015 and 15 April 2016. A nasal swab was obtained for reverse-transcriptase polymerase chain reaction (RT-PCR) testing for influenza, and influenza vaccination was verified in the medical record or vaccine registry. Influenza vaccine effectiveness (VE) was estimated using a logistic regression model.. Of 1012 children retained for analysis, most children (59%) were unvaccinated, 10% received LAIV, and 31% received IIV. Influenza A (predominantly antigenically similar to the A/California/7/2009 strain) was detected in 14% and influenza B (predominantly a B/Victoria lineage) in 10%. For all influenza, VE was 46% (95% confidence interval [CI], 7%-69%) for LAIV and 65% (48%-76%) for IIV. VE against influenza A(H1N1)pdm09 was 50% (95% CI, -2% to 75%) for LAIV and 71% (51%-82%) for IIV. The odds ratio for vaccine failure with RT-PCR-confirmed A(H1N1)pdm09 was 1.71 (95% CI, 0.78-3.73) in LAIV versus IIV recipients.. LAIV and IIV demonstrated effectiveness against any influenza among children aged 2-17 years in 2015-2016. When compared to all unvaccinated children, VE against influenza A(H1N1)pdm09 was significant for IIV but not LAIV.. NCT01997450.

Topics: Adolescent; Case-Control Studies; Child; Child, Preschool; Female; Humans; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Influenza B virus; Influenza Vaccines; Influenza, Human; Logistic Models; Male; Nose; Seasons; United States; Vaccination; Vaccine Potency; Vaccines, Attenuated; Vaccines, Inactivated

Nasopharyngeal swabs from 148 adult patients with influenza were analyzed by polymerase chain reaction for Staphylococcus aureus and or Streptococcus pneumoniae. We found that patients colonized with S. pneumoniae were younger, had lower oxygen saturations, and were more likely to require admission to critical care.

Topics: Aged; Aged, 80 and over; Coinfection; Female; Humans; Influenza A virus; Influenza, Human; Male; Middle Aged; Nose; Pneumococcal Infections; Staphylococcal Infections; Staphylococcus aureus; Streptococcus pneumoniae

Among 4200 adults who presented with acute respiratory symptoms at a variety of medical practice settings (November 2006 through May 2012), only 13 (0.3%) nasal/throat swabs were positive for influenza C. Influenza C was rarely associated with medical care visits in adults.

Topics: Adolescent; Adult; Aged; Female; Gammainfluenzavirus; Humans; Influenza, Human; Male; Middle Aged; Nose; Pharynx; Respiratory Tract Diseases; Young Adult

Self-collection of nasal swabs could improve the timeliness of influenza virus detection in older adults.. Measure the acceptability, adequacy, timeliness, and validity of self-collected nasal swabs among adults >65 years in Thailand.. Our evaluation consisted of two parts: a one-month study among randomly selected, community-dwelling older adults to simulate community-based surveillance for acute respiratory infections (ARI); and a clinic study of older adults with ARI to evaluate the sensitivity and specificity of self-collected nasal swabs for influenza virus infection compared with healthcare worker (HCW)-collected nasal and nasopharyngeal swabs.. In the community study, 24% of participants experienced an ARI during the observation period. All (100%) participants with an ARI self-collected nasal swabs within 72 hours of symptom onset of which 92% were considered adequate samples. In the clinic study, 45% of patients with ARI presented within 72 hours of symptom onset. The sensitivity of self-collected nasal swabs for detection of influenza virus infection was 78% (95% CI 40-97) compared to nasopharyngeal and 88% (95% CI 47-100) compared to nasal swabs collected by HCWs. Specificity was 100% (95% CI 97-100) compared to both methods. Self-collection of nasal swabs was found acceptable by 99% of participants in both studies.. Self-collection of nasal swabs was acceptable to older adults in Thailand who were able to take adequate samples. Self-collection of nasal swabs may improve the timeliness of sample collection but lower sensitivity will need to be considered.

Topics: Aged; Aged, 80 and over; Female; Humans; Influenza A virus; Influenza, Human; Male; Nasopharynx; Nose; Respiratory Tract Infections; Sensitivity and Specificity; Specimen Handling; Thailand

The influenza A virus components of the live, attenuated influenza vaccine (LAIV) encode the HA and NA gene segments from a circulating virus strain and the remaining gene segments from the cold-adapted master donor virus, A/Ann Arbor/6/1960 (H2N2). The master donor virus imparts at least three phenotypes: temperature-sensitivity (ts), attenuation (att), and cold-adaption (ca). The genetic loci responsible for the att and ts phenotypes of LAIV were mapped to PB1, PB2, and NP by reverse genetics experiments using immortalized cell lines. However, some in vivo studies have demonstrated that the M segment, which acquired an alanine (Ala) to serine (Ser) mutation at M2 position 86 during cold adaption - a mutation found in no other influenza A virus strain - contributes to the att phenotype. Prior studies have shown this region of the M2 cytoplasmic tail to be critical for influenza virus replication. Using reverse genetics, we demonstrate that certain amino acid substitutions at M2 positions 83 and 86 alter the replication of influenza A/Udorn/307/72 (H3N2). Importantly, substitution of a Ser at M2 position 86 reduces A/Udorn/307/72 replication in differentiated primary human nasal epithelial cell (hNECs) cultures, but does not considerably affect replication in MDCK cells. When a Ser was substituted for Ala at M2 86 in LAIV, the virus replicated to higher titers and with faster kinetics in hNEC cultures, implicating this amino acid change as contributing to LAIV attenuation. Increased replication also resulted in increased production of IFN-λ. These data indicate the LAIV associated Ser mutation at M2 position 86 contributes to the att phenotype and is associated with a differential regulation of interferon in LAIV infection.

Topics: Cells, Cultured; DNA Replication; Epithelial Cells; Genetic Loci; Humans; Influenza A virus; Influenza Vaccines; Influenza, Human; Mutation; Nose; Phenotype; Reverse Genetics; Vaccines, Attenuated; Viral Matrix Proteins; Virus Replication

Influenza outbreaks can occur among passengers and crews during the Alaska summertime cruise season. Ill travellers represent a potential source for introduction of novel or antigenically drifted influenza virus strains to the United States. From May to September 2013-2015, the Alaska Division of Public Health, the Centers for Disease Control and Prevention (CDC), and two cruise lines implemented a laboratory-based public health surveillance project to detect influenza and other respiratory viruses among ill crew members and passengers on select cruise ships in Alaska.. Cruise ship medical staff collected 2-3 nasopharyngeal swab specimens per week from passengers and crew members presenting to the ship infirmary with acute respiratory illness (ARI). Specimens were tested for respiratory viruses at the Alaska State Virology Laboratory (ASVL); a subset of specimens positive for influenza virus were sent to CDC for further antigenic characterization.. Of 410 nasopharyngeal specimens, 83% tested positive for at least one respiratory virus; 71% tested positive for influenza A or B virus. Antigenic characterization of pilot project specimens identified strains matching predominant circulating seasonal influenza virus strains, which were included in the northern or southern hemisphere influenza vaccines during those years. Results were relatively consistent across age groups, recent travel history, and influenza vaccination status. Onset dates of illness relative to date of boarding differed between northbound (occurring later in the voyage) and southbound (occurring within the first days of the voyage) cruises.. The high yield of positive results indicated that influenza was common among passengers and crews sampled with ARI. This finding reinforces the need to bolster influenza prevention and control activities on cruise ships. Laboratory-based influenza surveillance on cruise ships may augment inland influenza surveillance and inform control activities. However, these benefits should be weighed against the costs and operational limitations of instituting laboratory-based surveillance programs on ships.

Topics: Adolescent; Adult; Aged; Alaska; Child; Child, Preschool; Disease Outbreaks; Female; Humans; Infant; Influenza A virus; Influenza B virus; Influenza, Human; Male; Middle Aged; Nose; Pilot Projects; Population Surveillance; Ships; Travel; Young Adult

This study was established to provide direct evidence on the incidence of laboratory-confirmed influenza virus and respiratory syncytial virus (RSV) infections in older adults in two cities in Jiangsu Province, China, and the potential impact of acute respiratory infections on frailty.. The cohort was enrolled in Suzhou and Yancheng, two cities in Jiangsu Province in Eastern China. Between November 2015 and March 2016, we enrolled 1532 adults who were 60-89 years of age, and collected blood samples along with baseline data on demographics, general health, chronic diseases, functional status and cognitive function through face-to-face interviews using a standardised questionnaire. Participants are being followed weekly throughout the year to identify acute respiratory illnesses. We schedule home visits to ill participants to collect mid-turbinate nasal and oropharyngeal swabs for laboratory testing and detailed symptom information for the acute illness. Regular follow-up including face-to-face interviews and further blood draws will take place every 6-12 months.. As of 3 September 2016, we had identified 339 qualifying acute respiratory illness events and 1463 (95%) participants remained in the study. Laboratory testing is ongoing.. We plan to conduct laboratory testing to estimate the incidence of influenza virus and RSV infections in older adults. We plan to investigate the impact of these infections on frailty and functional status to determine the association of pre-existing immune status with protection against influenza and RSV infection in unvaccinated older adults, and to assess the exposure to avian influenza viruses in this population.

Topics: Age Factors; Aged; Aged, 80 and over; Aging; Animals; China; Female; Frailty; Humans; Incidence; Influenza, Human; Male; Middle Aged; Nose; Oropharynx; Orthomyxoviridae; Prospective Studies; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Respiratory Tract Infections; Surveys and Questionnaires; Urban Population

Swine farms provide a dynamic environment for the evolution of influenza A viruses (IAVs). The present report shows the results of a surveillance effort of IAV infection in one commercial swine farm in Argentina. Two cross-sectional serological and virological studies (n=480) were carried out in 2011 and 2012. Virus shedding was detected in nasal samples from pigs from ages 7, 21 and 42-days old. More than 90% of sows and gilts but less than 40% of 21-days old piglets had antibodies against IAV. In addition, IAV was detected in 8/17 nasal swabs and 10/15 lung samples taken from necropsied pigs. A subset of these samples was further processed for virus isolation resulting in 6 viruses of the H1N2 subtype (δ2 cluster). Pathological studies revealed an association between suppurative bronchopneumonia and necrotizing bronchiolitis with IAV positive samples. Statistical analyses showed that the degree of lesions in bronchi, bronchiole, and alveoli was higher in lungs positive to IAV. The results of this study depict the relevance of continuing long-term active surveillance of IAV in swine populations to establish IAV evolution relevant to swine and humans.

Topics: Animals; Antibodies, Viral; Argentina; Bronchopneumonia; Cross-Sectional Studies; Epidemiological Monitoring; Humans; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H1N2 Subtype; Influenza, Human; Lung; Nose; Orthomyxoviridae Infections; Sus scrofa; Swine; Swine Diseases; Virus Shedding

The knowledge about the viral etiologies causing respiratory disease in adults is limited. Viral respiratory diseases may lead deterioration in certain patient populations. The aim of this study was to determine the viral etiologies of influenza-like illness among patients requiring hospitalization and to document the risk factors for mortality. This prospective study was performed in one of the 7 centers in Turkey in the context of influenza surveillance by the Global Influenza Hospital Surveillance Network. A 35-bed Adult Emergency Service and 10-bed Acute Care Unit were screened for consequent recruitment of eligible patients daily, on weekdays only. ICD-10 codes in the electronic health records and direct patient encounters were used to screen for the following eligibility diagnoses: acute respiratory tract infection, asthma, heart failure, pneumonia, influenza, chronic obstructive lung disease, dyspnea/respiratory abnormality, respiratory symptoms, cough and fever. A total of 334 patients who were admitted with the eligible ICD-10 codes within the 24th and 48th hours were screened during the study period and of those eligible ones, 106 consented and were swabbed. Nasal or nasopharyngeal swabs were collected using Virocult (Medical Wire & Equipment, UK) and sent to the central laboratory in 1-3 days. Swabs were collected and specimens were introduced to real-time polymerase chain reaction based multiplex kits, as well as, ABI 7500 platform with CDC primers and probes. A total of 106 patients were swabbed. Hospital mortality was 12.2%. More than one fourth of the patients needed a sort of mechanical ventilation support and at least one organ failure developed in one third of the patients. One or more viral pathogens were detected in 56 (52.8%) of the swabbed patients, with influenza H3N2 being the most prevalent one. Having a lower body mass index (OR, 0.845, p= 0.034) was associated with mortality. Chronic lung diseases were shown to confer a survival advantage (OR, 0.127, p= 0.009). Community acquired viral respiratory infections might lead to significant compromise in adult patients. Prevention of malnutrition might result in better outcomes in patients who need acute admission. The survival advantage of those with chronic lung diseases warrants further investigation.

Topics: Adult; Aged; Aged, 80 and over; Female; Hospitalization; Humans; Influenza A Virus, H3N2 Subtype; Influenza, Human; Male; Middle Aged; Nasopharynx; Nose; Prospective Studies; Risk Factors; Turkey; Young Adult

This study reports the results of a systematic screening for respiratory viruses in pediatric outpatients from an emergency department (ED) in southern Brazil during two consecutive influenza seasons. Children eligible for enrollment in this study were aged 24-59 months and presented with acute respiratory symptoms and fever. Naso- and oropharyngeal swabs were collected and multiplex reverse transcription PCR (RT-PCR) was performed to identify the respiratory viruses involved. In total, 492 children were included in this study: 248 in 2010 and 244 in 2011. In 2010, 136 samples (55%) were found to be positive for at least one virus and the most frequently detected viruses were human rhinovirus (HRV) (18%), adenovirus (AdV) (13%), and human coronavirus (CoV) (5%). In 2011, 158 samples (65%) were found to be positive for at least one virus, and the most frequently detected were HRV (29%), AdV (12%), and enterovirus (9%). Further, the presence of asthma (OR, 3.17; 95% CI, 1.86-5.46) was independently associated with HRV infection, whereas fever was associated with AdV (OR, 3.86; 95% CI, 1.31-16.52) and influenza infections (OR, 3.74; 95% CI, 1.26-16.06). Ten patients (2%) were diagnosed with pneumonia, and six of these tested positive for viral infection (4 HRV, 1 RSV, and 1 AdV). Thus, this study identified the most common respiratory viruses found in preschool children in the study region and demonstrated their high frequency, highlighting the need for improved data collection, and case management in order to stimulate preventive measures against these infections. J. Med. Virol. 88:1325-1333, 2016. © 2016 Wiley Periodicals, Inc.

Topics: Adenoviridae; Adenoviridae Infections; Brazil; Child; Child, Preschool; Female; Humans; Infant; Influenza A virus; Influenza, Human; Male; Multiplex Polymerase Chain Reaction; Nose; Oropharynx; Outpatients; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Respiratory Tract Infections; Rhinovirus; Seasons; Virus Diseases; Viruses

Respiratory viruses are a cause of upper respiratory tract infections (URTI), but can be associated with severe lower respiratory tract infections (LRTI) in immunocompromised patients. The objective of this study was to investigate the genetic variability of influenza virus, parainfluenza virus and respiratory syncytial virus (RSV) and the duration of viral shedding in hematological patients. Nasopharyngeal swabs from hematological patients were screened for influenza, parainfluenza and RSV on admission as well as on development of respiratory symptoms. Consecutive swabs were collected until viral clearance. Out of 672 tested patients, a total of 111 patients (17%) were infected with one of the investigated viral agents: 40 with influenza, 13 with parainfluenza and 64 with RSV; six patients had influenza/RSV or parainfluenza/RSV co-infections. The majority of infected patients (n = 75/111) underwent stem cell transplantation (42 autologous, 48 allogeneic, 15 autologous and allogeneic). LRTI was observed in 48 patients, of whom 15 patients developed severe LRTI, and 13 patients with respiratory tract infection died. Phylogenetic analysis revealed a variety of influenza A(H1N1)pdm09, A(H3N2), influenza B, parainfluenza 3 and RSV A, B viruses. RSV A was detected in 54 patients, RSV B in ten patients. The newly emerging RSV A genotype ON1 predominated in the study cohort and was found in 48 (75%) of 64 RSV-infected patients. Furthermore, two distinct clusters were detected for RSV A genotype ON1, identical RSV G gene sequences in these patients are consistent with nosocomial transmission. Long-term viral shedding for more than 30 days was significantly associated with prior allogeneic transplantation (p = 0.01) and was most pronounced in patients with RSV infection (n = 16) with a median duration of viral shedding for 80 days (range 35-334 days). Long-term shedding of respiratory viruses might be a catalyzer of nosocomial transmission and must be considered for efficient infection control in immunocompromised patients.

Topics: Adult; Aged; Aged, 80 and over; Cohort Studies; Communicable Disease Control; Cross Infection; Female; Genotype; Hematologic Diseases; Humans; Influenza, Human; Male; Middle Aged; Mutation; Nose; Orthomyxoviridae; Parainfluenza Virus 3, Human; Paramyxoviridae Infections; Phylogeny; Polymerase Chain Reaction; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Retrospective Studies; Sequence Analysis, DNA; Time Factors; Transplantation, Homologous; Virus Shedding; Young Adult

The 2009 H1N1 pandemic emphasized a need to evaluate zoonotic transmission of influenza A in swine production. Airborne influenza A virus has been detected in swine facilities during an outbreak. However, the personal exposure of veterinarians treating infected swine has not been characterized. Two personal bioaerosol samplers, the NIOSH bioaerosol sampler and the personal high-flow inhalable sampler head (PHISH), were placed in the breathing zone of veterinarians treating swine infected with either H1N1 or H3N2 influenza A. A greater number of viral particles were recovered from the NIOSH bioaerosol sampler (2094 RNA copies/m3) compared to the PHISH sampler (545 RNA copies/m3). In addition, the majority of viral particles were detected by the NIOSH bioaerosol sampler in the >4 μm size fraction. These results suggest that airborne influenza A virus is present in the breathing zone of veterinarians treating swine, and the aerosol route of zoonotic transmission of influenza virus should be further evaluated among agricultural workers.

Topics: Aerosols; Agriculture; Air Microbiology; Animals; Environmental Monitoring; Humans; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Influenza, Human; Mouth; Nose; Occupational Exposure; Orthomyxoviridae Infections; Real-Time Polymerase Chain Reaction; Respiration; RNA, Viral; Swine; Swine Diseases; Veterinarians

The Influenza virus is a leading cause of respiratory disease in the United States each year. While the virus normally causes mild to moderate disease, hospitalization and death can occur in many cases. There are several methodologies that are used for detection; however problems such as decreased sensitivity and high rates of false-negative results may arise. There is a crucial need for an effective sample preparation technology that concentrates viruses at low abundance while excluding resident analytes that may interfere with detection. Nanotrap particles are hydrogel particles that are coupled to chemical dye affinity baits that bind a broad range of proteins and virions. Within minutes (<30 minutes), Nanotrap particles concentrate low abundant proteins and viruses from clinically complex matrices. Nanotrap particles with reactive red baits concentrated numerous respiratory viruses including various strains and subtypes of Influenza virus, Coronavirus, and Respiratory Syncytial Virus from saliva, nasal fluid swab specimens, and nasal aspirates. Detection was enhanced more than 10-fold when coupled to plaque assays and qRT-PCR. Importantly, Nanotrap particle can efficiently capture and concentrate multiple viral pathogens during a coinfection scenario. These results collectively demonstrate that Nanotrap particles are an important tool that can easily be integrated into various detection methodologies.

Topics: Coinfection; Coronavirus; Coronavirus Infections; Humans; Influenza, Human; Nanotechnology; Nose; Orthomyxoviridae; Respiratory Syncytial Viruses; Respiratory Tract Infections; Saliva

Influenza A viruses are a major health threat to livestock and humans, causing considerable mortality, morbidity, and economic loss. Current inactivated influenza vaccines are strain specific and new vaccines need to be produced at frequent intervals to combat newly arising influenza virus strains, so that a universal vaccine is highly desirable. We show that pandemic H1N1 influenza virus in which the hemagglutinin signal sequence has been suppressed (S-FLU), when administered to pigs by aerosol can induce CD4 and CD8 T cell immune responses in blood, bronchoalveolar lavage (BAL), and tracheobronchial lymph nodes. Neutralizing Ab was not produced. Detection of a BAL response correlated with a reduction in viral titer in nasal swabs and lungs, following challenge with H1N1 pandemic virus. Intratracheal immunization with a higher dose of a heterologous H5N1 S-FLU vaccine induced weaker BAL and stronger tracheobronchial lymph node responses and a lesser reduction in viral titer. We conclude that local cellular immune responses are important for protection against influenza A virus infection, that these can be most efficiently induced by aerosol immunization targeting the lower respiratory tract, and that S-FLU is a promising universal influenza vaccine candidate.

Topics: Aerosols; Animals; Antibodies, Neutralizing; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Hemagglutinin Glycoproteins, Influenza Virus; Humans; Immunity, Cellular; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H5N1 Subtype; Influenza Vaccines; Influenza, Human; Interferon-gamma; Lung; Nose; Orthomyxoviridae Infections; Pandemics; Sus scrofa; Vaccination; Vaccines, Inactivated; Viral Load

There are few estimates of effectiveness influenza vaccine in preventing serious outcomes due to influenza in older adults.. Adults aged ≥50 years who sought medical care for acute respiratory illness were enrolled. A nose/throat swab was tested for influenza virus by reverse transcription-polymerase chain reaction. Clinical and demographic data were collected, including verification of receipt of trivalent inactivated influenza vaccination (IIV-3). Adjusted odds ratios were estimated by multivariable logistic regression models with an L1 penalty on all covariates except vaccination status.. A total of 1047 subjects were enrolled from November through April during 5 influenza seasons during 2006-2012, excluding the 2009-2010 season. Of those enrolled, 927 (88%) had complete influenza virus testing, vaccination status, and demographic data obtained. Of 86 (9.3%) influenza virus-positive patients, 47 (55%) were vaccinated. Of 841 influenza virus-negative patients, 646 (76.8%) were vaccinated. Over 5 influenza seasons, IIV-3 was 58.4% effective (95% confidence interval [CI], 37.0%-75.6%) for the prevention of medically attended laboratory-confirmed influenza illness in adults aged ≥50 years and 58.4% effective (95% CI, 7.9%-81.1%) in adults aged ≥65 years.. Influenza vaccine was moderately effective in preventing influenza-associated medical care visits in older adults.

Topics: Aged; Case-Control Studies; Female; Hospitalization; Humans; Influenza Vaccines; Influenza, Human; Logistic Models; Male; Middle Aged; Multivariate Analysis; Nose; Orthomyxoviridae; Pharynx; Prospective Studies; Seasons; Vaccination; Vaccines, Inactivated

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antigens, Viral; Canada; Case-Control Studies; Child; Child, Preschool; Female; Hemagglutination Inhibition Tests; Humans; Infant; Influenza A Virus, H3N2 Subtype; Influenza Vaccines; Influenza, Human; Male; Middle Aged; Molecular Sequence Data; Nasopharynx; Nose; Outcome Assessment, Health Care; Physicians, Family; Polymerase Chain Reaction; Sentinel Surveillance; Sequence Analysis, DNA; Vaccination

Influenza virus infections are responsible for significant morbidity and mortality in both pediatric and adult populations worldwide. Rapid and accurate diagnosis of influenza is necessary for appropriate patient management during the influenza season and for optimal utilization of anti-influenza therapy. We prospectively tested the accuracy of a simple and rapid diagnostic method.. Ninety-eight samples (nasal and pharyngeal swabs) from patients with upper respiratory tract infection symptoms who presented to primary healthcare centres in Barcelona (Spain) were prospectively analyzed. The samples were collected as part of influenza surveillance program. Samples that had enough volume to make the new test after aliquoting the amount needed to perform routine tests were included. None of the samples were pre-selected as a result of their status in relation to influenza virus. Samples were analyzed by in-house real-time PCR and Alere i Influenza A & B (Alere i), which uses isothermal amplification of nucleic acids for the qualitative detection of influenza A and B in nasal swabs transported in viral transport media. The two techniques were compared by positive percent agreement (PPA) and negative percent agreement (NPA). Statistical analysis was performed with Stata.. Of the 98 samples analysed 90 were concordant; 46 (46.9%) were positive and 44 (44.9%) were negative. Five samples showed invalid results with the Alere i test and could be not re-tested due to insufficient sample volume and were not included in the final statistical analysis. In the 93 remaining samples, the Alere i test showed 97% of accuracy having correctly classified 90 samples. We obtained discordant results in 3 samples (3%). The PPA was 93.8% for influenza A and 94.1% for influenza B, and NPA was 100% for influenza A and influenza B virus. In addition, the Alere i was very rapid (15 minutes or less) and extremely easy to use.. The Alere i test provided a good correlation compared to the real-time PCR test for the diagnosis of influenza. Since this method can be performed in minutes, it allows immediate, accurate clinical decisions to prescribe appropriate antiviral treatment or isolation of patients.

Topics: Adult; Child; Humans; Influenza A virus; Influenza B virus; Influenza, Human; Nose; Nucleic Acid Amplification Techniques; Pharynx; Real-Time Polymerase Chain Reaction; RNA, Viral; Sensitivity and Specificity; Spain; Time Factors

We evaluated the feasibility of asking pregnant women to self-collect and ship respiratory specimens.. In a preliminary laboratory study, we compared the RT-PCR cycle threshold (CT) values of influenza A and B viruses incubated at 4 storage temperatures (from 4 to 35°C) for 6 time periods (8, 24, 48, 72, and 168 hours and 30 days), resulting in 24 conditions that were compared to an aliquot tested after standard freezing (-20°C) (baseline condition). In a subsequent pilot study, during January-February, 2014, we delivered respiratory specimen collection kits to 53 pregnant women with a medically attended acute respiratory illness using three delivery methods.. CT values were stable after storage at temperatures <27°C for up to 72 hours for influenza A viruses and 48 hours for influenza B viruses. Of 53 women who received kits during the pilot, 89% collected and shipped nasal swabs as requested. However, 30% (14/47) of the women took over 2 days to collect and ship their specimen. The human control gene, ribonuclease P (RNase P), was detected in 100% of nasal swab specimens. However, the mean CT values for RNase P (26.5, 95% confidence interval [CI] = 26.0-27.1) and for the 8 influenza A virus positives in our pilot (32.2, 95% CI = 28.9-35.5) were significantly higher than the CTs observed in our 2010-2012 study using staff-collected nasal pharyngeal swabs (P-values < 0.01).. Self-collection of respiratory specimens is a promising research method, but further research is needed to quantify the sensitivity and specificity of the approach.

Topics: Adult; Female; Humans; Influenza A virus; Influenza B virus; Influenza, Human; Nose; Pilot Projects; Polymerase Chain Reaction; Pregnancy; Pregnancy Complications, Infectious; Ribonuclease P; Sensitivity and Specificity; Specimen Handling; Turbinates

Viral shedding is often considered to correlate with the infectivity of influenza, but the evidence for this is limited.. In a detailed study of influenza virus transmission within households in 2008-2012, index case patients with confirmed influenza were identified in outpatient clinics, and we collected nose and throat swab specimens for testing by reverse-transcription polymerase chain reaction from all household members regardless of illness. We used individual-based hazard models to characterize the relationship between viral load (V) and infectivity.. Assuming that infectivity was proportional to viral load V gave the worst fit, because it strongly overestimated the proportion of transmission occurring at symptom onset. Alternative models assuming that infectivity was proportional to a various functions of V provided better fits, although they all overestimated the proportion of transmission occurring >3 days after symptom onset. The best fitting model assumed that infectivity was proportion to V(γ), with estimates of γ = 0.136 and γ = 0.156 for seasonal influenza A(H1N1) and A(H3N2) respectively.. All the models we considered that used viral loads to approximate infectivity of a case imperfectly explained the timing of influenza secondary infections in households. Identification of more accurate correlates of infectivity will be important to inform control policies and disease modeling.

Topics: Adolescent; Adult; Family Characteristics; Female; Humans; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Influenza, Human; Linear Models; Male; Middle Aged; Nose; Oseltamivir; Pharynx; Prospective Studies; Specimen Handling; Viral Load; Virus Shedding; Young Adult

The 2014/15 influenza season in Canada was characterized by an early epidemic due to vaccine-mismatched influenza A(H3N2) viruses, disproportionately affecting elderly individuals ≥65-years-old. We assessed vaccine effectiveness (VE) against A(H3N2) hospitalization among elderly individuals during the peak weeks of the 2014/15 epidemic in Quebec, Canada.. Nasal specimens and clinical/epidemiological data were collected within 7 days of illness onset from elderly patients admitted with respiratory symptoms to one of four participating hospitals between November 30, 2014 and January 13, 2015. Cases tested RT-PCR positive for influenza A(H3N2) and controls tested negative for any influenza. VE was assessed by test-negative case-control design.. There were 314 participants including 186 cases (62% vaccinated) and 128 controls (59% vaccinated) included in primary VE analysis. Median age was 81.5 years, two-thirds were admitted from the community and 91% had underlying comorbidity. Crude VE against A(H3N2) hospitalization was -17% (95%CI: -86% to 26%), decreasing to -23% (95%CI: -99 to 23%) with adjustment for age and comorbidity, and to -39% (95%CI: -142 to 20%) with additional adjustment for specimen collection interval, calendar time, type of residence and hospital. In sensitivity analyses, VE estimates were improved toward the null with restriction to participants admitted from the community (-2%; 95%CI: -105 to 49%) or with specimen collection ≤4 days since illness onset (- 8%; 95%CI: -104 to 43%) but further from the null with restriction to participants with comorbidity (-51%; 95%CI: -169 to 15%).. The 2014/15 mismatched influenza vaccine provided elderly patients with no cross-protection against hospitalization with the A(H3N2) epidemic strain, reinforcing the need for adjunct protective measures among high-risk individuals and improved vaccine options.

Topics: Aged; Aged, 80 and over; Female; Hospitalization; Humans; Influenza A Virus, H3N2 Subtype; Influenza Vaccines; Influenza, Human; Male; Nose; Quebec; Sentinel Surveillance

Nasal and throat swab samples were collected from 400 subjects with influenza-like illness during June to September, 2012 from two heavily crowded slums, Rayerbazar and Hazaribagh, situated southeast of Dhaka, Bangladesh. Forty-one samples were positive for influenza B virus using quantitative RT-PCR, but no influenza A virus was detected. Antigenic characterization revealed that the influenza B viruses were of Yamagata and Victoria lineages, which was confirmed from genetic analysis of hemagglutinin (HA) and neuraminidase (NA) genes. Co-circulation of influenza B viruses of both Yamagata and Victoria lineages in the slums of Dhaka indicates that introduction of a tetravalent vaccine formulation that includes both of these influenza B virus lineages would be more effective in this population.

Topics: Antigens, Viral; Bangladesh; Child, Preschool; Female; Hemagglutinin Glycoproteins, Influenza Virus; Humans; Influenza B virus; Influenza, Human; Male; Neuraminidase; Nose; Pharynx; Poverty Areas; Reverse Transcriptase Polymerase Chain Reaction; RNA, Viral

Influenza viruses are global pathogens that infect approximately 10-20% of the world's population each year. Vaccines, including the live attenuated influenza vaccine (LAIV), are the best defense against influenza infections. The LAIV is a novel vaccine that actively replicates in the human nasal epithelium and elicits both mucosal and systemic protective immune responses. The differences in replication and innate immune responses following infection of human nasal epithelium with influenza seasonal wild type (WT) and LAIV viruses remain unknown. Using a model of primary differentiated human nasal epithelial cell (hNECs) cultures, we compared influenza WT and antigenically-matched cold adapted (CA) LAIV virus replication and the subsequent innate immune response including host cellular pattern recognition protein expression, host innate immune gene expression, secreted pro-inflammatory cytokine production, and intracellular viral RNA levels. Growth curves comparing virus replication between WT and LAIV strains revealed significantly less infectious virus production during LAIV compared with WT infection. Despite this disparity in infectious virus production the LAIV strains elicited a more robust innate immune response with increased expression of RIG-I, TLR-3, IFNβ, STAT-1, IRF-7, MxA, and IP-10. There were no differences in cytotoxicity between hNEC cultures infected with WT and LAIV strains as measured by basolateral levels of LDH. Elevated levels of intracellular viral RNA during LAIV as compared with WT virus infection of hNEC cultures at 33°C may explain the augmented innate immune response via the up-regulation of pattern recognition receptors and down-stream type I IFN expression. Taken together our results suggest that the decreased replication of LAIV strains in human nasal epithelial cells is associated with a robust innate immune response that differs from infection with seasonal influenza viruses, limits LAIV shedding and plays a role in the silent clinical phenotype seen in human LAIV inoculation.

Topics: Cells, Cultured; Chemokines; Epithelial Cells; Humans; Immunity, Innate; Influenza Vaccines; Influenza, Human; Nose; Orthomyxoviridae; RNA, Viral; Vaccines, Attenuated; Virus Replication

The 2013/14 influenza season to date in Canada has been characterised by predominant (90%) A(H1N1)pdm09 activity. Vaccine effectiveness (VE) was assessed in January 2014 by Canada's sentinel surveillance network using a test-negative case-control design. Interim adjusted-VE against medically-attended laboratory-confirmed influenza A(H1N1)pdm09 infection was 74% (95% CI: 58-83). Relative to vaccine, A(H1N1)pdm09 viruses were antigenically similar and genetically well conserved, with most showing just three mutations across the 50 amino acids comprising antigenic sites of the haemagglutinin protein.

Topics: Adolescent; Adult; Aged; Canada; Case-Control Studies; Child; Child, Preschool; Female; Hemagglutination Inhibition Tests; Humans; Infant; Influenza A Virus, H1N1 Subtype; Influenza Vaccines; Influenza, Human; Nasopharynx; Nose; Outcome Assessment, Health Care; Real-Time Polymerase Chain Reaction; Seasons; Sensitivity and Specificity; Sentinel Surveillance; Sequence Analysis, DNA; Vaccination

We investigated the protective efficacy of two intranasal chitosan (CSN and TM-CSN) adjuvanted H5N1 Influenza vaccines against highly pathogenic avian Influenza (HPAI) intratracheal and intranasal challenge in a ferret model. Six groups of 6 ferrets were intranasally vaccinated twice, 21 days apart, with either placebo, antigen alone, CSN adjuvanted antigen, or TM-CSN adjuvanted antigen. Homologous and intra-subtypic antibody cross-reacting responses were assessed. Ferrets were inoculated intratracheally (all treatments) or intranasally (CSN adjuvanted and placebo treatments only) with clade 1 HPAI A/Vietnam/1194/2004 (H5N1) virus 28 days after the second vaccination and subsequently monitored for morbidity and mortality outcomes. Clinical signs were assessed and nasal as well as throat swabs were taken daily for virology. Samples of lung tissue, nasal turbinates, brain, and olfactory bulb were analysed for the presence of virus and examined for histolopathological findings. In contrast to animals vaccinated with antigen alone, the CSN and TM-CSN adjuvanted vaccines induced high levels of antibodies, protected ferrets from death, reduced viral replication and abrogated disease after intratracheal challenge, and in the case of CSN after intranasal challenge. In particular, the TM-CSN adjuvanted vaccine was highly effective at eliciting protective immunity from intratracheal challenge; serologically, protective titres were demonstrable after one vaccination. The 2-dose schedule with TM-CSN vaccine also induced cross-reactive antibodies to clade 2.1 and 2.2 H5N1 viruses. Furthermore ferrets immunised with TM-CSN had no detectable virus in the respiratory tract or brain, whereas there were signs of virus in the throat and lungs, albeit at significantly reduced levels, in CSN vaccinated animals. This study demonstrated for the first time that CSN and in particular TM-CSN adjuvanted intranasal vaccines have the potential to protect against significant mortality and morbidity arising from infection with HPAI H5N1 virus.

Topics: Adjuvants, Immunologic; Administration, Intranasal; Animals; Animals, Outbred Strains; Antibodies, Neutralizing; Antibodies, Viral; Chitosan; Dogs; Ferrets; Humans; Influenza A Virus, H5N1 Subtype; Influenza Vaccines; Influenza, Human; Madin Darby Canine Kidney Cells; Male; Nose; Trachea; Vaccination; Vaccine Potency; Viral Load

Topics: Aerosols; Air Movements; Air Pressure; Catheterization; Humans; Infectious Disease Transmission, Patient-to-Professional; Influenza, Human; Masks; Nebulizers and Vaporizers; Noninvasive Ventilation; Nose; Occupational Exposure; Personnel, Hospital; Risk Assessment; Ventilation

A limitation to efficient lentivirus-mediated airway gene transfer is the lack of receptors to commonly used viral envelopes on the luminal surface of airway epithelia. The use of viral envelopes with natural tropism to the airway could be useful for overcoming this limitation.. We investigated influenza hemagglutinin (HA) pseudotyped equine infectious anemia virus-derived lentiviral vector-mediated gene transfer to the airway epithelium of adult and newborn mice. For these studies, high-titer vectors were delivered by intranasal administration. In addition, we tested the feasibility of vector re-dosing to the nasal airway.. Delivery of high-titer HA pseudotyped lentiviral vectors by nasal administration to newborn mouse pups or adult mice results in the efficient transduction of airway epithelial cells in the nose, trachea, and lungs. In the nose, vector expression was predominant in the respiratory epithelium and was not observed in the olfactory epithelium. In the trachea and large airways of the lung, approximately 46% and 40%, respectively, of surface epithelial cells could be transduced. The efficiency of re-dosing to the nasal airway of mice was found to be dependent of the age of the animal when the first dose is administered, as well as the length of time between doses.. A single intranasal dose of concentrated influenza HA-pseudotyped lentiviral vector is sufficient for efficient gene transfer to the airways of mice. This is a promising result that could lead to the development of effective gene transfer reagents for the treatment of cystic fibrosis and other human lung diseases.

Topics: Administration, Intranasal; Animals; Epithelial Cells; Feasibility Studies; Gene Expression Regulation; Genetic Vectors; HEK293 Cells; Hemagglutinin Glycoproteins, Influenza Virus; Humans; Infectious Anemia Virus, Equine; Influenza, Human; Lac Operon; Lung; Mice; Mice, Inbred Strains; Nose; Respiratory Mucosa; Respiratory System; Trachea; Transduction, Genetic; Viral Tropism

The 2012/13 influenza season in Canada has been characterised to date by early and moderately severe activity, dominated (90%) by the A(H3N2) subtype. Vaccine effectiveness (VE) was assessed in January 2013 by Canada's sentinel surveillance network using a test-negative case-control design. Interim adjusted-VE against medically attended laboratory-confirmed influenza A(H3N2) infection was 45% (95% CI: 13-66). Influenza A(H3N2) viruses in Canada are similar to the vaccine, based on haemagglutination inhibition; however, antigenic site mutations are described in the haemagglutinin gene.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antigens, Viral; Canada; Case-Control Studies; Child; Child, Preschool; Female; Hemagglutination Inhibition Tests; Humans; Influenza A Virus, H3N2 Subtype; Influenza Vaccines; Influenza, Human; Male; Middle Aged; Nasopharynx; Nose; Physicians, Family; Polymerase Chain Reaction; Sentinel Surveillance; Sequence Analysis, DNA; Treatment Outcome

Within the Influenza Monitoring Vaccine Effectiveness in Europe (I-MOVE) project we conducted a multicentre case–control study in eight European Union (EU) Member States to estimate the 2011/12 influenza vaccine effectiveness against medically attended influenza-like illness (ILI) laboratory-confirmed as influenza A(H3) among the vaccination target groups. Practitioners systematically selected ILI / acute respiratory infection patients to swab within seven days of symptom onset. We restricted the study population to those meeting the EU ILI case definition and compared influenza A(H3) positive to influenza laboratory-negative patients. We used logistic regression with study site as fixed effect and calculated adjusted influenza vaccine effectiveness (IVE), controlling for potential confounders (age group, sex, month of symptom onset, chronic diseases and related hospitalisations, number of practitioner visits in the previous year). Adjusted IVE was 25% (95% confidence intervals (CI): -6 to 47) among all ages (n=1,014), 63% (95% CI: 26 to 82) in adults aged between 15 and 59 years and 15% (95% CI: -33 to 46) among those aged 60 years and above. Adjusted IVE was 38% (95%CI: -8 to 65) in the early influenza season (up to week 6 of 2012) and -1% (95% CI: -60 to 37) in the late phase. The results suggested a low adjusted IVE in 2011/12. The lower IVE in the late season could be due to virus changes through the season or waning immunity. Virological surveillance should be enhanced to quantify change over time and understand its relation with duration of immunological protection. Seasonal influenza vaccines should be improved to achieve acceptable levels of protection.

Topics: Adolescent; Adult; Aged; Case-Control Studies; Child; Child, Preschool; Confidence Intervals; Europe; Female; Hospitalization; Humans; Infant; Infant, Newborn; Influenza A Virus, H3N2 Subtype; Influenza A Virus, H3N8 Subtype; Influenza Vaccines; Influenza, Human; Logistic Models; Male; Middle Aged; Nasopharynx; Nose; Reverse Transcriptase Polymerase Chain Reaction; Seasons; Sentinel Surveillance; Treatment Outcome; Vaccination; Young Adult

Few studies have investigated the validity of self-collected nose and throat swabs for influenza confirmation in community settings. We followed outpatients with confirmed influenza with sequential measurement of viral loads and applied log-linear regression models to the viral shedding patterns. Among 176 outpatients with confirmed influenza, the detection of virus and quantitative viral loads obtained from self-swabs was consistent with statistical predictions based on earlier and later measurements, suggesting that self-collected nose and throat swabs can be a valid alternative for virologic confirmation of influenza A or B infection in a community setting.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Clinical Laboratory Techniques; Female; Humans; Infant; Infant, Newborn; Influenza, Human; Male; Middle Aged; Nose; Orthomyxoviridae; Outpatients; Pharynx; Self-Examination; Specimen Handling; Viral Load; Virus Shedding; Young Adult

Influenza A virus encodes for eleven proteins, of which HA, NA, NS1 and PB1-F2 have been implicated in viral pathogenicity and virulence. Thus, in addition to the HA and NA gene segments, monitoring diversity of NS1 and PB1-F2 is also important.. 55 out of 166 circulating influenza A strains (31 H1N1 and 24 H3N2) were randomly picked during 2007-2009 and NS and PB1-F2 genes were sequenced. Phylogenetic analysis was carried out with reference to the prototype strains, concurrent vaccine strains and other reference strains isolated world wide.. Comparative analysis of both nucleotide and deduced amino acid sequences, revealed presence of NS gene with A/PR/8/34(H1N1)-like mutations (H4N, Q21R, A22V, K44R, N53D, C59R, V60A, F103S and M106I) in both RNA-binding and effector domain of NS1 protein, and G63E, the HPAI-H5N1-like mutation in NEP/NS2 of five A/H1N1 strains of 2007 and 2009. NS1 of other A/H1N1 strains clustered with concurrent A/H1N1 vaccine strains. Of 31 A/H1N1 strains, five had PB1-F2 similar to the H3N2 strains; six had non-functional PB1-F2 protein (11 amino acids) similar to the 2009 pandemic H1N1 strains and rest 20 strains had 57 amino acids PB1-F2 protein, similar to concurrent A/H1N1 vaccine strain. Interestingly, three A/H1N1 strains with H3N2-like PB1-F2 protein carried primitive PR8-like NS gene. Full gene sequencing of PB1 gene confirmed presence of H3N2-like PB1 gene in these A/H1N1 strains.. Overall the study highlights reassortment event involving gene segments other than HA and NA in the co-circulating A/H1N1 and A/H3N2 strains and their importance in complexity of influenza virus genetics. In contrast, NS and PB1-F2 genes of all A/H3N2 eastern India strains were highly conserved and homologous to the concurrent A/H3N2 vaccine strains suggesting that these gene segments of H3N2 viruses are evolutionarily more stable compared to H1N1 viruses.

Topics: Amino Acid Sequence; Base Sequence; Cluster Analysis; Humans; India; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Influenza, Human; Molecular Sequence Data; Nose; Pharynx; Phylogeny; Reassortant Viruses; RNA, Viral; Sequence Analysis, DNA; Viral Nonstructural Proteins; Viral Proteins

Influenza infections may result in different clinical presentations. This study aims to determine the clinical differences between circulating influenza strains in a young healthy adult population in the tropics.. A febrile respiratory illness (FRI) (fever ≥ 37.5°C with cough and/or sore throat) surveillance program was started in 4 large military camps in Singapore on May 2009. Personnel with FRI who visited the camp clinics from 11 May 2009 to 25 June 2010 were recruited. Nasal washes and interviewer-administered questionnaires on demographic information and clinical features were obtained from consenting participants. All personnel who tested positive for influenza were included in the study. Overall symptom load was quantified by counting the symptoms or signs, and differences between strains evaluated using linear models.. There were 434 (52.9%) pandemic H1N1-2009, 58 (7.1%) seasonal H3N2, 269 (32.8%) influenza B, and 10 (1.2%) seasonal H1N1 cases. Few seasonal influenza A (H1N1) infections were detected and were therefore excluded from analyses, together with undetermined influenza subtypes (44 (1.5%)), or more than 1 co-infecting subtype (6 (0.2%)). Pandemic H1N1-2009 cases had significantly fewer symptoms or signs (mean 7.2, 95%CI 6.9-7.4, difference 1.6, 95%CI 1.2-2.0, p < 0.001) than the other two subtypes (mean 8.7, 95%CI 8.5-9.0). There were no statistical differences between H3N2 and influenza B (p = 0.58). Those with nasal congestion, rash, eye symptoms, injected pharynx or fever were more likely to have H3N2; and those with sore throat, fever, injected pharynx or rhinorrhoea were more likely to have influenza B than H1N1-2009.. Influenza cases have different clinical presentations in the young adult population. Pandemic H1N1 influenza cases had fewer and milder clinical symptoms than seasonal influenza. As we only included febrile cases and had no information on the proportion of afebrile infections, further research is needed to confirm whether the relatively milder presentation of pandemic versus seasonal influenza infections applies to all infections or only febrile illnesses.

Topics: Female; Fever; Humans; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Influenza, Human; Male; Military Personnel; Nose; Pharyngitis; Singapore; Surveys and Questionnaires; Tropical Climate; Young Adult

In acute-care hospitals, no evidence of a protective effect of healthcare worker (HCW) vaccination on hospital-acquired influenza (HAI) in patients has been documented. Our study objective was to ascertain the effectiveness of influenza vaccination of HCW on HAI among patients.. A nested case-control investigation was implemented in a prospective surveillance study of influenza-like illness (ILI) in a tertiary acute-care university hospital. Cases were patients with virologically-confirmed influenza occurring ≥ 72 h after admission, and controls were patients with ILI presenting during hospitalisation with negative influenza results after nasal swab testing. Four controls per case, matched per influenza season (2004-05, 2005-06 and 2006-07), were randomly selected. Univariate and multivariate conditional logistic regression models were fitted to assess factors associated with HAI among patients.. In total, among 55 patients analysed, 11 (20%) had laboratory-confirmed HAI. The median HCW vaccination rate in the units was 36%. The median proportion of vaccinated HCW in these units was 11.5% for cases vs. 36.1% for the controls (P = 0.11); 2 (20%) cases and 21 (48%) controls were vaccinated against influenza in the current season (P = 0.16). The proportion of ≥ 35% vaccinated HCW in short-stay units appeared to protect against HAI among patients (odds ratio = 0.07; 95% confidence interval 0.005-0.98), independently of patient age, influenza season and potential influenza source in the units.. Our observational study indicates a shielding effect of more than 35% of vaccinated HCW on HAI among patients in acute-care units. Investigations, such as controlled clinical trials, are needed to validate the benefits of HCW vaccination on HAI incidence in patients.

Topics: Adult; Aged; Aged, 80 and over; Case-Control Studies; Cross Infection; Female; Health Personnel; Hemagglutination Inhibition Tests; Hospitals; Humans; Influenza Vaccines; Influenza, Human; Male; Middle Aged; Nose; Orthomyxoviridae; Prospective Studies; Vaccination

To estimate influenza vaccine effectiveness (VE) for the 2007-2008 season and assess the sentinel surveillance system in Canada for monitoring virus evolution and impact on VE.. Nasal/nasopharyngeal swabs and epidemiologic details were collected from patients presenting to a sentinel physician within 7 days of influenza-like illness onset. Cases tested positive for influenza A/B virus by real-time polymerase chain reaction; controls tested negative. Hemagglutination inhibition (HI) and gene sequencing explored virus relatedness to vaccine. VE was calculated as 1 minus the odds ratio for influenza in vaccinated versus nonvaccinated participants, with adjustment for confounders.. Of 1425 participants, 21% were vaccinated. Influenza virus was detected in 689 (48%), of which isolates from 663 were typed/subtyped: 189 (29%) were A/H1, 210 (32%) were A/H3, and 264 (40%) were B. Of A/H1N1 isolates, 6% showed minor HI antigenic mismatch to vaccine, with greater variation based on genetic identity. All A/H3N2 isolates showed moderate antigenic mismatch, and 98% of influenza B virus isolates showed major lineage-level mismatch to vaccine. Adjusted VE for A/H1N1, A/H3N2, and B components was 69% (95% confidence interval [CI], 44%-83%), 57% (95% CI, 32%-73%), and 55% (95% CI, 32%-70%), respectively, with an overall VE of 60% (95% CI, 45%-71%).. Detailed antigenic and genotypic analysis of influenza viruses was consistent with epidemiologic estimates of VE showing cross-protection. A routine sentinel surveillance system that combines detailed virus and VE monitoring annually, as modeled in Canada, may guide improved vaccine selection and protection.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antigens, Viral; Canada; Child; Child, Preschool; Cluster Analysis; Cross Protection; Female; Genotype; Hemagglutination Inhibition Tests; Humans; Infant; Influenza A virus; Influenza B virus; Influenza Vaccines; Influenza, Human; Male; Middle Aged; Molecular Sequence Data; Nasopharynx; Nose; Real-Time Polymerase Chain Reaction; Sentinel Surveillance; Sequence Analysis, DNA; Young Adult

In March 2009, a new strain of influenza A/H1N1 virus was identified in Mexico, responsible for a pandemic. Worldwide, more than 13,500 patients died, most often from acute respiratory distress syndrome. Because sudden death cases were rare, involving mostly young apparently healthy persons, influenza A/H1N1 (2009)-related deaths may be misdiagnosed, which can raise medico-legal issues.. we report on an unexpected out-of-hospital death involving a young male with no past medical history and no vaccination. Fever was his only symptom. Laboratory tests: histology showed patchy necrotic foci with mononuclear inflammation in the lungs. The heart was histologically normal, but virological analyses using molecular biology on frozen myocardial samples showed high virus load. In conclusion, this case report shows that influenza A/H1N1 (2009) virus can be a cause of sudden cardiac death in the young and demonstrates the importance of quantitative virological analyses for the diagnosis of myocarditis.

Topics: Death, Sudden; DNA, Viral; Heart; Humans; Inflammation; Influenza A Virus, H1N1 Subtype; Influenza, Human; Lung; Male; Myocardium; Necrosis; Nose; Real-Time Polymerase Chain Reaction; Viral Load; Young Adult

Many viruses are known to cause influenza-like illness (ILI); however, in nearly 50% of patients, the etiologic agent remains unknown. The distribution of viruses in patients with ILI was investigated during the 2009 A/H1N1 influenza pandemic (A/H1N1p). From June 2009 to January 2010, 660 patients with suspected influenza were questioned and examined, and nasal swabs were collected. All patient samples were tested for influenza virus, and 286 negative nasal swabs were tested further for 18 other respiratory viruses using real-time RT-PCR. Two waves of ILI were observed in the epidemic curve (weeks 35-42 and 42-49). At least eight viruses co-circulated during this period: human rhinovirus (HRV) (58), parainfluenza 1-4 viruses (PIV) (9), human Coronavirus (hCoV) OC43 (9), enterovirus (5), adenovirus (AdV) (4), and human metapneumovirus (hMPV) (2); however, 204 samples remained negative for all viruses tested. ILI symptoms, according to the Centers for Disease Control and Prevention criteria for ILI definition, were reported in 75% of cases. These patients had positive swabs for A/H1N1p, HRV, hCoV-OC43, PIV, AdV, and hMPV without significant difference with non-ILI patients. This study found that many respiratory viruses circulated during this period and that the A/H1N1p did not impact on the kinetics of other respiratory viruses. The proportion of non-documented cases remains high. ILI could not distinguish A/H1N1p infection from that due to other respiratory viruses. However, in multivariate anlaysis, cough, chills, hyperemia, and dyspnea were associated significantly with influenza virus versus other respiratory viruses.

Topics: Adolescent; Adult; Aged; Child; Female; Humans; Influenza, Human; Male; Middle Aged; Nose; Prevalence; Real-Time Polymerase Chain Reaction; Respiratory Tract Diseases; Reverse Transcriptase Polymerase Chain Reaction; RNA Viruses; Young Adult

We performed a case-control study to estimate vaccine effectiveness (VE) for prevention of hospitalization due to pandemic influenza A(H1N1)pdm09 (pH1N1) and to identify risk factors for pH1N1 and acute respiratory infection (ARI) in 10 hospitals in Berlin from December 2009 to April 2010.. Cases were patients aged 18-65 years with onset of ARI ≤10 days before admission testing positive for pH1N1 by PCR performed on nasal and throat swabs or by serological testing. Cases were compared to (1) matched hospital controls with acute surgical, traumatological or other diagnoses matched on age, sex and vaccination probability, and (2) ARI patients testing negative for pH1N1. Additionally, ARI cases were compared to matched hospital controls. A standardized interview and chart review elicited demographic and clinical data as well as potential risk factors for pH1N1/ARI. VE was estimated by 1-(Odds ratio) for pH1N1-vaccination ≥10 days before symptom onset using exact logistic regression analysis.. Of 177 ARI cases recruited, 27 tested pH1N1 positive. A monovalent AS03-adjuvanted pH1N1 vaccine was the only pandemic vaccine type identified among cases and controls (vaccination coverage in control group 1 and 2: 15% and 5.9%). The only breakthrough infections were observed in 2 of 3 vaccinated HIV positive pH1N1 patients. After exclusion of HIV positive participants, VE was 96% (95%CI: 26-100%) in the matched multivariate analysis and 46% (95%CI: -376-100%) in the test-negative analysis. Exposure to children in the household was independently associated with hospitalization for pH1N1 and ARI.. Though limited by low vaccination coverage and number of pH1N1 cases, our results suggest a protective effect of the AS03-adjuvanted pH1N1 vaccine for the prevention of pH1N1 hospitalization. The use of hospital but not test-negative controls showed a statistically protective effect of pH1N1-vaccination and permitted the integrated assessment of risk factors for pH1N1-infection. To increase statistical power and to permit stratified analyses (e.g. VE for specific risk groups), the authors suggest pooling of future studies assessing effectiveness of influenza vaccines for prevention of severe disease from different centres.

Topics: Adolescent; Adult; Aged; Berlin; Case-Control Studies; Female; Hospitalization; Humans; Influenza A Virus, H1N1 Subtype; Influenza Vaccines; Influenza, Human; Male; Middle Aged; Nose; Pharynx; Polymerase Chain Reaction; Pregnancy; Prospective Studies; Risk Factors; Serologic Tests; Vaccination; Young Adult

Real-time polymerase chain reaction (PCR) can be considered the gold standard for detection of influenza viruses due to its high sensitivity and specificity. Roche has developed the RealTime ready Influenza A/H1N1 Detection Set, consisting of a generic influenza virus A PCR targeting the M2 gene (M2 PCR) and a specific PCR targeting the hemagglutinin (HA) of A/H1N1-pdm09 (HA PCR, 2009 H1N1), with the intention to make a reliable, rapid, and simple test to detect and quantify 2009 H1N1 in clinical samples. We evaluated this kit against the US Centers for Disease Control and Prevention (USCDC)/World Health Organization real-time PCR for influenza virus using 419 nose and throat swabs from 210 patients collected in 3 large hospitals in Ho Chi Minh City, Vietnam. In the per-patient analysis, when compared to CDC PCR, the sensitivity and specificity of the M2 PCR were 85.8% and 97.6%, respectively; the sensitivity and specificity of HA PCR were 88.2% and 100%, respectively. In the per-sample analysis, the sensitivity and specificity in nose swabs were higher than those in throat swabs for both M2 and HA PCRs. The viral loads as determined with the M2 and HA PCRs correlated well with the Ct values of the CDC PCR. Compared with the CDC PCR, the kit has a reasonable sensitivity and very good specificity for the detection and quantification of influenza A virus and A/H1N1-pdm09. However, given the current status of 2009 H1N1, a kit that can detect all circulating seasonal influenza viruses would be preferable.

Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Female; Hospitals; Humans; Infant; Influenza A Virus, H1N1 Subtype; Influenza, Human; Male; Middle Aged; Molecular Diagnostic Techniques; Nose; Pharynx; Real-Time Polymerase Chain Reaction; Sensitivity and Specificity; Vietnam; Virology; Young Adult

Rapid antigen tests are commonly used by clinicians for rapid, simple, point-of-care testing. Five rapid antigen tests were shown to have low sensitivity (40.3-58.8%) when compared to real-time RT-PCR using nasal wash specimens from patients with influenza-like-illness (N = 167) that were collected previously and confirmed as 2009 pandemic influenza A (H1N1)-positive by PCR. Rapid antigen test sensitivity correlated with virus levels in nasal secretions when comparisons were made to cycle threshold (C(T)) values obtained from real-time RT-PCR. When C(T) values are <25 (equating to viral concentrations of >10(4)  TCID(50)/ml) sensitivity for all five rapid antigen kits was high (range: 83-94% positive); however, when C(T) values are >30 (10(2)  TCID(50)/ml), sensitivities of only 16-18% were observed for four of five rapid antigen kits. The Directigen EZ Flu A + B test detected more positive samples (35%) at lower viral concentrations with C(T) values >30 when compared with other commercial kits (P = 0.05). Rapid antigen test results must be interpreted with caution, and negative specimens may need confirmation by sensitive molecular assays.

Topics: Antigens, Viral; Bodily Secretions; Clinical Laboratory Techniques; Humans; Immunoassay; Influenza A Virus, H1N1 Subtype; Influenza, Human; Nose; Point-of-Care Systems; Sensitivity and Specificity; Viral Load

Topics: Aged; Aged, 80 and over; Diagnosis, Differential; Female; Humans; Influenza A Virus, H1N1 Subtype; Influenza, Human; Intensive Care Units; Male; Middle Aged; Nasopharynx; Nose; Pharynx; Reverse Transcriptase Polymerase Chain Reaction; Sensitivity and Specificity; Trachea; Viral Load; Young Adult

Current evidence supporting the effectiveness of influenza vaccine in preventing hospitalizations in older adults is insufficient.. During 3 influenza seasons, 2006-2009, community-dwelling adults aged ≥50 y hospitalized with respiratory symptoms were prospectively enrolled in this study. We tested nose and throat samples for influenza virus by reverse transcriptase-polymerase chain reaction. We estimated vaccine effectiveness by comparing vaccination status between influenza-positive cases and influenza-negative controls using logistic regression models with propensity score adjustment.. Overall, 450 (59%) of 763 eligible patients were enrolled; 417 (93%) of enrolled patients had adequate respiratory samples, had known influenza vaccination status, and were community-dwelling. The proportions of influenza-positive patients were 8%, 20%, and 6% in the 3 successive seasons. Of 39 influenza-positive participants, 14 (36%) were vaccinated compared with 250 (66%) of 378 influenza-negative controls. Propensity score-adjusted vaccine effectiveness for the 3 seasons combined was 61.2% (95% confidence interval, 17.5%-81.8%).. Overall, in this moderately well-vaccinated population of older adults, laboratory-confirmed influenza virus accounted for 9.3% (95% confidence interval, 6.6%-12.1%) of all respiratory hospitalizations during 3 influenza seasons, and influenza vaccination prevented 61.2% of such hospitalizations.

Topics: Aged; Aged, 80 and over; Female; Hospitalization; Humans; Influenza Vaccines; Influenza, Human; Male; Middle Aged; Nose; Orthomyxoviridae; Pharynx; Prevalence; Prospective Studies; Reverse Transcriptase Polymerase Chain Reaction; RNA, Viral; Vaccination; Virology

We identified febrile pediatric outpatients seeking care for influenza like illness in Bangkok. Two nasal and 1 throat swab were tested using the QuickVue A+B rapid influenza kit and reverse transcription-polymerase chain reaction. Among 142 pandemic influenza A (H1N1)-positive patients, the QuickVue test identified 89 positive tests for a sensitivity of 62.7% (95% confidence interval [CI]: 54.7-70.6). Specificity was 99.2% (95% CI: 98-100). In the 0 to 2 years age group, sensitivity was 76.7% (95% CI: 61.5-91.8). Throat and nasal swabs are equally useful diagnostic specimens for reverse transcription-polymerase chain reaction diagnosis.

Topics: Adolescent; Antigens, Viral; Child; Child, Preschool; Disease Outbreaks; Humans; Immunoassay; Infant; Infant, Newborn; Influenza A virus; Influenza A Virus, H1N1 Subtype; Influenza B virus; Influenza, Human; Nose; Pharynx; Reagent Kits, Diagnostic; Reverse Transcriptase Polymerase Chain Reaction; RNA, Viral; Sensitivity and Specificity; Specimen Handling; Thailand; Time Factors

Rapid antigen testing of upper respiratory secretions collected with various swab types is often utilized for laboratory diagnoses of influenza virus infection. There are limited data on the effects of swab composition on test performance. This study compared the performance of the Quidel QuickVue Influenza A+B test on secretions from the anterior nares when a polyurethane foam swab was used for collection to that when a nylon flocked swab was used for collection. One hundred subjects who presented to a pediatric emergency department with symptoms suggestive of an influenza virus infection were recruited for the study. Foam and flocked swabs of the anterior nares were obtained from separate nares of each subject before a posterior nasopharyngeal swab was collected and placed into viral transport medium. The QuickVue test was performed directly on each swab type, and the results were compared to the results of reverse transcription-PCR (RT-PCR), direct fluorescent antibody (DFA) test, and viral culture performed on the transport medium. RT-PCR alone and DFA combined with culture were utilized as separate gold standards. There were 56 cases of influenza detected by RT-PCR; the QuickVue test was positive for 40 foam and 30 flocked swabs, for sensitivities of 71% and 54%, respectively (P = 0.01). Similarly, there were 49 influenza cases detected by DFA and/or culture; the QuickVue test was positive for 38 foam and 30 flocked swabs, for sensitivities of 78% and 61%, respectively (P = 0.13). This study suggests that polyurethane foam swabs perform better than nylon flocked swabs for the collection of secretions from anterior nares in the Quidel QuickVue Influenza A+B test.

Topics: Adolescent; Antigens, Viral; Bodily Secretions; Child; Clinical Laboratory Techniques; Emergency Medical Services; Humans; Influenza, Human; Nasopharynx; Nose; Nylons; Orthomyxoviridae; Polyurethanes; Sensitivity and Specificity; Specimen Handling

Large clinical trials have demonstrated the therapeutic efficacy of oseltamivir against influenza. We assessed the indirect effectiveness of oseltamivir in reducing secondary household transmission in an incident cohort of influenza index patients and their household members.. We recruited index outpatients whose rapid test results were positive for influenza from February through September 2007 and January through September 2008. Household contacts were followed up for 7-10 days during 3-4 home visits to monitor symptoms. Nose and throat swabs were collected and tested for influenza by reverse-transcription polymerase chain reaction or viral culture.. We followed up 384 index patients and their household contacts. Index patients who took oseltamivir within 24 h of symptom onset halved the time to symptom alleviation (adjusted acceleration factor, 0.56; 95% confidence interval [CI], 0.42-0.76). Oseltamivir treatment was not associated with statistically significant reduction in the duration of viral shedding. Household contacts of index patients who had taken oseltamivir within 24 h of onset had a nonstatistically significant lower risk of developing laboratory-confirmed infection (adjusted odds ratio, 0.54; 95% CI, 0.11-2.57) and a marginally statistically significant lower risk of clinical illness (adjusted odds ratio, 0.52; 95% CI, 0.25-1.08) compared with contacts of index patients who did not take oseltamivir.. Oseltamivir treatment is effective in reducing the duration of symptoms, but evidence of household reduction in transmission of influenza virus was inconclusive.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antiviral Agents; Child; Child, Preschool; Family Characteristics; Family Health; Humans; Infant; Influenza, Human; Male; Middle Aged; Nose; Orthomyxoviridae; Oseltamivir; Pharynx; Reverse Transcriptase Polymerase Chain Reaction; Time Factors; Treatment Outcome; Virus Shedding; Young Adult

Swine-origin influenza A H1N1 (S-OIV) has not been systematically studied in Indian children.. To study the clinical characteristics, morbidity and mortality pattern in children with S-OIV infection.. This prospective study was conducted during the 'containment phase' of the pandemic in New Delhi from 10 June to 5 August 2009. All children suspected of being infected by S-OIV were admitted to the isolation wards and clinically evaluated according to WHO guidelines. Nasal and throat swabs were collected immediately for real-time reverse transcriptase polymerase chain reaction (RT-PCR). Haemoglobin, total leucocyte and platelet counts and chest radiography were undertaken in all patients. Those who tested positive for S-OIV infection were treated with oseltamivir for 5 days in isolation wards.. Thirty-seven children fulfilled the inclusion criteria. Twenty-one tested positive for S-OIV by RT-PCR and 16 tested negative. Comparison of the clinical characteristics of the two groups showed that duration of cough was longer in children with S-OIV (p<0.03). Total leucocyte and lymphocyte counts were significantly less in the S-OIV group (p<0.001 and , 0.02, respectively). Oseltamivir-related gastritis was seen in 38% of children. All improved and were discharged.. S-OIV infection in Indian children had features similar to those of seasonal influenza. Lymphopenia is an important feature of S-OIV.

Topics: Animals; Child; Child, Preschool; Female; Gastritis; Humans; India; Infant; Influenza A Virus, H1N1 Subtype; Influenza, Human; Leukocyte Count; Lymphopenia; Male; Nose; Oseltamivir; Pharynx; Radiography, Thoracic; Retrospective Studies; Reverse Transcriptase Polymerase Chain Reaction; RNA, Viral

While influenza surveillance has increased in most developing countries in the last few years, little influenza surveillance has been carried out in sub-Saharan Africa and no information is available in Central Africa. The objective of this study was to assess the prevalence of influenza viruses circulating in Yaounde, Cameroon and determine their antigenic and genetic characteristics.. Throat and/or nasal swabs were collected from November 2007 to October 2008 from outpatients with influenza-like illness (ILI) in Yaounde, Cameroon and analyzed by two different techniques: a one-step real time reverse transcription-polymerase chain reaction (RT-PCR) and virus isolation in MDCK cells. Typing and subtyping of virus isolates was performed by hemagglutination inhibition (HI), and viruses were sent to the WHO Collaborating Centre in London, UK for further characterization and analyses of antiviral resistance by enzyme inhibition assay and nucleotide sequencing.. A total of 238 patients with ILI were sampled. During this period 70 (29%) samples were positive for influenza by RT-PCR, of which only 26 (11%) were positive by virus isolation. By HI assay, 20 of the 26 isolates were influenza type A (10 H3N2 and 10 H1N1) and 6 were influenza type B (2 B/Victoria/2/87 lineage and 4 B/Yagamata/16/88 lineage). Seven (70%) of the H1N1 isolates were shown to be resistant to oseltamivir due to a H275Y mutation.. This study confirmed the circulation of influenza A(H1N1), A(H3N2) and B viruses in the human population in Central Africa and describes the emergence of oseltamivir-resistant A(H1N1) viruses in Central Africa.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Amino Acid Substitution; Animals; Antiviral Agents; Cameroon; Cell Line; Child; Child, Preschool; Dogs; Drug Resistance, Viral; Female; Hemagglutination Inhibition Tests; Humans; Infant; Influenza, Human; Male; Middle Aged; Nose; Orthomyxoviridae; Oseltamivir; Pharynx; Prevalence; Reverse Transcriptase Polymerase Chain Reaction; RNA, Viral; Young Adult

A pandemic influenza A/H1N1v strain with the neuraminidase H274Y mutation was detected in nasal secretions of a 2-year-old leukemic patient with influenza-like illness after 18 days of treatment with oseltamivir. At baseline, no drug-resistant virus was found, while 4 days after treatment initiation a mixture of wild-type and mutated virus was detected. After treatment interruption, the wild type influenza virus re-emerged and became prevalent in nasal secretions after a few days, suggesting the lower fitness of the mutated virus strain. The patient slowly improved concurrently with a decrease in virus load, which resulted negative 42 days after diagnosis. No other drug-resistant influenza A/H1N1v virus strains have been detected in Italy (up to the end of November 2009) since the first case of the novel A/H1N1v virus was identified in the country (May 2009).

Topics: Amino Acid Substitution; Antiviral Agents; Bodily Secretions; Child, Preschool; Drug Resistance, Viral; Female; Humans; Immunocompromised Host; Influenza A Virus, H1N1 Subtype; Influenza, Human; Italy; Molecular Sequence Data; Mutation, Missense; Neuraminidase; Nose; Oseltamivir; RNA, Viral; Sequence Analysis, DNA; Treatment Outcome; Viral Load; Viral Proteins; Withholding Treatment

Data assessing the diagnostic accuracies of use of different respiratory samples for the detection of the novel influenza A/H1N1 2009 virus by molecular methods are lacking. The objective of this study was to compare the sensitivity of combined nose and throat swabs (CNTS) with that of nasopharyngeal aspirates (NPA). This was a prospective study of adults and children with suspected influenza. Real-time reverse transcriptase PCR testing was used for the virological diagnosis. Of the 2,473 patients included, 264 with paired CNTS and NPA were randomly selected. Novel influenza A/H1N1 virus was identified in at least one sample for 115 (43.6%) patients, the majority of them young adults. In 109 patients (94.8%) the virus was identified in the CNTS, and in 98 (85.2%) it was identified in the NPA (P = 0.02). In 93 patients (80.1%), the virus was identified in both specimens. Spearman's rho correlation coefficient between the two methods was 0.82 (P < 0.001). There were no significant differences in accuracy between the specimens when patients were stratified according to demographic or clinical characteristics except in the case of women, in whom the sensitivity of CNTS was higher (P = 0.01). The combination of CNTS and NPA had a significantly higher sensitivity in identifying the virus than did each method alone (P = 0.02 for the comparison of the combination of both sampling methods with CNTS, and P < 0.001 for the comparison with NPA). We conclude that in patients with the novel influenza A/H1N1 virus, the diagnostic yield of CNTS is higher than that of NPA. The combination of both sampling methods increases the likelihood of diagnosing the virus.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Female; Humans; Infant; Influenza A Virus, H1N1 Subtype; Influenza, Human; Male; Middle Aged; Nasopharynx; Nose; Pharynx; Prospective Studies; Random Allocation; Reverse Transcriptase Polymerase Chain Reaction; Sensitivity and Specificity; Virology; Young Adult

With the severe acute respiratory syndrome epidemic of 2003 and renewed attention on avian influenza viral pandemics, new surveillance systems are needed for the earlier detection of emerging infectious diseases. We applied a "next-generation" parallel sequencing platform for viral detection in nasopharyngeal and fecal samples collected during seasonal influenza virus (Flu) infections and norovirus outbreaks from 2005 to 2007 in Osaka, Japan. Random RT-PCR was performed to amplify RNA extracted from 0.1-0.25 ml of nasopharyngeal aspirates (N = 3) and fecal specimens (N = 5), and more than 10 microg of cDNA was synthesized. Unbiased high-throughput sequencing of these 8 samples yielded 15,298-32,335 (average 24,738) reads in a single 7.5 h run. In nasopharyngeal samples, although whole genome analysis was not available because the majority (>90%) of reads were host genome-derived, 20-460 Flu-reads were detected, which was sufficient for subtype identification. In fecal samples, bacteria and host cells were removed by centrifugation, resulting in gain of 484-15,260 reads of norovirus sequence (78-98% of the whole genome was covered), except for one specimen that was under-detectable by RT-PCR. These results suggest that our unbiased high-throughput sequencing approach is useful for directly detecting pathogenic viruses without advance genetic information. Although its cost and technological availability make it unlikely that this system will very soon be the diagnostic standard worldwide, this system could be useful for the earlier discovery of novel emerging viruses and bioterrorism, which are difficult to detect with conventional procedures.

Topics: Base Sequence; DNA, Bacterial; Feces; Gastroenteritis; Genetic Techniques; Humans; Influenza, Human; Molecular Sequence Data; Norovirus; Nose; Orthomyxoviridae; Reverse Transcriptase Polymerase Chain Reaction; RNA, Viral; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid

Rapid diagnosis of influenza can facilitate timely clinical management. We evaluated the performance of the QuickVue Influenza A + B test (Quidel, San Diego, CA) in a community setting and investigated the factors affecting test sensitivity. We recruited 1008 subjects from 30 outpatient clinics in Hong Kong between February and September 2007. Each subject provided 2 pooled pairs of nose and throat swabs; 1 pair was tested by the QuickVue rapid test on site, and the other pair was sent to a laboratory for reference tests. Among 998 enrolled subjects with valid results, the rapid test had overall sensitivity of 0.68 and specificity of 0.96 compared with viral culture. Sensitivity for both influenza A and B was significantly higher for specimens with viral loads greater than 5 log(10) copies/mL. The QuickVue Influenza A + B test has similar sensitivity in point-of-care community settings to more controlled conditions.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antigens, Viral; Child; Child, Preschool; Female; Hong Kong; Humans; Immunoassay; Infant; Influenza A virus; Influenza B virus; Influenza, Human; Male; Middle Aged; Nose; Pharynx; Point-of-Care Systems; Reagent Kits, Diagnostic; Sensitivity and Specificity; Young Adult

The objective of this study was to calculate sensitivity values for the detection of major respiratory viruses of childhood by using combined nose-throat swabs and nasopharyngeal aspirates.. Children who had symptoms and presented to a pediatric teaching hospital and had a diagnostic respiratory specimen collected were enrolled, and paired nose-throat swab and nasopharyngeal aspirate specimens were collected. Parents were asked to collect the nose-throat swab specimen in the first instance but could defer to a health care worker if unwilling. Nose-throat swab collectors were asked to rate perceived quality of collection. All nasopharyngeal aspirates were collected by a health care worker by using a standard protocol. Real-time polymerase chain reaction for 8 respiratory viruses was performed in our hospital's diagnostic laboratory.. Paired nose-throat swab/nasopharyngeal aspirate specimens were collected during 303 illnesses, with at least 1 respiratory virus identified in 186 (61%). For the major pathogens of childhood, influenza A virus and respiratory syncytial virus, collection by using the nose-throat swab had a sensitivity of 91.9% and 93.1%, respectively. A health care worker collected 219 (72%) of the nose-throat swab specimens; concordance with the nasopharyngeal aspirate was not related to health care worker collection or perceived quality of collection.. Nose-throat swab specimens, in combination with sensitive molecular testing, are a less invasive diagnostic respiratory specimen with adequate sensitivity for use in the clinic and hospital outpatient settings and large-scale community studies through parent collection. For children who present to a hospital in which an avian or pandemic strain of influenza virus is reasonably part of the differential diagnosis, nasopharyngeal aspirates or a similar collection technique (eg, nasal washes) should continue to be used.

Topics: Adolescent; Child; Child, Preschool; Diagnosis, Differential; DNA, Viral; Female; Humans; Incidence; Infant; Infant, Newborn; Influenza A virus; Influenza, Human; Male; Nasopharynx; Nose; Polymerase Chain Reaction; Queensland; Reproducibility of Results; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Retrospective Studies

Influenza virus and respiratory syncytial virus (RSV) are among the most common viruses causing infections of the lower respiratory tract in young children. Although there are important differences in the immunopathogenesis of these 2 viral pathogens, little is known about how they affect antigen-presenting cells in children with acute infections.. To characterize the immune cells that are mobilized to the respiratory tract by influenza virus and RSV, we analyzed nasal wash and blood samples obtained from children hospitalized with acute respiratory infections.. Influenza virus and RSV mobilize immune cells, including myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs), to the nasal mucosa. Patients with influenza virus infection had greater numbers of mDCs, pDCs, and monocytes in nasal wash samples than did patients with RSV infection. The frequencies of respiratory tract and blood T cell subsets were not affected by infection with influenza virus or RSV. Monocyte chemoattractant protein-1 concentrations in nasal wash samples were significantly increased in patients with influenza virus infection but not in those with RSV infection. RANTES (regulated on activation, normally T cell expressed and secreted) concentrations were increased only in the blood of patients with influenza virus infection.. Infection with influenza virus or RSV mobilizes antigen-presenting cells to the respiratory tract. The differences in antigen-presenting cell numbers and cytokine concentrations suggest that there are distinctive, early immune responses to these 2 viruses.

Topics: Chemokine CCL2; Chemokine CCL5; Child, Preschool; Cytokines; Dendritic Cells; Female; Humans; Infant; Infant, Newborn; Influenza, Human; Male; Monocytes; Nose; Orthomyxoviridae; Respiratory Mucosa; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; T-Lymphocyte Subsets

Calls to a UK national telephone health helpline (NHS Direct) have been used for syndromic surveillance, aiming to provide early warning of rises in community morbidity. We investigated whether self-sampling by NHS Direct callers could provide viable samples for influenza culture. We recruited 294 NHS Direct callers and sent them self-sampling kits. Callers were asked to take a swab from each nostril and post them to the laboratory. Forty-two per cent of the samples were returned, 16.2% were positive on PCR for influenza (16 influenza A(H3N2), three influenza A (H1N1), four influenza B) and eight for RSV (5.6%). The mean time between the NHS Direct call and laboratory analysis was 7.4 days. These samples provided amongst the earliest influenza reports of the season, detected multiple influenza strains, and augmented a national syndromic surveillance system. Self-sampling is a feasible method of enhancing community-based surveillance programmes for detection of influenza.

Topics: Adult; Aged; Aged, 80 and over; Female; Humans; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Influenza B virus; Influenza, Human; Male; Middle Aged; Nose; Polymerase Chain Reaction; Population Surveillance; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Self-Examination; Time Factors; United Kingdom

Institutional pandemic planning prompted a study of the molecular detection of influenza virus from respiratory specimens in children, compared to conventional diagnostics.. To evaluate the performance of a commercial qualitative real-time RT-PCR kit (rRT-PCR), the artus Influenza LC RT-PCR (Qiagen). STUDY DESIGN (METHODS): Specimens were pre-selected to include a high percentage of positives by direct immunofluorescence assay (DFA) or culture. The sensitivity and specificity of the kit for detection of influenza A and B in children were determined against the gold standard, DFA and culture. Specimens yielding discordant results between artus and the gold standard were tested against a reference rRT-PCR assay (Centers for Disease Control) to create an "expanded gold standard".. When compared to DFA or cell culture, the sensitivity of the rRT-PCR artus kit was 96.2% and the specificity was 94%. It detected influenza RNA in 6.0% of clinical samples negative by DFA or culture. Using the expanded gold standard, the revised sensitivity was 98.7% (98.6% for influenza A and 97.6% for influenza B) and the specificity was 100%.. The artus Influenza LC RT-PCR kit is an effective alternative to virus isolation and DFA for the detection of influenza A and B in pediatric clinical specimens.

Topics: Adolescent; Child; Child, Preschool; Fluorescent Antibody Technique, Direct; Humans; Infant; Infant, Newborn; Influenza A virus; Influenza B virus; Influenza, Human; Nose; Reagent Kits, Diagnostic; Reverse Transcriptase Polymerase Chain Reaction; RNA, Viral; Sensitivity and Specificity; Specimen Handling; Virus Cultivation

The 1918 influenza pandemic was a catastrophic series of virus outbreaks that spread across the globe. Here, we show that only a modest change in the 1918 influenza hemagglutinin receptor binding site alters the transmissibility of this pandemic virus. Two amino acid mutations that cause a switch in receptor binding preference from the human alpha-2,6 to the avian alpha-2,3 sialic acid resulted in a virus incapable of respiratory droplet transmission between ferrets but that maintained its lethality and replication efficiency in the upper respiratory tract. Furthermore, poor transmission of a 1918 virus with dual alpha-2,6 and alpha-2,3 specificity suggests that a predominant human alpha-2,6 sialic acid binding preference is essential for optimal transmission of this pandemic virus. These findings confirm an essential role of hemagglutinin receptor specificity for the transmission of influenza viruses among mammals.

Topics: Amino Acid Substitution; Animals; Cell Line; Disease Models, Animal; Dogs; Ferrets; Galactose; Glycoconjugates; Hemagglutinin Glycoproteins, Influenza Virus; Humans; Influenza A Virus, H1N1 Subtype; Influenza, Human; Lung; Male; Mutation; Nose; Receptors, Virus; Respiratory System; Sialic Acids; Virulence; Virus Replication; Virus Shedding

We have prepared a virus-like particle (VLP) vaccine bearing the surface glycoproteins HA and NA of the 1918 influenza A virus by infecting Sf9 cells with a quadruple recombinant baculovirus that expresses the four influenza proteins (HA, NA, M1, and M2) required for the assembly and budding of the VLPs. The presence of HA and M1 in the purified VLPs was confirmed by Western blot, and that of NA by a neuraminidase enzymatic assay. For in vivo studies, the 1918 VLP vaccine was formulated with or without an oligonucleotide containing two CpG motifs and administered in two doses 2 wk apart via the intranasal route. The antibody titers in mice immunized with VLP vaccines were higher than in mice vaccinated with an inactivated swine virus (H1N1) control, when CHO cells expressing 1918 HA were used as antigen. The opposite result was obtained when disrupted swine virus was the antigen for the ELISA test. Vaccine efficacy was evaluated by challenging immunized mice with the 1918 antigenically related influenza virus A/swine/Iowa/15/30 (H1N1) and measuring viral titers in the upper and lower respiratory tract. Mice immunized with VLP vaccine plus CpG demonstrated significantly lower viral titers in the nose and lungs than did the control on days 2 and 4 postchallenge and completely cleared the virus by day 6. Furthermore, they did not show symptoms of disease although there was a minor decrease in body weight. Mice vaccinated with VLP alone also demonstrated significantly lower viral titers in the nose and lungs than did the placebo group as well as the inactivated virus group on days 4 and 6 postchallenge. These results suggest that it is feasible to make a safe and immunogenic vaccine to protect against the extremely virulent 1918 virus, using a novel and safe cell-based technology.

Topics: Adjuvants, Immunologic; Administration, Intranasal; Animals; Antibodies, Viral; Body Weight; Female; Hemagglutinins, Viral; Humans; Influenza A Virus, H1N1 Subtype; Influenza Vaccines; Influenza, Human; Lung; Mice; Mice, Inbred BALB C; Neuraminidase; Nose; Oligodeoxyribonucleotides; Orthomyxoviridae Infections; Placebos; Vaccines, Virosome; Viral Matrix Proteins; Viral Proteins; Viral Vaccines

Topics: Genetic Predisposition to Disease; Humans; Indonesia; Influenza A Virus, H5N1 Subtype; Influenza, Human; International Cooperation; Nose; Pharynx; Rural Health; Time Factors; Treatment Refusal; Viral Load; World Health Organization

The Quidel QuickVue influenza test was compared to viral culture and reverse transcriptase PCR by the use of three different respiratory specimen types. Of 122 pediatric subjects enrolled, 59 had influenza virus infections: 44 were infected with influenza A virus and 15 were infected with influenza B virus. The sensitivity of the QuickVue test was 85% with nasopharyngeal swabs, 78% with nasal swabs, and 69% with nasopharyngeal washes. Specificities were equivalent (97% to 98%) for all three collection methods.

Topics: Adolescent; Child; Child, Preschool; Emergency Medicine; Female; Humans; Infant; Infant, Newborn; Influenza A virus; Influenza B virus; Influenza, Human; Male; Nasopharynx; Nose; Reagent Kits, Diagnostic; Reverse Transcriptase Polymerase Chain Reaction; Sensitivity and Specificity; Virus Cultivation

Currently, little is known about the viral kinetics of influenza A during infection within an individual. We utilize a series of mathematical models of increasing complexity, which incorporate target cell limitation and the innate interferon response, to examine influenza A virus kinetics in the upper respiratory tracts of experimentally infected adults. The models were fit to data from an experimental H1N1 influenza A/Hong Kong/123/77 infection and suggest that it is important to include the eclipse phase of the viral life cycle in viral dynamic models. Doing so, we estimate that after a delay of approximately 6 h, infected cells begin producing influenza virus and continue to do so for approximately 5 h. The average lifetime of infected cells is approximately 11 h, and the half-life of free infectious virus is approximately 3 h. We calculated the basic reproductive number, R(0), which indicated that a single infected cell could produce approximately 22 new productive infections. This suggests that antiviral treatments have a large hurdle to overcome in moderating symptoms and limiting infectiousness and that treatment has to be initiated as early as possible. For about 50% of patients, the curve of viral titer versus time has two peaks. This bimodal behavior can be explained by incorporating the antiviral effects of interferon into the model. Our model also compared well to an additional data set on viral titer after experimental infection and treatment with the neuraminidase inhibitor zanamivir, which suggests that such models may prove useful in estimating the efficacies of different antiviral therapies for influenza A infection.

Topics: Administration, Intranasal; Adult; Antiviral Agents; Guanidines; Humans; Influenza A Virus, H1N1 Subtype; Influenza, Human; Interferons; Kinetics; Models, Theoretical; Nose; Pyrans; Sialic Acids; Zanamivir

Viral culture isolation has been widely accepted as the "gold standard" for laboratory confirmation of viral infection; however, it requires ultralow temperature specimen storage. Storage of specimens in ethanol at room temperature could expand our ability to conduct active surveillance and retrospective screenings of viruses with rapid and inexpensive real-time PCR tests, including isolates from remote regions where freezing specimens for culture is not feasible. Molecular methods allow for rapid identification of viral pathogens without the need to maintain viability. We hypothesized that ethanol, while inactivating viruses, can preserve DNA and RNA for PCR-based methods. To evaluate the use of ethanol-stored specimens for augmenting surveillance for detection of influenza viruses A and B and adenoviruses (AdV), paired nasal swab specimens were collected from 384 recruits with febrile respiratory illness at Fort Jackson, S.C., in a 2-year study. One swab was stored at ambient temperature in 100% ethanol for up to 6 months, and the other swab was stored at -70 degrees C in viral medium. For viral detection, frozen specimens were cultured for a variety of respiratory viruses, and ethanol-fixed specimens were tested with TaqMan (TM) probe and LightCycler SYBR green (SG) melting curve assays with at least two different PCR targets for each virus. The sensitivities of the TM and SG assays on specimens stored in ethanol for 1 month were 75% and 58% for influenza A, 89% and 67% for influenza B, and 93 to 98% and 57% for AdV, respectively. Lower specificities of the real-time assays corresponded to the increased detection of PCR-positive but culture-negative specimens. Influenza virus RNA was detected as well or better after 6 months of storage in ethanol.

Topics: Adenovirus Infections, Human; Adenoviruses, Human; DNA, Viral; Ethanol; Humans; Influenza A virus; Influenza B virus; Influenza, Human; Military Personnel; Nose; Polymerase Chain Reaction; Population Surveillance; Predictive Value of Tests; RNA, Viral; Sensitivity and Specificity; Specimen Handling

Topics: Child; Female; Humans; Infant; Influenza A virus; Influenza, Human; Male; Meningoencephalitis; Nose; Treatment Outcome

Despite the clinical importance of influenza virus in pediatric respiratory infections, the optimal set of diagnostic tests to use when conducting studies using archival samples is not clear. In this study, we compared diagnostic tests for influenza virus in 75 children younger than 5 years of age who presented with symptomatic respiratory infection during one of four influenza seasons, had negative viral cultures for other respiratory pathogens, and had both an archival nasal aspirate obtained at the time of illness and serology spanning that influenza season. For all eligible children, we compared the results of viral culture performed at the time of collection with serology and PCR of archival nasal aspirates. Using real-time viral culture as the "gold standard," the test characteristics of PCR of archival nasal aspirates (sensitivity, 82%; specificity, 100%) and serology (sensitivity, 82%; specificity, 87%) were similar. The relatively low sensitivity of PCR of archival nasal samples in this study compared to that of PCR of fresh samples in a previous study suggests that RNA degradation occurred despite storage of the specimens at -70 degrees C. RNA degradation would also explain why only 11 (52%) of 21 archival nasal samples that had positive influenza virus cultures at the time of collection had positive repeat cultures in the summer of 2000. Thus, in archival specimens stored at -70 degrees C, PCR was more sensitive than viral culture. However, testing of fresh specimens had the highest yield in this study. Studies of optimal methods for specimen storage are needed.

Topics: Child, Preschool; Follow-Up Studies; Humans; Infant; Infant, Newborn; Influenza A virus; Influenza B virus; Influenza, Human; Longitudinal Studies; Nose; Polymerase Chain Reaction; Specimen Handling

New rapid diagnostic methods are needed to identify influenza infections to improve virological surveillance usually undertaken with conventional time-consuming, complex, and even expensive laboratory methods. Another reason for using a rapid test is to avoid inappropriate therapy, particularly in children, where use of antibiotics inappropriately and high influenza-related rates of hospitalisation are described. During two winter seasons, the performance of the QuickVue Influenza test (QV) was evaluated in children under 14 presenting with influenza like illness, and compared the results with those obtained from sentinel network surveillance using standard protocols for the sample collection and the laboratory analysis by virus culture and reverse transcription-polymerase chain reaction (RT-PCR). During the first influenza season (2000/2001), 22 paediatricians collected one nose- and one throat-swab from each of the 586 children 0-6 years old recruited in the study. The QV test was carried out in the physician's office by primary care staff on the nose swab material. When compared with virus culture of the throat swab, the QV test had a sensitivity of 36.5%. In the following 2001/2002-influenza season, the performance of the QV test as a rapid laboratory screening assay was assessed. 342 children aged 0-14 years were enrolled with only one throat swab collected from each patient and sent to the laboratory where the QV, virus culture, and RT-PCR tests were performed. The results showed a better sensitivity (54.5%) of the test in comparison with virus culture and RT-PCR assays. The data indicate that rapid QV testing in the physician office setting, using these easily obtained samples, may be too insensitive to be useful for surveillance and for immediate clinical management of children presenting with influenza-like illness. Nevertheless, the QV test may be a valuable diagnostic tool if used in laboratory, as a rapid screening test.

Topics: Animals; Antigens, Viral; Cell Line; Child; Dogs; Humans; Immunoassay; Influenza A virus; Influenza B virus; Influenza, Human; Nose; Pharynx; Population Surveillance; Reagent Kits, Diagnostic; Reverse Transcriptase Polymerase Chain Reaction; RNA, Viral; Sensitivity and Specificity; Virus Cultivation; Virus Replication

The importance of rapid diagnosis of influenza has increased with the availability of neuraminidase inhibitors, which need to be commenced within 48 hr of symptom onset. Furthermore, the recent development of influenza-like clinical syndromes with novel aetiologies (severe acute respiratory syndrome, SARS) has increased the need for rapid and accurate near-patient diagnosis. A new, modified point of care (POC) diagnostic test (ZstatFlu) was assessed on 469 nasopharyngeal aspirates (NPAs) and 260 nose/throat swabs (TS) taken from children and adults. The test was specific (77-98%) for all specimen types for influenza virus A and B, depending upon incubation conditions. However, it was less sensitive, detecting 65-77% of specimens confirmed as positive on culture, direct immunofluorescence or PCR testing. A positive test is useful, for both directing initiation of therapy in the clinician's office, and making a positive diagnosis of influenza in patients with influenza-like clinical syndromes.

Topics: Adolescent; Aged; Child; Child, Preschool; Fluorescent Antibody Technique, Direct; Humans; Infant; Influenza A virus; Influenza B virus; Influenza, Human; Middle Aged; Nasopharynx; Neuraminidase; Nose; Pharynx; Point-of-Care Systems; Quality of Health Care; Reverse Transcriptase Polymerase Chain Reaction; Sensitivity and Specificity; Severe Acute Respiratory Syndrome

Surveillance of winter respiratory viral illness has been carried out for nearly 30 years using a clinical diagnosis by general practitioners as part of the Scottish Sentinel General Practice (SSGP) network. Contemparaneous laboratory diagnosis has not been available previously.. To assess the proportion of influenza-like illness (ILI) attributable to influenza, respiratory syncytial virus (RSV) and picornavirus infection during the winter season. To compare the influenza PCR data with serology of paired blood samples.. Combined nose and throat swabs, from patients with ILI attending 15 general practices across Scotland, were submitted to the laboratory in virus PCR sample solution (VPSS). The extracted nucleic acid was tested using a multiplex reverse-transcription polymerase chain reaction (RT-PCR) assay. Serological analysis was performed on paired serum samples using complement fixation assays. The rate of influenza virus positivity was compared with reports of ILI obtained from the SSGP network.. Of 240 samples received at the laboratory, 132 (55%) were PCR positive for influenza A virus. There were nine (3.8%) picornavirus and three (1.2%) RSV PCR positives, two (0.8%) were dual influenza A/picornavirus infections. Ninety four (39.2%) were negative for all viruses tested. Results on paired sera from 89 patients showed a rising titre to influenza A in 48 of the 57 PCR positive samples (84.2%). One PCR negative patient displayed a significant rising titre to influenza A. Virological data paralleled the SSGP data but was available at least a week earlier.. Influenza A infection was detected in the majority of patients with ILI; picornavirus infection was also shown to be an important cause of illness. PCR is a rapid and sensitive method for respiratory virus surveillance. Serology is slow, insensitive and difficult to interpret at low titres.

Topics: Adolescent; Adult; Aged; Antibodies, Viral; Child; Child, Preschool; Community-Acquired Infections; Complement Fixation Tests; Female; Humans; Influenza, Human; Male; Middle Aged; Nose; Orthomyxoviridae; Pharynx; Picornaviridae; Picornaviridae Infections; Population Surveillance; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Reverse Transcriptase Polymerase Chain Reaction; Scotland

The economic impact and medical complication rate of viral upper respiratory infections are well documented, but many of the physiologic, inflammatory, and immune responses to respiratory viruses have only recently been investigated. A previous study demonstrated differential systemic immune and inflammatory responses in allergic rhinitis (AR) and nonallergic rhinitis (NAR) subjects during experimental infection with rhinovirus-39.. The purpose of this study was to compare selected systemic immune and inflammatory responses to experimental influenza A virus (FLU) challenge in seronegative AR and NAR subjects.. Peripheral blood was obtained at baseline (study day 0) and 3, 6, 18, and 31 days after intranasal FLU challenge and assayed for leukocyte histamine release, serum immunoglobulins, and plasma histamine.. All subjects were infected, as manifested by viral shedding in nasal secretions and/or seroconversion. FLU infection induced decreases in spontaneous leukocyte histamine release and increases in anti-immunoglobulin E-induced leukocyte histamine release, which were evident at least 1 month after infection, but caused no significant changes in serum immunoglobulins or plasma histamine. There were no differences between AR and NAR subjects for any of the study parameters.. The results show that intranasal challenge with FLU induces changes in leukocyte histamine release, but not other systemic immune and inflammatory responses.

Topics: Adolescent; Adult; Female; Histamine; Histamine Release; Humans; Immunoglobulin E; Influenza A virus; Influenza, Human; Male; Nose; Rhinitis; Rhinitis, Allergic, Perennial; Virus Shedding

Intramuscular (IM) influenza vaccines are about 50% effective in preventing clinical illness among the elderly and their effectiveness in eliciting mucosal response may be even lower. The aim of the present study was to evaluate the immunological effect of a novel inactivated intranasal (IN) trivalent whole influenza virus vaccine among community-dwelling elderly. Sixty-one subjects were vaccinated with two doses of an IN vaccine and a control group of 31 subjects was vaccinated with a commercial IM vaccine. Viral strains in the 1997/8 vaccine used were A/Nanchang/933/95(H3N2), A/Johannesburg/82/96(H1N1) and B/Harbin/7/94. Serum IgG and nasal IgA were determined by HI and ELISA, respectively. Only a few minor local adverse events were reported after vaccination. Seroconversion for the three antigens tested was higher after IM vaccination, although not statistically significant. Local antibody response to the three antigens tested was detected in 50-53% and 19-26% of IN and IM immunized subjects, respectively. The IN vaccine tested was significantly more effective than the IM vaccine in inducing mucosal IgA response. This may prevent influenza at its early stages and thus contribute to the reduction of complications in the elderly.

Topics: Administration, Intranasal; Aged; Aged, 80 and over; Antibody Formation; Female; Humans; Influenza Vaccines; Influenza, Human; Injections, Intramuscular; Male; Middle Aged; Nose; Vaccination

Demand for the rapid diagnosis of influenza infections has increased with the advent of the availability of neuraminidase antiviral therapy for influenza A and B. Several rapid assays that detect both influenza A and B are now available.. In this study we compared the performance of the BioStar FLU OIA assay to Bartels Viral Respiratory Screening and Identification Kit (Bartels Inc., Issaquah, WA), and cell culture.. A total of 145 patient specimens for influenza virus detection submitted in either viral transport medium or in sterile containers were evaluated by the three methods. Specimen types included nasal washings, nasal swabs, sputum, throat swabs, and bronchial alveolar lavage (BAL) fluids.. Fifty six positive specimens were identified based on culture and/or DFA. Of these, 30 specimens were positive by the OIA assay for an overall sensitivity of 54%. The OIA assay detected 48% (n = 21) of the 44 culture positive specimens and 81% (n = 29) of the 36 DFA positive specimens. Eighty six of the 89 culture/DFA negative samples were negative by the OIA assay (97% specificity). Analysis of the OIA assay sensitivity from samples submitted in M4 transport medium or in sterile containers revealed that M4 transport medium does not reduce the sensitivity of the OIA assay. Fifteen of the 27 positive samples submitted in M4 transport medium were positive by the OIA assay (56% sensitivity) compared to 15 of 29 positive samples transported in sterile containers (52% sensitivity). Twelve specimens were either culture and/or DFA positive for viruses other than influenza, but negative by the OIA assay, suggesting that there was no cross reactivity of the OIA assay with the other virus types recovered in this study.. The overall excellent specificity of the BioStar FLU OIA allows for treatment of positive patients for influenza, however, a negative result should be confirmed by DFA and culture.

Topics: Animals; Antigens, Viral; Bronchoalveolar Lavage Fluid; Cell Line; Fluorescent Antibody Technique, Direct; Humans; Immunoassay; Influenza A virus; Influenza B virus; Influenza, Human; Nasal Lavage Fluid; Nose; Pharynx; Sensitivity and Specificity; Sputum

A strain of Streptococcus pneumoniae, when inoculated intranasally in 2 microl of suspension into BALB/c mice preinfected with influenza virus, colonized first in the nose, and several days thereafter also colonized significantly in the trachea and lungs with purulent inflammation. Pneumoccocal colonization was also observed in the noses of normal mice after the same bacterial inoculation, but not apparently in the lower respiratory tract. These results suggest that pneumococcal infection may develop from the upper to the lower respiratory tract as a possible sequence preferentially in influenza virus-infected subjects.

Topics: Animals; Humans; Influenza A virus; Influenza, Human; Lung; Mice; Mice, Inbred BALB C; Nose; Pneumococcal Infections; Streptococcus pneumoniae; Superinfection; Trachea

Although laboratory diagnosis of respiratory viruses has been widely studied, there is a relative insufficiency of literature examining the impact of specimen type on the laboratory diagnosis of influenza A and B. In a clinical study comparing the FLU OIA test with 14-day cell culture, clinical specimens from nasopharyngeal swabs, throat swabs, nasal aspirates, and sputum were obtained from patients experiencing influenza-like symptoms. A total of 404 clinical specimens were collected from 184 patients. Patients were defined as influenza positive if the viral culture of a specimen from any sample site was positive. Patients were defined as influenza negative if the viral cultures of specimens from all sample sites were negative. By this gold standard, culture and FLU OIA test results for each sample type were compared. For each of the four specimen types, the viral culture and FLU OIA test demonstrated equal abilities to detect the presence of influenza A or B virus or viral antigen. Sputum and nasal aspirate samples were the most predictive of influenza virus infection. Throat swabs were the least predictive of influenza virus infection, with both tests failing to detect influenza virus in nearly 50% of the throat samples studied.

Topics: Humans; Immunoassay; Influenza A virus; Influenza B virus; Influenza, Human; Nasopharynx; Nose; Pharynx; Reverse Transcriptase Polymerase Chain Reaction; Sensitivity and Specificity; Specimen Handling; Sputum; Virus Cultivation

Topics: Disease Outbreaks; England; Humans; Incidence; Influenza A virus; Influenza B virus; Influenza, Human; Nose; Pharynx; Population Surveillance; Seasons

Past studies showed that experimental rhinovirus colds in adults resulted in eustachian tube dysfunction and abnormal middle ear pressures. In the present study, the symptoms and pathophysiologic findings accompanying experimental influenza viral infection were documented. A total of 33 healthy adult volunteers were intranasally challenged with an influenza A/Kawasaki/86 (H1N1) virus and cloistered over a 9-day postchallenge period to monitor for evidence of infection, signs and symptoms of illness, and the extent and frequency of pathophysiologic responses of the nose, eustachian tube, and middle ear. Results showed a protective effect of high (> or = 16) prechallenge specific hemagglutination-inhibition antibody titer on the rate of infection and the magnitude and extent of provoked symptoms and pathophysiologic findings. Infected subjects with low (< 16) prechallenge serum antibody titers (n = 21) developed significant respiratory illness. These subjects also had objectively measurable increases in nasal secretion production, and decreased nasal patency and mucociliary clearance rates. More than 80% of the infected subjects developed eustachian tube dysfunction, and approximately 80% had middle ear underpressures of less than -100 mm H2O on study days 4 and 5. Five of 21 infected subjects with low prechallenge antibody titers had otoscopic evidence of otitis media with effusion. These results support a causal role for viral upper respiratory tract infection in the pathogenesis of otitis media, possibly mediated by the early development of eustachian tube dysfunction and abnormal middle ear pressure.

Topics: Adult; Body Temperature; Ear, Middle; Eustachian Tube; Female; Humans; Influenza A virus; Influenza, Human; Male; Mucociliary Clearance; Nasal Lavage Fluid; Nasal Provocation Tests; Nose; Pressure; Reaction Time

Nine cases of severe hypotension or death compatible with toxic shock syndrome (TSS) as a complication of influenza and influenzalike illness were identified in Minnesota with onsets between Jan 2, 1986, and Feb 23, 1986, in which five of the patients died. During this time, an influenza outbreak was occurring in the state. Cultures of respiratory secretions were performed in eight patients; Staphylococcus aureus was isolated from all of them. Seven S aureus isolates were available for determination of exotoxin production; five isolates produced toxic shock syndrome toxin-1, one produced enterotoxin B, and one produced both. Acute influenza B infection was confirmed in three of four patients for whom throat cultures or acute and convalescent serum samples were available. Two patients fulfilled the Centers for Disease Control-confirmed case definition for TSS. Four additional patients fulfilled the CDC criteria for a probable case of TSS, and TSS was a likely diagnosis in the remaining three patients. The initial presentation was suggestive of nonsuppurative tracheitis or viral pneumonia in eight patients. In the remaining patient, the initial clinical presentation was compatible with staphylococcal pneumonia. This report demonstrates that TSS can occur as a complication of influenza and influenzalike illness.

Topics: Adolescent; Adult; Carrier State; Child; Child, Preschool; Disease Outbreaks; Female; Humans; Influenza, Human; Male; Minnesota; Nose; Pharynx; Prospective Studies; Retrospective Studies; Shock, Septic; Staphylococcal Infections; Staphylococcus aureus

To determine whether respiratory virus infections (URI) are associated with exacerbation of nephrotic syndrome (NS) in childhood, a prospective two-winter study of 32 children with NS was done. We obtained pre- and post-season viral serologic studies, biweekly nose and throat viral cultures, daily urinalysis, biweekly telephone follow-up for URI and renal complaints, and clinical assessments as indicated. When a URI occurred, viral cultures were done weekly if the child was at home and twice weekly if hospitalized. Sixty-one URIs occurred; the agent was identified in 33 (51.6%) (respiratory syncytial virus 14, influenza virus five, parainfluenza virus five, varicella zoster virus four, adenovirus three, Mycoplasma pneumoniae one, and Chlamydia trachomatis one). Forty-one exacerbations occurred, 71% with URI; 29% had no URI during the preceding 10 days (P less than 0.01). Total relapse occurred in 29 of 41 exacerbations, 69% with URI and 31% without URI (P less than 0.01). Patients with unstable NS had more exacerbations than those with stable NS (15 of 19 (79%) vs four of 13 (31%), P less than 0.001) and more URI (2.32 vs 1.46 per child, P less than 0.05). Exacerbations in patients with minimal change, mesangioproliferative, and focal glomerulosclerosis occurred in 40%, 60%, and 64%, respectively. We conclude that exacerbations and relapses of childhood NS are temporally related to URI. Inasmuch as multiple viral agents were associated with exacerbations, nonspecific host response to infection, not viral antigen or antibody response, may be the link to NS.

Topics: Adolescent; Adult; Chickenpox; Child; Child, Preschool; Female; Follow-Up Studies; Humans; Infant; Influenza, Human; Male; Nephrotic Syndrome; Nose; Orthomyxoviridae; Paramyxoviridae Infections; Pharynx; Prospective Studies; Recurrence; Respiratory Syncytial Viruses; Respiratory Tract Infections; Respirovirus; Seasons; Surveys and Questionnaires; Virus Diseases

The effects of simultaneous inoculation with two attenuated influenza A viruses was studied in ferrets and volunteers. Groups of ferrets were inoculated with an influenza A (H3N2) or (H1N1), virus or a combination of both viruses: the temperature response, serum and local antibody response, and the change in nasal wash protein concentration was determined. The results showed that both viruses were attenuated for ferrets, and that inoculation with both viruses together did not cause clinical reactions. Serological studies on paired serum samples obtained from ferrets showed that both viruses when given separately infected all the inoculated animals; however, dual infection resulted in all ferrets being infected with the influenza A (H3N2) virus strain, but this infection interfered with infection by the influenza A (H1N1) strain. Similar investigations were carried out in volunteers. Again, the clinical reactions and temperature response of volunteers to infection by one or other of the viruses showed both strains to be attenuated for man even when given together. In addition, no adverse clinical reactions were seen in volunteers inoculated with both viruses simultaneously. Serum antibody studies showed that infection by influenza A (H1N1) virus interfered with infection by the influenza A (H2N2) virus strain. These results show evidence of interference by influenza A viruses; however, the direction of interference was one-way, and differed for ferrets and for volunteers.

Topics: Animals; Antibodies, Viral; Body Temperature; Carnivora; Ferrets; Humans; Influenza Vaccines; Influenza, Human; Nose; Vaccination; Vaccines, Attenuated

An intranasal, inactivated trivalent influenza A vaccine containing 7 micrograms of A/Bangkok/1/79 (H3N2) hemagglutinin was administered to 20 children aged 1 to 6 years to assess the local and systemic immune responses to antigen delivered to the respiratory tract. Six children without prior influenza virus infection exhibited no local immune response and manifested only a minimal systemic response to the intranasal vaccine. In contrast, five individuals who were previously infected with a live attenuated influenza A H3N2 virus vaccine, although having no residual secretory antibody at the time of challenge, promptly developed a local antibody response to intranasal, inactivated antigen. Therefore, the live influenza A virus vaccine had induced memory in the local immunoglobulin A (IgA) immune system. The third group of nine children had previously been infected with wild-type H3N2 influenza virus. A majority of these children had residual local and systemic antibody at the time of challenge but they demonstrated some boosting of local IgA antibody with administration of intranasal inactivated vaccine. The competence of the secretory IgA immune system in young children in mounting primary and secondary responses to influenza antigens has important implications for approaches to prevention of influenzal illness.

Topics: Administration, Intranasal; Antibodies, Viral; Child; Child, Preschool; Enzyme-Linked Immunosorbent Assay; Humans; Immunoglobulin A; Immunoglobulin A, Secretory; Immunologic Memory; Infant; Influenza A virus; Influenza Vaccines; Influenza, Human; Neutralization Tests; Nose; Vaccination; Vaccines, Attenuated

The isotype-specific antibody responses to purified hemagglutinin of adults undergoing either primary or secondary infection with an influenza A virus were characterized by using an enzyme-linked immunosorbent assay. Twenty-eight military recruits undergoing primary infection with A/USSR/92/77 (H1N1)-like virus had serum antibody rises in the immunoglobulin M (IgM) (86%), IgG (100%), and IgA (96%) isotypes. In contrast, 19 adult volunteers undergoing secondary infection with A/Peking/2/79 (H3N2) wild-type virus had serum antibody titer rises largely restricted to the IgG (68%) and IgA (74%) classes, with only 1 volunteer having a serum IgM antibody titer rise. Nasal wash hemagglutinin-specific antibody responses in the adults undergoing secondary infection were predominantly in the IgA class (74%). There was a correlation between the presence of and the magnitude of nasal wash and serum hemagglutinin-specific IgA antibody responses in these adults. This suggested that there was a common source for the hemagglutinin-specific local IgA antibody and serum IgA antibody produced after infection. The recruits undergoing primary H1N1 influenza virus infection had H1 hemagglutinin-specific enzyme-linked immunosorbent assay antibody in each of the IgA, IgG, and IgM isotypes in their acute-phase serum. However, no role for this cross-reactive antibody in modifying the severity of illness experienced by the recruits could be demonstrated.

Topics: Adult; Antibody Specificity; Cross Reactions; Enzyme-Linked Immunosorbent Assay; Hemagglutinins, Viral; Humans; Immunoglobulin A; Immunoglobulin Allotypes; Immunoglobulin G; Immunoglobulin M; Influenza A virus; Influenza, Human; Male; Nose

After intranasal instillation into ferrets, the "swine" influenza virus A/New Jersey/8/76(Hsw1 N1) had a 50% minimal infectious dose similar to that of previously tested A/PR/8-A/England (H3 N2) recombinants virulent and attenuated for man. A/New Jersey produced only a mild upper respiratory tract infection. However, higher titres of virus were recovered from the lungs over a longer period than experienced previously with Asian and Hong Kong virus strains. There was a diphasic pyrexia the second and higher peaks of which correlated with peak titres of virus in lung macerates. These results suggest that A/New Jersey has a pneumotropic potential in ferrets and, if the animal model is valid, possible in man.

Topics: Animals; Carnivora; Disease Models, Animal; Ferrets; Fever; Humans; Influenza A virus; Influenza, Human; Lung; Nose; Pneumonia, Viral; Virulence

The sequential development of the immune response in nasal washings was studied in 54 volunteers immunized with either attenuated or inactivated influenza B/Eng/13/65 virus vaccines.Eleven of the 15 volunteers given the inactivated vaccine by deep subcutaneous inoculation showed no rise in nasal wash protein or immunoglobins due to the immunization procedure nor was specific neutralizing antibody detected in their nasal washings after immunization. Neutralizing antibody was detected in nasal washings of three volunteers in this group who also showed a 20-fold or greater increase in serum haemagglutinin-inhibiting antibody after immunization and in one volunteer who had antibody present in pre-trial nasal washings.Eleven of 15 volunteers who were successfully infected by the live attenuated vaccine showed a characteristic rise in protein and IgA and IgG immunoglobin concentrations in nasal washings 5-14 days after the administration of the live virus vaccine. Neutralizing antibody was detected in the nasal washings of these 11 volunteers and appeared at the same time as or 1-2 days after the initial rise of protein and immunoglobin. Neutralizing antibody was also detected in the nasal washings of one other volunteer who did not show a rise in protein or immunoglobin concentration in nasal washings after immunization.IgA was detected (>/= 3 mg./100 ml.) in the majority (84%) of nasal wash specimens which had a protein concentration of 0.2 mg./ml. or greater while IgG was not detected (>/= 4.5 mg./100 ml.) until the protein concentration rose to 0.4 mg./ml. or greater. The geometric mean concentration for normal nasal wash protein in this study was 0.3 +/- 0.1 mg./ml.Regression analysis indicated that the concentrations of both IgA and IgG immunoglobins were directly proportional to the protein concentration in nasal washings but that this relationship varied considerably between individuals.Absorption studies indicated that neutralizing and haemagglutinin-inhibiting antibodies in nasal secretion to influenza B/Eng/13/65 virus were predominantly associated with the IgA class of immunoglobin.

Topics: Antibodies; Complement Fixation Tests; Hemagglutination Inhibition Tests; Humans; Immunization; Immunoglobulin A; Immunoglobulin G; Immunoglobulin M; Immunoglobulins; Influenza Vaccines; Influenza, Human; Injections, Subcutaneous; Nasal Mucosa; Neutralization Tests; Nose; Proteins; Time Factors

Topics: Aerosols; Humans; Influenza Vaccines; Influenza, Human; Nose; Vaccination

Topics: Adjuvants, Immunologic; Aerosols; Antibody Formation; Antigens, Viral; Attitude to Health; Body Temperature; Genetics, Microbial; Humans; Immunogenetics; Influenza Vaccines; Influenza, Human; Male; Nose; Orthomyxoviridae; United States; Vaccination; Vaccines, Attenuated; Virus Replication

Forty-nine subjects were vaccinated with either live attenuated, detergent split, or oil adjuvant A2/Hong Kong influenza vaccines, or a saline influenza B vaccine as control. Respiratory symptoms occurred more frequently in subjects who received the live vaccine but in total there was little difference between the symptoms in the four groups. Antibody titres in nasal washings and serum were measured by haemagglutination inhibition, neuraminidase inhibition and virus neutralization tests. The oil adjuvant vaccine stimulated larger antibody responses than the other procedures. Six weeks after vaccination the volunteers were challenged with partially attenuated live A2/Hong Kong influenza virus administered intranasally. The live attenuated and oil adjuvant vaccines provided the best protection against challenge.

Topics: Adjuvants, Immunologic; Adult; Antibodies; Antibody Formation; Detergents; Female; Hemagglutination Inhibition Tests; Humans; Immunity; Influenza Vaccines; Influenza, Human; Male; Neuraminidase; Neutralization Tests; Nose; Orthomyxoviridae; Vaccination

Rhesus monkeys and ferrets were exposed to intranasal inoculation of several strains of egg-adapted avian, equine and human influenza viruses and to strains of mouse-adapted equine influenza viruses. Local replication of virus and seroconversion were observed in the majority of these animals. However, clinical infection was observed only in ferrets.

Topics: Animals; Antigen-Antibody Reactions; Birds; Carnivora; Cross Reactions; Haplorhini; Hemagglutination Inhibition Tests; Horses; Humans; Immune Sera; Influenza, Human; Monkey Diseases; Nose; Orthomyxoviridae; Respiratory Tract Infections; Turkeys; Virus Replication

Topics: Adenoviridae; Adenoviridae Infections; Complement Fixation Tests; Culture Techniques; Exudates and Transudates; Fluorescent Antibody Technique; Humans; Influenza, Human; Methods; Mobile Health Units; Mycoplasma; Mycoplasma Infections; Netherlands; Nose; Orthomyxoviridae; Paramyxoviridae Infections; Pharynx; Respiratory Syncytial Viruses; Respiratory Tract Infections; Respirovirus; Sputum; Time Factors; Virus Diseases

Topics: Administration, Oral; Animals; Antibodies; Bronchi; Female; Humans; Immune Sera; Immunization; Immunoglobulins; Influenza Vaccines; Influenza, Human; Injections; Injections, Intraperitoneal; Injections, Subcutaneous; Mice; Mice, Inbred Strains; Neutralization Tests; Nose; Species Specificity; Sputum

Topics: Aerosols; Age Factors; Antibodies; Antibody Formation; Complement Fixation Tests; Hemagglutination Inhibition Tests; Humans; Influenza Vaccines; Influenza, Human; Injections, Intradermal; Injections, Subcutaneous; Neutralization Tests; Nose; Vaccination

Topics: Absenteeism; Aerosols; Age Factors; Aged; Antibodies; Antibody Formation; Complement Fixation Tests; Hemagglutination Inhibition Tests; Humans; Influenza Vaccines; Influenza, Human; Injections, Subcutaneous; Neutralization Tests; Nose; Population Surveillance; United States; Vaccination

Topics: Adult; Aged; Animals; Autopsy; Bronchi; Child, Preschool; Cough; Culture Techniques; Fluorescent Antibody Technique; Haplorhini; Humans; Immune Sera; Infant; Influenza, Human; Kidney; Lung; Middle Aged; Nasopharynx; Nose; Respiratory Syncytial Viruses; Trachea

Topics: Adolescent; Adult; Aged; Bronchi; Cadaver; Fluorescent Antibody Technique; Humans; Influenza, Human; Lung; Middle Aged; Nose; Postmortem Changes; Staphylococcal Infections; Time Factors; Trachea

Topics: Adolescent; Age Factors; Aged; Animals; Antibodies; Antigen-Antibody Reactions; Antigens; Child; Female; gamma-Globulins; Hemadsorption Inhibition Tests; Hemagglutination Inhibition Tests; Humans; Immune Sera; Immunoelectrophoresis; Immunoglobulin G; Influenza Vaccines; Influenza, Human; Japan; Male; Maryland; Massachusetts; Methods; Mice; Michigan; Middle Aged; Nasal Mucosa; Nasopharynx; National Institutes of Health (U.S.); Neuraminidase; Nose; Taiwan; United States; Vaccination

Topics: Adult; Aged; Antigens; Epithelium; Female; Fluorescent Antibody Technique; Humans; Influenza, Human; Male; Middle Aged; Nose; Orthomyxoviridae; Prognosis; Time Factors

Topics: Cytodiagnosis; Fluorescent Antibody Technique; Humans; Influenza, Human; Microscopy, Fluorescence; Nose

Topics: Animals; Cattle; Cattle Diseases; Colostrum; Female; Hemagglutination Inhibition Tests; Influenza, Human; Lung; Neutralization Tests; Nose; Orthomyxoviridae; Orthomyxoviridae Infections; Paramyxoviridae Infections; Pathology; Pregnancy; Research; Sheep; Sheep Diseases; Swine Diseases; Virus Cultivation

Topics: Fluorescent Antibody Technique; Humans; Influenza, Human; Nose; Orthomyxoviridae; Research

Topics: Administration, Intranasal; Animals; Humans; Immunity; Influenza, Human; Mice; Nose; Orthomyxoviridae; Peritoneal Cavity; Research

Topics: Animals; Cattle; Cattle Diseases; Epidemiology; Exudates and Transudates; gamma-Globulins; Hemagglutination Inhibition Tests; Illinois; Influenza, Human; Neutralization Tests; Nose; Orthomyxoviridae; Orthomyxoviridae Infections; Paramyxoviridae Infections; Respiratory Tract Infections; Virus Cultivation

Topics: Cytodiagnosis; Fluorescence; Humans; Influenza, Human; Nose; Staining and Labeling

Topics: Haemophilus influenzae; Haemophilus influenzae type b; Humans; Influenza, Human; Nasopharynx; Nose; Pharynx; School Health Services

Topics: Air Conditioning; Anti-Bacterial Agents; Bacterial Infections; Cross Infection; Escherichia coli; Haemophilus influenzae; Humans; Influenza, Human; Nose; Pharynx; Pneumonia; Pneumonia, Viral; Pseudomonas aeruginosa; Staphylococcus; Sterilization; Streptococcus pneumoniae; Tetracycline

Topics: Humans; Influenza, Human; Nose; Vaccination

Topics: Common Cold; Humans; Influenza, Human; Larynx; Nose; Trachea

Topics: Communism; Humans; Influenza, Human; Nose; Vaccination

Topics: Common Cold; Humans; Influenza, Human; Larynx; Nose; Rhinitis; Ultraviolet Rays; Ultraviolet Therapy

Topics: Child; Common Cold; Croup; Humans; Infant; Influenza, Human; Larynx; Nose; Trachea

Topics: Autonomic Nervous System Diseases; Common Cold; Diagnosis, Differential; Humans; Influenza, Human; Larynx; Nose; Trachea

Topics: Anti-Bacterial Agents; Antibiotics, Antitubercular; Biomedical Research; Common Cold; Humans; Influenza, Human; Nose; Penicillins; Pharynx; Protamines; Trachea

Topics: Disease; Hearing; Hearing Disorders; Humans; Influenza, Human; Nervous System Diseases; Nose; Parotitis; Pharynx

Topics: Common Cold; Humans; Influenza, Human; Larynx; Nose; Trachea

Topics: Common Cold; Humans; Influenza, Human; Larynx; Nose; Trachea

Topics: Humans; Influenza, Human; Larynx; Nose; Trachea

Topics: Ear; Ear Diseases; Humans; Influenza, Human; Nasal Cavity; Nose; Paranasal Sinuses

Topics: Animals; Humans; Influenza, Human; Mice; Mucus; Nasal Mucosa; Nose; Orthomyxoviridae

Topics: Hemorrhage; Humans; Influenza, Human; Nose