phenylephrine-hydrochloride and Orthomyxoviridae-Infections

Limited information is available on the transmission and spread of influenza virus in pig populations with differing immune statuses. In this study we assessed differences in transmission patterns and quantified the spread of a triple reassortant H1N1 influenza virus in naïve and vaccinated pig populations by estimating the reproduction ratio (R) of infection (i.e. the number of secondary infections caused by an infectious individual) using a deterministic Susceptible-Infectious-Recovered (SIR) model, fitted on experimental data. One hundred and ten pigs were distributed in ten isolated rooms as follows: (i) non-vaccinated (NV), (ii) vaccinated with a heterologous vaccine (HE), and (iii) vaccinated with a homologous inactivated vaccine (HO). The study was run with multiple replicates and for each replicate, an infected non-vaccinated pig was placed with 10 contact pigs for two weeks and transmission of influenza evaluated daily by analyzing individual nasal swabs by RT-PCR. A statistically significant difference between R estimates was observed between vaccinated and non-vaccinated pigs (p < 0.05). A statistically significant reduction in transmission was observed in the vaccinated groups where R (95%CI) was 1 (0.39-2.09) and 0 for the HE and the HO groups respectively, compared to an Ro value of 10.66 (6.57-16.46) in NV pigs (p < 0.05). Transmission in the HE group was delayed and variable when compared to the NV group and transmission could not be detected in the HO group. Results from this study indicate that influenza vaccines can be used to decrease susceptibility to influenza infection and decrease influenza transmission.

Topics: Animals; Antibodies, Viral; Enzyme-Linked Immunosorbent Assay; Influenza A Virus, H1N1 Subtype; Influenza Vaccines; Lung; Nose; Orthomyxoviridae Infections; Reassortant Viruses; Swine; Swine Diseases; Vaccines, Inactivated

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

Topics: A549 Cells; Amino Acid Substitution; Animals; Antiviral Agents; Dibenzothiepins; Dogs; Drug Resistance, Viral; Guinea Pigs; Humans; Influenza A Virus, H3N2 Subtype; Madin Darby Canine Kidney Cells; Morpholines; Nose; Orthomyxoviridae Infections; Pyridones; Reverse Genetics; RNA-Dependent RNA Polymerase; Triazines; Viral Load; Viral Proteins; Virus Replication

Swine influenza is an economically important respiratory disease in swine, but it also constantly poses a threat to human health. Therefore, developing rapid, sensitive, and efficient detection methods for swine influenza virus (SIV) is important. By aligning the haemagglutinin (HA) gene sequences of SIVs circulating in China over a 10-year period, an H1 primer-probe set targeting both Eurasian avian-like H1N1 (EA H1N1) and pandemic 2009 H1N1 ((H1N1)pdm09) lineages plus a H3 primer-probe set targeting the prevalent human-like H3N2 (HL H3N2) subtype were designed. Subsequently, a TaqMan-MGB-based duplex one-step real-time RT-PCR (RT-qPCR) assay was established and evaluated. The duplex RT-qPCR has a detection limit of 5 copies/μL of HA plasmid for EA H1N1, (H1N1)pdm09, and HL H3N2 subtype SIVs, and its overall detection sensitivity of 100% and specificity of 91.67% matches that of traditional virus isolation through chicken embryo inoculation using experimentally infected mouse lung samples. The method showed high repeatability both within run and between runs, and there was no cross-reactivity against several other porcine viruses that are commonly circulating in China. Furthermore, the duplex RT-qPCR method revealed a higher prevalence of subtype H1 than subtype H3 in 166 nasal swabs from pigs collected from one slaughterhouse between October and December 2019. This assay could be very helpful in the rapid differential detection and routine surveillance of EA H1N1, (H1N1)pdm09, and HL H3N2 SIVs in China.

Topics: Animals; China; Disease Models, Animal; Early Diagnosis; Female; Hemagglutinin Glycoproteins, Influenza Virus; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Mice; Multiplex Polymerase Chain Reaction; Nose; Orthomyxoviridae Infections; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Sensitivity and Specificity; Swine

In 2012 and 2013, the genomic sequences of two novel influenza A virus (IAV) subtypes, designated H17N10 and H18N11, were identified via next-generation sequencing in the feces of the little yellow-shouldered fruit bat (

Topics: Animals; Antibodies, Neutralizing; Antibodies, Viral; Chiroptera; Feces; Host Specificity; Influenza A virus; Intestines; Mouth; Nasal Mucosa; Nose; Orthomyxoviridae Infections; Rhinitis; Virus Replication

Topics: Amino Acid Substitution; Animals; Animals, Newborn; Antigens, Viral; Evolution, Molecular; Female; Genetic Drift; Hemagglutinin Glycoproteins, Influenza Virus; Mutation; Nose; Orthomyxoviridae Infections; Phylogeny; Swine

Human cases of H7N9 influenza A virus infection have been increasing since 2013. The first choice of treatment for influenza is neuraminidase (NA) inhibitors (NAIs), but there is a concern that NAI-resistant viruses are selected in the presence of NAIs. In our previous study, an H7N9 virus carrying AA substitution of threonine (T) for isoleucine (I) at residue 222 in NA (NA222T, N2 numbering) and an H7N9 virus carrying AA substitution of lysine (K) for arginine (R) at residue 292 in NA (NA292K, N2 numbering) were found in different macaques that had been infected with A/Anhui/1/2013 (H7N9) and treated with NAIs. In the present study, the variant with NA292K showed not only resistance to NAIs but also lower replication activity in MDCK cells than did the virus with wild-type NA, whereas the variant with NA222T, which was less resistant to NAIs, showed replication activity similar to that of the wild-type virus. Next, we examined the pathogenicity of these H7N9 NAI-resistant viruses in macaques. The variants caused clinical signs similar to those caused by the wild-type virus with similar replication potency. However, the virus with NA292K was replaced within 7 days by that with NA292R (same as the wild-type) in nasal samples from macaques infected with the virus with NA292K, i.e. the so-called revertant (wild-type virus) became dominant in the population in the absence of an NAI. These results suggest that the clinical signs observed in macaques infected with the NA292K virus are caused by the NA292K virus and the NA292R virus and that the virus with NA292K may not replicate continuously in the upper respiratory tract of patients without treatment as effectively as the wild-type virus.

Topics: Amino Acid Substitution; Animals; Antiviral Agents; Drug Resistance, Viral; Enzyme Inhibitors; Influenza A Virus, H7N9 Subtype; Macaca fascicularis; Mutation; Neuraminidase; Nose; Orthomyxoviridae Infections; Pneumonia, Viral; Respiratory System; Selection, Genetic; Viral Proteins; Virus Replication

Staphylococcus aureus is found in the nasal cavity of up to 30% of the human population. Persistent nasal carriage of S. aureus is a risk factor for influenza virus-induced secondary bacterial pneumonia. There is limited understanding of the factors that cause S. aureus to shift from the upper to the lower respiratory tract and convert from a commensal organism to an invasive pathogen. Here we show that neutrophils actively prevent S. aureus dissemination. Establishment of a mouse model of localized S. aureus nasal carriage revealed variations in the longevity of persistence of S. aureus isolates. Improved persistence within this site was associated with reduced nasal inflammation, less neutrophil egress into the airways and reduced neutrophil-bacteria association. Neutrophil depletion of mice with localized S. aureus nasal carriage triggered the development of an invasive S. aureus infection. Moreover, utilizing a model of influenza-induced staphylococcal pneumonia we showed that treatment with granulocyte-colony-stimulating factor, a potent enhancer of neutrophil number and function, significantly reduced bacterial loads in the lung and improved disease outcomes. These data reveal that neutrophils play an important and active role in confining S. aureus to the upper respiratory tract and highlight the use of approaches that improve neutrophil function as effective strategies to attenuate morbidity associated with staphylococcal pneumonia.

Topics: Animals; Lung; Mice; Neutrophils; Nose; Orthomyxoviridae Infections; Pneumonia, Staphylococcal; Staphylococcus aureus

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

Swine influenza is one of the important zoonotic diseases of pigs. We conducted a longitudinal survey of swine influenza A viruses (S-IAV) circulating in a pig farm with history of endemic S-IAV infection from 2017 to 2018. The samples were collected from 436 pigs including nasal swab samples (n = 436) and blood samples (n = 436). Our result showed that 18.81% (82/436) were positive for influenza A virus and subsequently 57 S-IAV could be isolated. Then 24 out of 57 S-IAVs were selected for whole genome sequencing and could be subtyped as S-IAV-H1N1 (n = 18) and S-IAV-H3N2 (n = 6). Of 24 S-IAVs, we observed 3 genotypes of S-IAVs including rH1N1 (pdm + 1), rH1N1 (pdm + 2), and rH3N2 (pdm + 2). Since all genotypes of S-IAVs in this study contained internal genes from pdmH1N1-2009, it could be speculated that pdmH1N1-2009 was introduced in a pig farm and then multiple reassorted with endemic S-IAVs to generate diversify S-IAV genotypes. Our study supported and added the evidences that pdmH1N1-2009 and it reassortant have predominately persisted in pig population in Thailand. Thus, monitoring of S-IAVs in pigs, farm workers and veterinarians in pig farms is important and should be routinely conducted.

Topics: Animals; Animals, Domestic; Blood; Genotyping Techniques; Influenza A Virus, H1N1 Subtype; Longitudinal Studies; Nose; Orthomyxoviridae Infections; Phylogeny; Reassortant Viruses; RNA, Viral; Swine; Thailand; Whole Genome Sequencing

Influenza A virus infection is a global health threat to livestock and humans, causing substantial mortality and morbidity. As both pigs and humans are readily infected with influenza viruses of similar subtype, the pig is a robust and appropriate model for investigating swine and human disease. We evaluated the efficacy of the human cold-adapted 2017-2018 quadrivalent seasonal LAIV in pigs against H1N1pdm09 challenge. LAIV immunized animals showed significantly reduced viral load in nasal swabs. There was limited replication of the H1N1 component of the vaccine in the nose, a limited response to H1N1 in the lung lymph nodes and a low H1N1 serum neutralizing titer. In contrast there was better replication of the H3N2 component of the LAIV, accompanied by a stronger response to H3N2 in the tracheobronchial lymph nodes (TBLN). Our data demonstrates that a single administration of human quadrivalent LAIV shows limited replication in the nose and induces detectable responses to the H1N1 and H3N2 components. These data suggest that pigs may be a useful model for assessing LAIV against influenza A viruses.

Topics: Administration, Intranasal; Animals; Antibodies, Neutralizing; Cold Temperature; Cytokines; Female; HEK293 Cells; Humans; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Influenza Vaccines; Lung; Lymph Nodes; Nose; Orthomyxoviridae Infections; Seasons; Swine; Vaccines, Attenuated

Influenza B viruses (IBVs) have never been isolated from natural-infected pigs in clinical cases, although the susceptibility of domestic pigs to experimental IBV infections had been confirmed as well as IBV-specific antibodies were detected from pigs under natural and experimental conditions.. We aimed to assess and investigate the activities for infection and circulation of IBVs in pigs.. Annual active surveys for influenza have been implemented on swine populations in Taiwan since July 1998. Nasal swabs, trachea, lungs, and blood from pigs were tested using virological and serological assays for influenza. Gene sequences of influenza viral isolates were determined and characterized. Preliminary sero-epidemiological data for influenza virus were investigated.. Three strains of IBV were isolated and identified from natural-infected pigs in 2014. Genetic characterization revealed the highest identities (>99%) of molecular sequence with the contemporary IBVs belonged to the B/Brisbane/60/2008 genetic clade of Victoria lineage in the phylogenetic trees for all 8 genes. IBV-specific antibodies were detected in 31 (0.2%; 95%CI: 0.1%-0.2%) of 15 983 swine serum samples from 29 (2.8%; 95%CI: 1.9%-3.9%) of 1039 farm visits under annual active surveys from 2007 through 2017. Seropositive cases have been found sparsely in 1-5 of test prefectures every year except 2015 and 2017 as well as scattered loosely over 26 townships/districts of 11 prefectures in Taiwan cumulatively in 11 years.. Influenza B viruse infections from humans to pigs remained sporadic and accidental currently in Taiwan but might have paved potential avenues for newly emerging zoonotic influenza in the future.

Topics: Animals; Antibodies, Viral; Farms; Influenza B virus; Nose; Orthomyxoviridae Infections; Phylogeny; Serologic Tests; Sus scrofa; Swine; Swine Diseases; Taiwan; Virus Replication

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

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

Influenza B virus is a main causative pathogen of annual influenza epidemics, however, research on influenza B virus in general lags behind that on influenza A viruses, one of the important reasons is studies on influenza B viruses in animal models are limited. Here we investigated the tree shrew as a potential model for influenza B virus studies.. Tree shrews and ferrets were inoculated with either a Yamagata or Victoria lineage influenza B virus. Symptoms including nasal discharge and weight loss were observed. Nasal wash and respiratory tissues were collected at 2, 4 and 6 days post inoculation (DPI). Viral titers were measured in nasal washes and tissues were used for pathological examination and extraction of mRNA for measurement of cytokine expression.. Clinical signs and pathological changes were also evident in the respiratory tracts of tree shrews and ferrets. Although nasal symptoms including sneezing and rhinorrhea were evident in ferrets infected with influenza B virus, tree shrews showed no significant respiratory symptoms, only milder nasal secretions appeared. Weight loss was observed in tree shrews but not ferrets. V0215 and Y12 replicated in all three animal (ferrets, tree shrews and mice) models with peak titers evident on 2DPI. There were no significant differences in peak viral titers in ferrets and tree shrews inoculated with Y12 at 2 and 4DPI, but viral titers were detected at 6DPI in tree shrews. Tree shrews infected with influenza B virus showed similar seroconversion and respiratory tract pathology to ferrets. Elevated levels of cytokines were detected in the tissues isolated from the respiratory tract after infection with either V0215 or Y12 compared to the levels in the uninfected control in both animals. Overall, the tree shrew was sensitive to infection and disease by influenza B virus.. The tree shrew to be a promising model for influenza B virus research.

Topics: Animals; Antibodies, Viral; Cytokines; Disease Models, Animal; Female; Ferrets; Influenza B virus; Male; Mice; Mice, Inbred BALB C; Nose; Orthomyxoviridae Infections; Respiratory System; Trees; Tupaiidae; Viral Load; Virus Replication

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

Equine influenza, caused by the H3N8 subtype, is a highly contagious respiratory disease affecting equid populations worldwide and has led to serious epidemics and transboundary pandemics. This study describes the phylogenetic characterization and replication kinetics of recently-isolated H3N8 virus from a nasal swab obtained from a sporadic case of natural infection in an unvaccinated horse from Montana, USA. The nasal swab tested positive for equine influenza by Real-Time Quantitative Reverse Transcription Polymerase Chain Reaction (RT-PCR). Further, the whole genome sequencing of the virus confirmed that it was the H3N8 subtype and was designated as A/equine/Montana/9564-1/2015 (H3N8). A BLASTn search revealed that the polymerase basic protein 1 (PB1), polymerase acidic (PA), hemagglutinin (HA), nucleoprotein (NP), and matrix (M) segments of this H3N8 isolate shared the highest percentage identity to A/equine/Tennessee/29A/2014 (H3N8) and the polymerase basic protein 2 (PB2), neuraminidase (NA), and non-structural protein (NS) segments to A/equine/Malaysia/M201/2015 (H3N8). Phylogenetic characterization of individual gene segments, using currently available H3N8 viral genomes, of both equine and canine origin, further established that A/equine/Montana/9564-1/2015 belonged to the Florida Clade 1 viruses. Interestingly, replication kinetics of this H3N8 virus, using airway derived primary cells from multiple species, such as equine, swine, bovine, and human lung epithelial cells, demonstrated appreciable titers, when compared to Madin-Darby canine kidney epithelial cells. These findings indicate the broad host spectrum of this virus isolate and suggest the potential for cross-species transmissibility.

Topics: A549 Cells; Animals; Cattle; Dogs; Genes, Viral; Horse Diseases; Horses; Humans; Influenza A Virus, H3N8 Subtype; Madin Darby Canine Kidney Cells; Neuraminidase; Nose; Orthomyxoviridae Infections; Phylogeny; RNA, Viral; Swine; Vaccination; Whole Genome Sequencing

Influenza A virus (IAV) is a zoonotic pathogen threatening animal and public health; therefore, detection and monitoring of IAV in animal populations are critical components of a surveillance program. Swine are important hosts of IAV, wherein the virus can undergo rapid evolution. Several methods (i.e., nasal swabs, nasal wipes, and oral fluids) have been used to collect samples from swine for IAV surveillance. We utilized nasal wipes made from cotton gauze and multiple, polyester or mixed polyester fabrics to compare performance in the molecular detection and isolation of IAV. In vitro experiments revealed that no polyester or mixed polyester fabric was superior to cotton gauze for molecular IAV detection; however, 3 polyester or mixed polyester fabrics yielded significantly more viable IAV than cotton. In a field trial, both cotton gauze and the polyester or mixed polyester fabric yielded similar proportions of IAV isolates from swine. The results indicate that cotton gauze remains a practical and useful material for swine nasal wipes.

Topics: Animals; Diagnostic Techniques and Procedures; Influenza A virus; Nose; Orthomyxoviridae Infections; Sentinel Surveillance; Specimen Handling; Swine; Swine Diseases

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 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

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

The increasing diversity of influenza strains circulating in swine herds escalates the potential for the emergence of novel pandemic viruses and highlights the need for swift development of new vaccines. Baculovirus has proven to be a flexible platform for the generation of recombinant forms of hemagglutinin (HA) including subunit, VLP-displayed, and baculovirus-displayed antigens. These presentations have been shown to be efficacious in mouse, chicken, and ferret models but little is known about their immunogenicity in pigs. To assess the utility of these HA presentations in swine, Baculovirus constructs expressing HA fused to swine IgG2a Fc, displayed in a FeLV gag VLP, or displayed in the baculoviral envelope were generated. Vaccines formulated with these antigens wer The e administered to groups of pigs who were subsequently challenged with H1α cluster H1N1 swine influenza virus (SIV) A/Swine/Indiana/1726/88. Our results demonstrate that vaccination with any of these three vaccines elicits robust hemagglutinin inhibition titers in the serum and decreased the severity of SIV-associated lung lesions after challenge when compared to placebo-vaccinated controls. In addition, the number of pigs with virus detected in the lungs and nasal passages was reduced. Taken together, the results demonstrate that these recombinant approaches expressed with the baculovirus expression vector system may be viable options for development of SIV vaccines for swine.

Topics: Animals; Antibodies, Viral; Baculoviridae; Cell Line; Hemagglutinin Glycoproteins, Influenza Virus; Influenza A Virus, H1N1 Subtype; Influenza Vaccines; Lung; Nose; Orthomyxoviridae Infections; Random Allocation; Swine; Swine Diseases; Vaccines, Subunit; Vaccines, Synthetic

The study of influenza type A (IA) infections in wild mammals populations is a critical gap in our knowledge of how IA viruses evolve in novel hosts that could be in close contact with avian reservoir species and other wild animals. The aim of this study was to evaluate the susceptibility to infection, the nasal shedding and the transmissibility of the H7N1 and H5N1 highly pathogenic avian influenza (HPAI) viruses in the bank vole (Myodes glareolus), a wild rodent common throughout Europe and Asia. Two out of 24 H5N1-infected voles displayed evident respiratory distress, while H7N1-infected voles remained asymptomatic. Viable virus was isolated from nasal washes collected from animals infected with both HPAI viruses, and extra-pulmonary infection was confirmed in both experimental groups. Histopathological lesions were evident in the respiratory tract of infected animals, although immunohistochemistry positivity was only detected in lungs and trachea of two H7N1-infected voles. Both HPAI viruses were transmitted by direct contact, and seroconversion was confirmed in 50% and 12.5% of the asymptomatic sentinels in the H7N1 and H5N1 groups, respectively. Interestingly, viable virus was isolated from lungs and nasal washes collected from contact sentinels of both groups. The present study demonstrated that two non-rodent adapted HPAI viruses caused asymptomatic infection in bank voles, which shed high amounts of the viruses and were able to infect contact voles. Further investigations are needed to determine whether bank voles could be involved as silent hosts in the transmission of HPAI viruses to other mammals and domestic poultry.

Topics: Animals; Arvicolinae; Disease Susceptibility; Influenza A Virus, H5N1 Subtype; Influenza A Virus, H7N1 Subtype; Nose; Orthomyxoviridae Infections; Rodent Diseases; Virus Shedding

Equine influenza (EI) is a highly contagious respiratory disease of horses.. The aim of this study was to evaluate two rapid antigen detection kits (Directigen or DFA, and Espline) and a commercial ELISA for the detection of EI nucleoprotein in nasal swabs.. Nasal swab samples from naturally and experimentally infected horses were used to compare the sensitivity and specificity of these assays to virus isolation (VI) and real-time RT-PCR.. If real-time RT-PCR was considered as the gold standard, the sensitivity of the other tests in field samples was 68% (DFA), 35% (ELISA), 29% (Espline), and 9% (VI). These tests had 100% specificity when compared to real-time RT-PCR. A receiver operating characteristic (ROC) curve indicated that decreasing the cutoff of the ELISA would increase sensitivity with some loss of specificity. In samples from experimentally infected horses, the sensitivity of the tests compared with real-time RT-PCR was 69% (VI), 27% (DFA), 6% (Espline), and 2% (ELISA). The specificity was 100% for Espline and ELISA and 95% for VI and DFA.. This study illustrated that DFA is the most sensitive antigen detection test evaluated for the diagnosis of EI and that it can detect virus in some subclinical infected and vaccinated horses. The results suggest that DFA is a useful adjunct to laboratory tests and may be effective as a screening test in a quarantine station or similar facility where horses are monitored daily.

Topics: Animals; Diagnostic Tests, Routine; Enzyme-Linked Immunosorbent Assay; Horse Diseases; Horses; Nose; Nucleocapsid Proteins; Orthomyxoviridae Infections; Reagent Kits, Diagnostic; RNA-Binding Proteins; Sensitivity and Specificity; Viral Core Proteins

H6N1 avian influenza A viruses, which have spread across North America, Europe and Asia, have been shown to be infectious not only for birds but also for mammals. Because humans lack immunity to H6N1 avian influenza A viruses, the emergence of these viruses in humans would probably cause a pandemic. Replication of H6N1 avian influenza A viruses in dogs may facilitate their adaptation in humans because dogs are often in close contact with humans. However, the susceptibility of dogs to these viruses is unknown. To address this question, we infected beagles intranasally (i.n.) with an H6N1 avian influenza A virus that was isolated from a mallard. Inoculation of this virus into beagles resulted in the virus being detectable in the lung and seroconversion with no clinical signs except for a fever at 1 day post-inoculation (dpi). In addition, the virus was transiently shed from the nose and in the feces of the infected beagles. Our results suggest that dogs can be subclinically infected with H6N1 avian influenza A viruses, which, like H7N9, have low pathogenicity in birds and may serve as an intermediate host to transfer this virus to humans. Certain actions may be taken to prevent the potential transmission of these viruses, including the development of H6N1 avian influenza vaccines for prevention.

Topics: Animals; Birds; Disease Models, Animal; Dogs; Feces; Host Specificity; Influenza A virus; Influenza in Birds; Lung; Molecular Sequence Data; Nose; Orthomyxoviridae Infections; RNA, Viral; Sequence Analysis, DNA; Virus Shedding

Swine influenza is a disease of the respiratory tract caused by influenza A virus (IAV). Experimental inoculation of pigs involves either aerosolization and inhalation of virus or the direct introduction of virus into the upper or lower respiratory tract. This chapter covers methods for experimental IAV infection of pigs and collection of specific samples to study the pathogenesis of swine influenza and vaccine efficacy.

Topics: Animals; Bronchoalveolar Lavage Fluid; Influenza A virus; Influenza Vaccines; Nose; Orthomyxoviridae Infections; Phenotype; Swine; Trachea

Sporadic influenza A virus (IAV) outbreaks in humans and swine have resulted from commingling of large numbers of people and pigs at agricultural fairs in the United States. Current antemortem IAV surveillance strategies in swine require collecting nasal swabs, which entails restraining pigs with snares. Restraint is labor-intensive for samplers, stressful for pigs, and displeasing to onlookers because pigs often resist and vocalize.. To evaluate the utility of snout wipes in exhibition swine as a method to make IAV surveillance efforts less intrusive, less labor-intensive, and more widely accepted among pig owners and exhibition officials.. Three materials (rayon/polyester gauze, cotton gauze, and Swiffer(®) Sweeper dry cloths) were inoculated with IAV, and viral recoveries from these materials were quantified using qRT-PCR and TCID50 assays. In a field trial, paired cotton gauze snout wipes and gold standard polyester-tipped nasal swabs were collected from 553 pigs representing 29 agricultural fairs and the qualitative results of rRT-PCR and viral isolation were compared.. Viral recoveries from potential snout wipe materials ranged from 0.26 to 1.59 log10 TCID50 /ml less than that of the positive control in which no substrate was included; rayon/polyester gauze performed significantly worse than the other materials. In the field, snout wipes and nasal swabs had high levels of agreement for both rRT-PCR detection and virus isolation. Although further investigation and refinement of the sampling method is needed, results indicate that snout wipes will facilitate convenient and undisruptive IAV surveillance in pigs at agricultural fairs.

Topics: Animals; Diagnostic Techniques and Procedures; Female; Indiana; Influenza A virus; Male; Nose; Ohio; Orthomyxoviridae Infections; Sentinel Surveillance; Swine; Swine Diseases

H2N2 Influenza A caused the Asian flu pandemic in 1957, circulated for more than 10 years and disappeared from the human population after 1968. Given that people born after 1968 are naïve to H2N2, that the virus still circulates in wild birds and that this influenza subtype has a proven pandemic track record, H2N2 is regarded as a potential pandemic threat. To prepare for an H2N2 pandemic, here we developed and tested in mice and ferrets two live attenuated influenza vaccines based on the haemagglutinins of the two different H2N2 lineages that circulated at the end of the cycle, using the well characterized A/Leningrad/134/17/57 (H2N2) master donor virus as the backbone. The vaccine strains containing the HA and NA of A/California/1/66 (clade 1) or A/Tokyo/3/67 (clade 2) showed a temperature sensitive and cold adapted phenotype and a reduced reproduction that was limited to the respiratory tract of mice, suggesting that the vaccines may be safe for use in humans. Both vaccine strains induced haemagglutination inhibition titers in mice. Vaccination abolished virus replication in the nose and lung and protected mice from weight loss after homologous and heterologous challenge with the respective donor wild type strains. In ferrets, the live attenuated vaccines induced high virus neutralizing, haemagglutination and neuraminidase inhibition titers, however; the vaccine based on the A/California/1/66 wt virus induced higher homologous and better cross-reactive antibody responses than the A/Tokyo/3/67 based vaccine. In line with this observation, was the higher virus reduction observed in the throat and nose of ferrets vaccinated with this vaccine after challenge with either of the wild type donor viruses. Moreover, both vaccines clearly reduced the infection-induced rhinitis observed in placebo-vaccinated ferrets. The results favor the vaccine based on the A/California/1/66 isolate, which will be evaluated in a clinical study.

Topics: Animals; Antibodies, Neutralizing; Antibodies, Viral; Drug Evaluation, Preclinical; Female; Ferrets; Gene Expression; Hemagglutinins, Viral; Humans; Immunization; Influenza A Virus, H2N2 Subtype; Influenza Vaccines; Lung; Mice; Mice, Inbred CBA; Neuraminidase; Nose; Orthomyxoviridae Infections; Pandemics; Reassortant Viruses; Vaccines, Attenuated; Virus Replication

Interactions between the viral surface glycoprotein haemagglutinin (HA) and the corresponding receptors on host cells is one important aspect of influenza virus infection. Mutations in HA have been described to affect pathogenicity, antigenicity and the transmission of influenza viruses. Here, we detected polymorphisms present in HA genes of two pandemic 2009 H1N1 (H1N1pdm09) isolates, A/California/04/2009 (Ca/09) and A/Mexico/4108/2009 (Mx/09), that resulted in amino acid changes at positions 186 (S to P) and 194 (L to I) of the mature HA1 protein. Although not reported in the published H1N1pdm09 consensus sequence, the P186 genotype was more readily detected in primary infected and contact-naïve pigs when inoculated with a heterogeneous mixed stock of Ca/09. Using reverse genetics, we engineered Ca/09 and Mx/09 genomes by introducing Ca/09 HA with two naturally occurring variants expressing S186/I194 (HA-S/I) and P186/L194 (HA-P/L), respectively. The Ca/09 HA with the combination of P186/L194 with either the Ca/09 or Mx/09 backbone resulted in higher and prolonged viral shedding in naïve pigs. This efficiency appeared to be more likely through an advantage in cell surface attachment rather than replication efficiency. Although these mutations occurred within the receptor-binding pocket and the Sb antigenic site, they did not affect serological cross-reactivity. Relative increases of P186 in publicly available sequences from swine H1N1pdm09 viruses supported the experimental data, indicating this amino acid substitution conferred an advantage in swine.

Topics: Animals; Gene Expression Regulation, Viral; Hemagglutinin Glycoproteins, Influenza Virus; Influenza A Virus, H1N1 Subtype; Nose; Orthomyxoviridae Infections; Polymorphism, Genetic; Swine; Swine Diseases; Virus Shedding

Streptococcus pneumoniae (pneumococcus) is both a widespread nasal colonizer and a leading cause of otitis media, one of the most common diseases of childhood. Pneumococcal phase variation influences both colonization and disease and thus has been linked to the bacteria's transition from colonizer to otopathogen. Further contributing to this transition, coinfection with influenza A virus has been strongly associated epidemiologically with the dissemination of pneumococci from the nasopharynx to the middle ear. Using a mouse infection model, we demonstrated that coinfection with influenza virus and pneumococci enhanced both colonization and inflammatory responses within the nasopharynx and middle ear chamber. Coinfection studies were also performed using pneumococcal populations enriched for opaque or transparent phase variants. As shown previously, opaque variants were less able to colonize the nasopharynx. In vitro, this phase also demonstrated diminished biofilm viability and epithelial adherence. However, coinfection with influenza virus ameliorated this colonization defect in vivo. Further, viral coinfection ultimately induced a similar magnitude of middle ear infection by both phase variants. These data indicate that despite inherent differences in colonization, the influenza A virus exacerbation of experimental middle ear infection is independent of the pneumococcal phase. These findings provide new insights into the synergistic link between pneumococcus and influenza virus in the context of otitis media.

Topics: Animals; Carrier State; Coinfection; Influenza A virus; Mice; Nose; Orthomyxoviridae Infections; Otitis Media; Pneumococcal Infections; Streptococcus pneumoniae

While influenza viruses are typically considered respiratory pathogens, the ocular system represents a secondary entry point for virus to establish a productive respiratory infection and the location for rare instances of virus-induced conjunctivitis. We used the ferret model to conduct a side-by-side comparison of virus infectivity, kinetics of viral replication, and induction of host responses following inoculation by either the intranasal or ocular routes with two viruses, A/Netherlands/230/03 (H7N7) and A/Panama/2007/99 (H3N2). We show that ocular inoculation resulted in delayed virus replication and reduced levels of proinflammatory cytokine and chemokine transcript in respiratory tract but not ocular tissues compared with intranasally inoculated animals. We identified numerous proinflammatory mediators with known roles in ocular disease elicited in ferret eye tissue following influenza virus infection. These findings provide a greater understanding of the modulation of host responses following different inoculation routes and underscore the risk associated with ocular exposure to influenza viruses.

Topics: Animals; Chemokines; Conjunctiva; Cytokines; Disease Models, Animal; Eye; Eye Infections, Viral; Ferrets; Influenza A Virus, H3N2 Subtype; Influenza A Virus, H7N7 Subtype; Nose; Orthomyxoviridae Infections; Respiratory System; Respiratory Tract Infections; RNA, Viral; Virus Replication

Several cases of humans infected with the H9N2 avian influenza virus (AIV) have been described since 1999; however, the infectivity and pathogenicity of H9N2 in humans is not well defined. A non-human primate model in rhesus macaques was developed to study H9N2 virus infections as a means of better understanding the pathogenesis and virulence of this virus, in addition to testing antiviral drugs. Rhesus macaques inoculated with H9N2 AIV presented with biphasic fever and viral pneumonia. H9N2 was recovered from nasal washes and pharyngeal samples up to days 7-9 postinfection, followed by an increase in HI (hemagglutination inhibition) antibody titers. Tissue tropism and immunohistochemistry indicated that H9N2 AIV replicated in the upper respiratory tract (turbinate, trachea, and bronchus) and in all lobes of the lung. Our data suggest that rhesus macaques are a suitable animal model to study H9N2 influenza virus infections, particularly in the context of viral evolution and pathogenicity.

Topics: Animals; Female; Influenza A Virus, H9N2 Subtype; Macaca mulatta; Nose; Orthomyxoviridae Infections; Pharynx; Time Factors; Tissue Distribution; Viral Tropism; Virus Shedding

The present study was an attempt to elucidate the seroprevalence of equine influenza virus (H3N8) in two geographically distinct regions of Pakistan where vaccination is not routinely practiced.. A total number of 315 animals of family Equidae were included in the survey. Blood samples and nasal swabs were collected from the same animal and analyzed through ELISA and Hemagglutination Inhibition.. The seroprevalence for EIV was 10 and 8.39 in districts under study. Out of 29 ELISA positive sera, 7 (24.1 %) showed antibodies against H1 and 22 (75.9 %) showed against H3 of influenza strains. Specie-wise antibody titer against H1 was 7.5 and 9.0 for horses and donkeys, respectively, while mules were negative. Similarly, antibody titer against H3 was 7.12, 6.9, and 6.0 for horses, donkeys, and mules, respectively. No strain was isolated from the nasal swabs despite very high antibody titers of H1 and H3 in the sera of the same animals.. Influenza viruses are circulating in equine species and continuous surveillance is needed to keep check on any future outbreak.

Topics: Animals; Antibodies, Viral; Disease Outbreaks; Enzyme-Linked Immunosorbent Assay; Equidae; Hemagglutination Inhibition Tests; Horse Diseases; Horses; Influenza A Virus, H3N8 Subtype; Nose; Orthomyxoviridae Infections; Pakistan; Seroepidemiologic Studies

We evaluated the sensitivity of PCR on oral fluids in detecting influenza virus in vaccinated and non-vaccinated pigs.. Three-week-old influenza-free pigs were divided into three groups: (i) control, non-vaccinated, (ii) vaccinated with a commercial, heterologous vaccine, and (iii) vaccinated with an experimental, homologous vaccine. After vaccination, an influenza-infected pig was placed in contact with each of the groups. Individual nasal swabs and pen oral fluids were collected daily. Viral RNA was tested for the presence of influenza by RRT-PCR and virus isolation attempted from oral fluids. A pen was considered positive if at least one nasal swab was positive.. Based on nasal swab results, 43·8% of pens were detected positive but only 35% based on oral fluids. Overall sensitivity of oral fluids was 80%, and virus was isolated from 51% of RRT-PCR-positive oral fluids. The kappa coefficient for agreement (ĸ) between oral fluids and nasal swabs was 0·82. Among groups, ĸ was 1 (95% CI, 1-1), 0·74 (95% CI, 0·55-0·92), and 0·76 (95% CI, 0·5-1) for control, heterologous, and homologous-vaccinated groups, respectively. There was less agreement when within pen prevalence was 10% or less. Probability of detecting influenza virus in oral fluids was 99% when within pen prevalence was higher than 18% and decreased to 69% when prevalence was 9%.. Results indicated that pen-based collection of oral fluids is a sensitive method to detect influenza even when within pen prevalence is low and when pigs have been vaccinated and highlight the potential use of oral fluids for influenza surveillance.

Topics: Animals; Influenza A virus; Influenza Vaccines; Molecular Diagnostic Techniques; Nose; Orthomyxoviridae Infections; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Saliva; Sensitivity and Specificity; Swine; Swine Diseases; Veterinary Medicine; Virology

Isolates of the A(H1N1)pdm2009 virus were first identified in asymptomatic swine in Jiangsu province, China in January 2010, indicating that the virus has retro-infected swine after circulating through humans in mainland China. The purpose of this study was to determine whether the avian-origin European H1N1 swine influenza virus (SIV) and the A(H1N1)pdm2009 virus are cocirculating in swine in Jiangsu province of China. From May 2010 to May 2011, 1,030 nasal swab samples were collected from healthy swine in Jiangsu province of China and were tested for influenza A H1N1 using reverse transcription-PCR. Fragments of the complete genomes of viruses from the samples that were positive for influenza A H1N1 were sequenced and analysed. A total of 32 avian-origin European H1N1 SIVs were isolated, and no A(H1N1)pdm2009 viruses were identified; full-length genomes of 18 strains were sequenced. The eight gene segments of some of the isolated H1N1 viruses have 99.1-99.8% sequence identity with the human A/Jiangsu/ALS1/2011(H1N1) isolates in the same region. Our study indicates that the avian-origin European H1N1 SIVs remain endemic in swine and have retro-infected humans after circulating through swine, which may present a risk factor for public health.

Topics: Animals; China; Cluster Analysis; Evolution, Molecular; Genome, Viral; Influenza A Virus, H1N1 Subtype; Molecular Sequence Data; Nose; Orthomyxoviridae Infections; Phylogeny; RNA, Viral; Sequence Analysis, DNA; Swine; Swine Diseases

Annually adjusted inactivated influenza vaccines can prevent infection and limit the spread of seasonal influenza when vaccine strain closely matches circulating strain. For the years when the match is difficult to achieve, a rapid screening of a larger repertoire of vaccines may be required but is difficult to accomplish due to the lack of a convenient small animal model of seasonal influenza vaccines. The goal of this work was to determine whether the cotton rat Sigmodon hispidus, a small laboratory animal susceptible to infection with unadapted influenza viruses, may become such a model. Cotton rats were immunized with a trivalent inactivated vaccine (TIV) FluLaval (2006/2007) and vaccine immunogenicity and antiviral efficacy was evaluated against the homologous H1N1 and a heterologous H3N2 challenge. FluLaval induced a strong virus-specific IgG and neutralizing antibody response against homologous virus, elicited sterilizing immunity in the lungs and significantly reduced viral replication in the nose of infected animals. FluLaval was efficacious in cotton rats as either a single-time or a double immunization, although higher level of protection of the upper respiratory tract was achieved following two doses of vaccine. Antibodies against a heterologous influenza strain were induced in FluLaval-vaccinated animals, but vaccine lacked antiviral efficacy and did not reduce replication of a heterologous virus. Similarity of these findings to human TIV data suggests that the cotton rat may prove to be a reliable small animal model of human influenza vaccines.

Topics: Animals; Antibodies, Neutralizing; Antibodies, Viral; Disease Models, Animal; Immunoglobulin G; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Influenza Vaccines; Lung; Nose; Orthomyxoviridae Infections; Sigmodontinae; Vaccination; Vaccines, Inactivated; Viral Load; Virus Replication

In order to assess the dynamics of influenza virus infection in pigs, serological and virological follow-ups were conducted in two whole batches of pigs from two different farms (F1 and F2), from 3 weeks of age until market age. Anti-swine influenza virus (SIV) antibodies (measured by ELISA and hemagglutination inhibition) and nasal virus shedding (measured by RRT-PCR and isolation in embryonated chicken eggs and MDCK cells) were carried out periodically. SIV isolates were subtyped and hemagglutinin and neuraminidase genes were partially sequenced and analyzed phylogenetically. In F1, four waves of viral circulation were detected, and globally, 62/121 pigs (51.2%) were positive by RRT-PCR at least once. All F1 isolates corresponded to H1N1 subtype although hemagglutination inhibition results also revealed the presence of antibodies against H3N2. The first viral wave took place in the presence of colostral-derived antibodies. Nine pigs were positive in two non-consecutive sampling weeks, with two of the animals being positive with the same isolate. Phylogenetic analyses showed that different H1N1 variants circulated in that farm. In F2, only one isolate, H1N2, was detected and all infections were concentrated in a very short period of time, as assumed for a classic influenza outbreak. These findings led us to propose that influenza virus infection in pigs might present different patterns, from an epidemic outbreak to an endemic form with different waves of infections with a lower incidence.

Topics: Animals; Antibodies, Viral; Dogs; Enzyme-Linked Immunosorbent Assay; Hemagglutination Inhibition Tests; Hemagglutinin Glycoproteins, Influenza Virus; Incidence; Influenza A Virus, H1N1 Subtype; Longitudinal Studies; Madin Darby Canine Kidney Cells; Molecular Sequence Data; Nose; Orthomyxoviridae Infections; Phylogeny; Polymerase Chain Reaction; Seroepidemiologic Studies; Spain; Swine; Swine Diseases; Viral Plaque Assay; Viral Proteins; Virus Shedding

Molecular imaging has gained attention as a possible approach for the study of the progression of inflammation and disease dynamics. Herein we used [(18)F]-2-deoxy-2-fluoro-D-glucose ([(18)F]-FDG) as a radiotracer for PET imaging coupled with CT (FDG-PET/CT) to gain insight into the spatiotemporal progression of the inflammatory response of ferrets infected with a clinical isolate of a pandemic influenza virus, H1N1 (H1N1pdm). The thoracic regions of mock- and H1N1pdm-infected ferrets were imaged prior to infection and at 1, 2, 3 and 6 days post-infection (DPI). On 1 DPI, FDG-PET/CT imaging revealed areas of consolidation in the right caudal lobe which corresponded with elevated [(18)F]-FDG uptake (maximum standardized uptake values (SUVMax), 4.7-7.0). By days 2 and 3, consolidation (CT) and inflammation ([(18)F]-FDG) appeared in the left caudal lobe. By 6 DPI, CT images showed extensive areas of patchy ground-glass opacities (GGO) and consolidations with the largest lesions having high SUVMax (6.0-7.6). Viral shedding and replication were detected in most nasal, throat and rectal swabs and nasal turbinates and lungs on 1, 2 and 3 DPI, but not on day 7, respectively. In conclusion, molecular imaging of infected ferrets revealed a progressive consolidation on CT with corresponding [(18)F]-FDG uptake. Strong positive correlations were measured between SUVMax and bronchiolitis-related pathologic scoring (Spearman's ρ = 0.75). Importantly, the extensive areas of patchy GGO and consolidation seen on CT in the ferret model at 6 DPI are similar to that reported for human H1N1pdm infections. In summary, these first molecular imaging studies of lower respiratory infection with H1N1pdm show that FDG-PET can give insight into the spatiotemporal progression of the inflammation in real-time.

Topics: Animals; Disease Progression; Female; Ferrets; Fluorodeoxyglucose F18; Influenza A Virus, H1N1 Subtype; Lung; Molecular Imaging; Multimodal Imaging; Nose; Orthomyxoviridae Infections; Pandemics; Pneumonia; Positron-Emission Tomography; Tomography, X-Ray Computed; Virus Replication; Virus Shedding

Serum antibodies induced by seasonal influenza or seasonal influenza vaccination exhibit limited or no cross-reactivity against the 2009 pandemic swine-origin influenza virus of the H1N1 subtype (pH1N1). Ferrets immunized once or twice with MF59-adjuvanted seasonal influenza vaccine exhibited significantly reduced lung virus titers but no substantial clinical protection against pH1N1-associated disease. However, priming with MF59-adjuvanted seasonal influenza vaccine significantly increased the efficacy of a pandemic MF59-adjuvanted influenza vaccine against pH1N1 challenge. Elucidating the mechanism involved in this priming principle will contribute to our understanding of vaccine- and infection-induced correlates of protection. Furthermore, a practical consequence of these findings is that during an emerging pandemic, the implementation of a priming strategy with an available adjuvanted seasonal vaccine to precede the eventual pandemic vaccination campaign may be useful and life-saving.

Topics: Adjuvants, Immunologic; Animals; Body Temperature; Body Weight; Disease Models, Animal; Female; Ferrets; Histocytochemistry; Immunization, Secondary; Immunohistochemistry; Influenza A Virus, H1N1 Subtype; Influenza Vaccines; Lung; Male; Microscopy; Nose; Orthomyxoviridae Infections; Pharynx; Polysorbates; Squalene; Vaccination; Viral Load

The gene constellation of the 2009 pandemic A/H1N1 virus is a unique combination from swine influenza A viruses (SIV) of North American and Eurasian lineages, but prior to April 2009 had never before been identified in swine or other species. Although its hemagglutinin gene is related to North American H1 SIV, it is unknown if vaccines currently used in U.S. swine would cross-protect against infection with the pandemic A/H1N1. The objective of this study was to evaluate the efficacy of inactivated vaccines prepared with North American swine influenza viruses as well as an experimental homologous A/H1N1 vaccine to prevent infection and disease from 2009 pandemic A/H1N1. All vaccines tested provided partial protection ranging from reduction of pneumonia lesions to significant reduction in virus replication in the lung and nose. The multivalent vaccines demonstrated partial protection; however, none was able to prevent all nasal shedding or clinical disease. An experimental homologous 2009 A/H1N1 monovalent vaccine provided optimal protection with no virus detected from nose or lung at any time point in addition to amelioration of clinical disease. Based on cross-protection demonstrated with the vaccines evaluated in this study, the U.S. swine herd likely has significant immunity to the 2009 A/H1N1 from prior vaccination or natural exposure. However, consideration should be given for development of monovalent homologous vaccines to best protect the swine population thus limiting shedding and the potential transmission of 2009 A/H1N1 from pigs to people.

Topics: Animals; Cross Protection; Influenza A Virus, H1N1 Subtype; Influenza Vaccines; Lung; Nose; Orthomyxoviridae Infections; Swine; Vaccines, Inactivated; Virus Shedding

Canine influenza virus (CIV) is an emerging pathogen that causes acute respiratory disease in dogs. As with any communicable disease, dog-to-dog transmission of CIV occurs when infected dogs come in contact with other susceptible dogs. We demonstrate that CIV transmission occurs readily from CIV-infected dogs to susceptible dogs following co-mingling. Four experimentally infected dogs were co-mingled with a group of eight CIV-negative dogs at 1 day post-infection and both groups were observed for CIV-associated respiratory disease. The onset of clinical signs, virus shedding, seroconversion, and appearance of lung lesions were observed earlier in experimentally infected dogs; however, the severity of the clinical signs and lung lesions were very similar in both groups. One hundred percent of the experimentally infected dogs and 75% of the contact-exposed dogs excreted virus in their nasal secretions. Additionally, 100% of experimentally infected dogs and 75% of the contact-exposed dogs exhibited varying degrees of pneumonia. Our study results demonstrate that CIV spreads readily from infected dogs to other susceptible dogs through direct contact.

Topics: Animals; Dog Diseases; Dogs; Influenza A Virus, H3N8 Subtype; Lung; Nose; Orthomyxoviridae Infections; Time Factors; Trachea; Virus Shedding

Although pigs are susceptible to avian influenza viruses (AIV) of different subtypes, the incidence of AIV infections in the field appears to be low. Swine H1N1, H3N2 and H1N2 influenza viruses (SIV) are enzootic worldwide and most pigs have antibodies to 1 or more SIV subtypes. This study aimed to examine whether infection-immunity to H1N1 or H3N2 SIV may (1) protect pigs against subsequent infections with AIV of various haemagglutinin and/or neuraminidase subtypes and/or (2) interfere with the serological diagnosis of AIV infection by haemagglutination inhibition (HI) or virus neutralization (VN) tests. Pigs were inoculated intranasally with an H1N1 or H3N2 SIV or left uninoculated. Four or 6 weeks later all pigs were challenged intranasally with 1 of 3 AIV subtypes (H4N6, H5N2 or H7N1). Fifteen out of 17 challenge control pigs shed the respective AIV for 4-6 days post-inoculation and 16 developed HI and VN antibodies. In contrast, 28 of the 29 SIV-immune pigs did not have detectable AIV shedding. Only 12 SIV-immune pigs developed HI antibodies to the AIV used for challenge and 14 had VN antibodies. Antibody titres to the AIV were low in both control and SIV-immune pigs. Our data show that prior infection of pigs with SIV is a barrier to infection with AIV of unrelated subtypes. Serological screening in regions where SIV is enzootic is only useful when the AIV strain for which the pigs need to be tested is known.

Topics: Animals; Antibodies, Viral; Influenza A virus; Nose; Orthomyxoviridae Infections; Random Allocation; Swine; Swine Diseases

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

Chitin in the form of microparticles (chitin microparticles, CMP) has been demonstrated to be a potent stimulator of macrophages, promoting T-helper-1 (Th1) activation and cytokine response. In order to examine the mucosal adjuvant effect of CMP co-administered with influenza hemagglutinin (HA) vaccine against influenza infection, CMP were intranasally co-administered with influenza HA vaccine prepared from PR8 (H1N1) virus. Inoculation of the vaccine with CMP induced primary and secondary anti-HA IgA responses in the nasal wash and anti-HA IgG responses in the serum, which were significantly higher than those of nasal vaccination without CMP, and provided a complete protection against a homologous influenza virus challenge in the nasal infection influenza model. In addition, CMP-based immunization using A/Yamagata (H1N1) and A/Guizhou (H3N2) induced PR8 HA-reactive IgA in the nasal washes and specific-IgG in the serum. The immunization with A/Yamagata and CMP resulted in complete protection against a PR8 (H1N1) challenge in A/Yamagata (H1N1)-vaccinated mice, while that with A/Guizhou (H3N2) and CMP exhibited a 100-fold reduction of nasal virus titer, demonstrating the cross-protective effect of CMP and influenza vaccine. It is suggested that CMP provide a safe and effective adjuvant for nasal vaccination with inactivated influenza vaccine.

Topics: Adjuvants, Immunologic; Administration, Intranasal; Animals; Antibodies, Viral; Chitin; Disease Models, Animal; Female; Hemagglutinin Glycoproteins, Influenza Virus; Immunoglobulin A; Immunoglobulin G; Influenza Vaccines; Mice; Mice, Inbred BALB C; Nose; Orthomyxoviridae Infections; Vaccination

Matix protein 2 (M2) is a transmembrane protein of influenza type A virus. It contains a 23 aa long ectodomain (M2e) that is highly conserved amongst human influenza type A viruses. M2e-specific antibodies have been shown to restrict virus growth in vitro and in vivo and thus have the potential of providing cross-reactive resistance to influenza type A virus infection. We attempted to induce M2e-specific protection with synthetic multiple antigen peptide (MAP) constructs that contained covalently linked M2e- and Th-determinant peptides. Mice, vaccinated twice by the intranasal (i.n.) route with adjuvanted M2e-MAPs exhibited significant resistance to virus replication in all sites of the respiratory tract. Compared to mice primed by two consecutive heterosubtypic infections, resistance was of similar strength in nasal and tracheal tissue but lower in pulmonary tissue. Importantly, the protection in M2e-MAP- and infection-immunized mice appeared to be mediated by distinct immune mechanisms. This suggests that stronger protection may be achievable by combining both protective activities.

Topics: Amino Acid Sequence; Animals; Antibodies, Viral; Antibody Formation; CD4-Positive T-Lymphocytes; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Immunity, Innate; Influenza A virus; Influenza Vaccines; Lung; Lymphocyte Activation; Mice; Molecular Sequence Data; Nose; Orthomyxoviridae Infections; Protein Structure, Secondary; Time Factors; Vaccines, Synthetic; Viral Matrix Proteins

Serologic and virologic prevalence of infection with different swine influenza virus (SIV) subtypes was investigated using swine sera, nasal swabs and lung samples that had been submitted for a diagnosis to the Minnesota Veterinary Diagnostic Laboratory. A total of 111,418 pig sera were tested for SIV antibody between 1998 and 2000, and 25,348 sera (22.8%) were found to be positive by the hemagglutination inhibition (HI) test. Of the positive samples, 16,807 (66.7%) and 8,541 (33.7%) had antibody to H1 and H3 subtypes, respectively. Between January 1998 and May of 2001, a total of 3,561 nasal swabs or lung samples were examined for the presence of SIV, and SIV was isolated from 1,124 samples (31.7%). Of these isolates, 869 (77.3%) and 255 (22.7%) were subtyped as H1 and H3, respectively, by the HI method. For further characterization, 120 SIV isolates each from 1998 to 2001 were randomly selected from a culture collection and their hemagglutinin (HA) and neuraminidase genes examined by reverse transcription-PCR and sequencing. Of the 480 isolates, 322 (67.1%), 22 (4.6%) and 129 (26.9%) were subtyped as H1N1, H1N2 and H3N2, respectively. The remaining 7 samples (1.5%) were found to contain both H1N1 and H3N2 viruses. The SIV H1N2 subtype was isolated from 1, 8, and 13 samples in 1999, 2000, and 2001, respectively. The 22 H1N2 isolates originated from 9 different states of the United States. Genetic screening of the HA genes of 12 selected H1N2 isolates showed that 8 of them had a close phylogenetic relationship with the Indiana isolate of H1N2 (A/Swine/Indiana/9K035/99), while 4 isolates were closely related to classical SIV H1N1.

Topics: Amino Acid Sequence; Animal Husbandry; Animals; Antibodies, Viral; Hemagglutination Inhibition Tests; Hemagglutinin Glycoproteins, Influenza Virus; Influenza A virus; Lung; Molecular Sequence Data; Nose; Orthomyxoviridae Infections; Phylogeny; Prevalence; Reverse Transcriptase Polymerase Chain Reaction; Sequence Alignment; Sequence Analysis, DNA; Swine Diseases; United States

Topics: Aging; Animals; Behavior, Animal; Cognition; Female; Male; Nose; Orthomyxoviridae Infections; Pan troglodytes; Primate Diseases; Self Care; Tanzania

The effects of serum antibody on the replication of influenza C virus in the nose and lung were evaluated in rats challenged with the virus by the intranasal and endotracheal routes, respectively. Convalescent rat serum administered intraperitoneally prior to infection suppressed virus replication significantly in both the nasal and pulmonary tissues. Resistance achieved was however much greater in the lung than in the nose. Rats with a serum neutralizing antibody titer of 1:800 showed almost complete resistance to pulmonary virus infection, and virus yield from the lung was reduced 10- to 100-fold in animals with the antibody titer of 1:80-160 or less. In contrast, significant decrease in virus shedding from the nose was observed only in animals with a serum antibody titer of 1:800 or greater. The effect of adoptive transfer of monoclonal antibodies (MAbs) to haemagglutinin-esterase (HE) glycoprotein and matrix (M) protein on pulmonary virus replication was also examined. Anti-HE MAbs with neutralization activity prevented virus shedding from the lung almost completely whereas non-neutralizing anti-HE MAb and anti-M Mab showed no inhibitory effect.

Topics: Animals; Antibodies, Monoclonal; Antibodies, Viral; Female; Gammainfluenzavirus; Hemagglutinins, Viral; Immunization, Passive; Lung; Male; Neutralization Tests; Nose; Orthomyxoviridae Infections; Rats; Viral Fusion Proteins; Viral Matrix Proteins; Viral Proteins; Virus Replication

Infant guinea-pigs born to mothers immunized against influenza virus by infection during pregnancy were reared from birth by non-immune foster mothers. As a control for the effects of fostering, a similar group were fostered to immune mothers. Fostering, regardless of the immune state of the foster-mother, increased the susceptibility of the infant to upper respiratory tract infection. Increased susceptibility was associated with ablation of the infants IgM and IgA antibody responses and reduced secretion of transplacentally acquired IgG antibody in nasal secretions. In the reciprocal experiment, infants of non-immune mothers fostered to immune mothers cleared virus more rapidly than their peers who were fed by their own mothers. This protective effect was associated with an enhanced nasal IgM and IgA antibody response. Infants of immune mothers separated from their mothers at birth and hand-reared on a cow's-milk-based formula feed suffered an increased susceptibility to the virus similar to that seen in fostered infants. Addition of a pool of expressed milk from a group of immune mothers, including their own, to the feed of hand-reared infants did not reduce their susceptibility. However, a further group of infants fed a non-cellular whey fraction of the same milk pool secreted significantly lower titres of virus. This increased protection was associated with elevated levels of IgG antibody secretion into nasal washes early in infection.

Topics: Animal Nutritional Physiological Phenomena; Animals; Bottle Feeding; Disease Susceptibility; Guinea Pigs; Immunoglobulins; Nose; Orthomyxoviridae Infections

BALB/c normal and nude mice were infected with a non-lethal mouse-passaged A/PC/1/73 (H3N2) influenza virus in order to assess the role of T cells on the course of disease of the nose, trachea and lung. The tracheal epithelium of both mouse strains was desquamated by 3 days after infection. Although normal regeneration began, nude mice never completed that regeneration whereas normal mice had fully regenerated tracheas by Day 14. This failure to complete the recovery was also evident from the continued virus shedding by the nude mouse. In order to assess the role of serum antibody on recovery from infection, ferret, goat or mouse antibody to H3N2 influenza virus was passively administered to nude mice after infection. It resulted in a transient decrease in virus shedding from the nose, trachea and lung, and complete but temporary regeneration of the tracheal epithelium. However, later in the course of the infection, when serum antibody levels were no longer detectable, the tracheal epithelium of these animals redesquamated and large amounts of virus were again shed from nose, trachea and lungs. We conclude that: (i) desquamation of the ciliated epithelium of the trachea is not T-cell dependent; and (ii) serum antibody can contribute to temporary recovery from infection, but by itself is insufficient for permanent recovery of the nose, trachea or lung.

Topics: Animals; Ferrets; Goats; Immunization, Passive; Influenza A virus; Lung; Mice; Mice, Inbred BALB C; Mice, Nude; Microscopy, Electron, Scanning; Nose; Orthomyxoviridae Infections; Trachea

Previous work has shown that fever in influenza of ferrets occurs following release of endogenous pyrogen from virus-phagocyte interaction in the upper respiratory tract (URT), and suggested that the poor inflammatory response and correspondingly low fever elicited by A/Puerto Rico/8/34 (H1N1), compared with H3N2 reassortant clones of A/Puerto Rico/8/34-A/England/939/69, were related to its H1 and N1 surface antigens. Nasal virus levels, inflammatory and pyrexial responses produced in ferrets by clones 31 (H3N1) and 64b (H1N2) of the same reassortant system suggested a connection between the H1 antigen and low inflammatory response, but results were not conclusive. Unlike A/Puerto Rico/8/34, two recent H1N1 isolates, A/USSR/90/77 and A/Fiji/15899/83, produced a high inflammatory response yet low fever despite large amounts of virus in the URT, suggesting that either no connection exists between the acquisition of the H1 antigen and production of a low inflammatory response, or the H1 antigen of recent isolates, whilst antigenically related to that of A/Puerto Rico/8/34, is biologically different.

Topics: Animals; Antigens, Surface; Antigens, Viral; Ferrets; Fever; Inflammation; Influenza A virus; Male; Nose; Orthomyxoviridae Infections

The immunogenicity of influenza A strain A/Northern Territory/60/68 for CSL mice when delivered by the ocular, nasal and subcutaneous routes was determined according to the median protective dose, PD50, i.e. the dose of infectious virus required to induce inhibition of multiplication of a standard intranasal challenge dose of 10(4.5) median tissue-culture-infectious doses (TCID50) of homologous virus three weeks after vaccination (PD50). For mice inoculated by the ocular route, an immunizing dose of 10(2.89) TCID50 per animal was required. For anaesthetized mice vaccinated intranasally and unanaesthetized mice vaccinated subcutaneously these figures are less than 10(2.00) and greater than 10(6.00) TCID50 per animal, respectively. The lower immunogenicity of virus delivered by the ocular route compared with the intranasal route can be correlated with a lowered capacity of ocularly administered virus to replicate in the murine respiratory tract. The immunogenicity of A/Ann Arbor/6/60-ca administered in two identical doses, was also determined for (a) the intraocular route, (b) the intranasal route with anaesthetized animals and (c) the intranasal route with unanaesthetized animals, using the parental A/Ann Arbor/6/60 as the challenge virus. Two doses were required because ca viruses have been shown to be poor immunogens in the same animal model. The PD50 for the ocular route was 10(2.83) TCID50 per animal compared with 10(2.71) for the intranasal route using unanaesthetized animals and 10(1.36) for the intranasal route using anaesthetized animals. Administration of living attenuated vaccine viruses by the ocular route is thus an effective means of inducing immunity to influenza viruses in the respiratory tract of mice.

Topics: Animals; Antibodies, Viral; Eye; Immunization; Influenza Vaccines; Mice; Nose; Orthomyxoviridae Infections; Respiratory System; Vaccines, Attenuated

From 6 experiments in which 99 ferrets were infected with influenza virus A/Finland/74 and treated with various agents which suppress virus shedding and other parameters of infection, we assessed whether rectal temperature correlated with nasal virus shedding. A number of temperature and virus-shedding related parameters were determined for each experiment but statistical analysis showed little correlation between them, although an elevated temperature occurred at some time after infection. The pooled data also suggested that temperature and virus shedding parameters are not clearly related. The analysis indicates that intermittent rectal temperature measurements are unsatisfactory for determining the efficacy of anti-influenza agents in ferrets.

Topics: Animals; Antiviral Agents; Body Temperature; Ferrets; Influenza A virus; Male; Nose; Orthomyxoviridae Infections

Immunization by live influenza virus induced a greater protective effect against subsequent challenge by the homologous virus than by the corresponding killed virus vaccine. Furthermore, tracheas excised from 11-day and 28-day influenza-virus-infected ferrets were more resistant to reinfection than tracheas excised from ferrets immunized by killed influenza vaccine, despite equivalent serum antibody titres at these times. Histological examination of trachea sections taken from vaccinated and virus-infected animals showed an increased cellular inflammatory infiltrate in the latter at Days 11 and 28 after immunization. The amount of IgG detected in these sections, measured by a fluorescent antibody technique, correlated with the extent of cellular infiltration, the fluorescence being both intra- and extracellular for sections from virus-infected animals, but only extracellular in sections from Day-28 vaccinated animals. In contrast there was little or no cellular infiltration into lung tissues, the levels of IgG detected being comparable to those in sections taken from control animals. These results provide further evidence that live influenza vaccines induce local antibody in the upper respiratory tract of ferrets, in contrast to killed influenza vaccines, and that this local induction may play a significant role in the greater protective efficacy of live influenza vaccines.

Topics: Animals; Antibodies, Viral; Body Temperature; Ferrets; Fluorescent Antibody Technique; Hemagglutination Inhibition Tests; Immunoglobulin G; Influenza A virus; Influenza Vaccines; Lung; Nose; Organ Culture Techniques; Orthomyxoviridae Infections; Trachea

To establish whether immunity to influenza infection in the ferret is local or systemic, two sites of challenge were utilized: the nose and the anatomically isolated tracheal pouch. Infection of either site did not spread to the other site, and challenge of either site resulted in seroconversion by 13 days. Simultaneous challenge of both sites 21 days after the primary infection revealed that prior infection of the pouch prevented subsequent reinfection of the pouch, but not infection of the nose. Thus, systemic immunity did not prevent the initiation of nasal influenza infection in the ferret. However, the duration of virus shedding from the nose was reduced to half of that seen when ferrets were infected for the first time, showing that the prior pouch infection did lead to a more rapid recovery from the subsequent nasal infection. Passively administered anti-influenza antibody did not prevent or modify the nasal infection, but it did prevent the pouch infection. This is consistent with the observation that an initial infection of the nose prevented pouch infection upon challenge 21 days later. The prior nasal infection also prevented the subsequent nasal infection. These data suggest that immunity to acquisition of influenza infection in the ferret is a local phenomenon, whereas recovery from active infection is influenced by systemic immune mechanisms.

Topics: Animals; Antibodies, Viral; Ferrets; Immune Sera; Immunity; Immunization; Influenza A virus; Male; Nose; Orthomyxoviridae Infections; Trachea

Topics: Animals; Carnivora; Cell Count; Ferrets; Fever; Inflammation; Nose; Orthomyxoviridae; Orthomyxoviridae Infections; Virulence

Antibody-mediated immune suppression occurred when newborn pigs with naturally acquired passive antibody were exposed to seine influenza virus. Frequency and relative ease of recovery of virus from nasal secretions were inversely related to the concentration of specific passive antibody existing at time of exposure. Severe overt respiratory signs during the acute stages of the disease were observed only in pigs with low passive antibody concentrations. The concentration of passive antibody at the time of exposure determined the immune status of the pig during the convalescent stage of disease. Infection could occur in the presence of high passive antibody concentrations, but the pig was not immunologically stimulated. Reexposure after the decay of passive antibody produced primary immune respone, severe clinical reinfection, and recovery of virus from nasal secretions for a period of time similar to that seen in pigs having their first exposure. Infection of newborn pigs with low passive antibody concentrations led to immunologic priming. A second exposure to virus produced a secondary immune response, mild clinical disease, and shortened time during which virus was recovered from nasal secretions. The relevance of these studies for the practice of vaccination or infections of the dam before parturition so that the neonate will have specific passive immunity is discussed.

Topics: Aerosols; Animals; Animals, Newborn; Antibody Formation; Antigen-Antibody Reactions; Antigens, Viral; Colostrum; Female; Hemagglutination Inhibition Tests; Immunization, Passive; Immunosuppression Therapy; Influenza Vaccines; Nose; Orthomyxoviridae; Orthomyxoviridae Infections; Specific Pathogen-Free Organisms; Swine; Swine Diseases; Vaccination

The role of viruses and M. pneumoniae in episodes of acute respiratory illness in childhood has been studied in a London general practice. The total isolation rate was 31-7 per cent, but the rate varied from 32-6 per cent in upper respiratory infections to 64-0 per cent in pneumonia. The clinical features associated with infection were influenced not only by the type of agent but also by age and other host factors in infected children. Rhinoviruses were more commonly isolated than any other agent and were frequently associated with wheezy bronchitis.

Topics: Adenoviridae; Child; Child, Preschool; Enterovirus; Female; Humans; Infant; Infant, Newborn; London; Male; Mycoplasma; Mycoplasma Infections; Nose; Orthomyxoviridae; Orthomyxoviridae Infections; Paramyxoviridae; Pharynx; Respiratory Tract Infections; Rhinovirus; Simplexvirus; Virus Cultivation; Virus Diseases; Viruses

Five Iowa swine herds (involving about 7,000 swine) were placed under surveillance for signs of influenza-like illness. Blood samples for hemagglutination-inhibition (HI) tests of serums and nasal secretions on swabs for viral isolation were collected from 20 feeder swine in each herd at the outset of surveillance. On the basis of results of HI tests, 6 swine in each herd tested were chosen to be resampled 6 weeks after the first blood sample was collected if swine influenza virus (SIV) was not isolated, but 3 weeks after the first blood sample was collected if SIV was isolated at the outset of surveillance. The swine chosen for resampling were considered sentinels in a herd for the duration of surveillance. Swine influenza virus was isolated from 20 of 20 swine in each of 2 herds that had signs of influenza-like illness. The initial HI titer of each of the 20 swine in the 2 herds was less than 10. However, serum samples prepared from blood collected from sentinel swine in the 2 herds 3 weeks after isolation of SIV had HI geometric mean titers (GMT) of 23 and 34. One herd had an initial HI GMT of 21. A SIV was not isolated from this herd, and serum samples obtained from 3 of the 6 sentinel seine 6 weeks after the first blood sample was collected still had demonstrable HI antibody.

Topics: Animals; Chick Embryo; Iowa; Nose; Orthomyxoviridae; Orthomyxoviridae Infections; Swine; Swine Diseases

Ferrets were vaccinated with either A/England/42/72 zonal purified influenza queous vaccine containing whole virus particles, or a subunit vaccine containing the purified hemagglutinin and neura-minidase proteins of A/England/42/72 adsorbed onto aluminium hydroxide. The immune status of the ferrets was assessed by reaction to challenge with virulent live virus of the homologous strain. In the preliminary experiment reported, the subunit vaccine conferred greater protection than the zonal purified vaccine.

Topics: Animals; Antibodies, Viral; Antigens, Viral; Body Temperature; Female; Ferrets; Hemagglutination Inhibition Tests; Hemagglutinins, Viral; Influenza Vaccines; Neuraminidase; Neutralization Tests; Nose; Orthomyxoviridae; Orthomyxoviridae Infections; Vaccination

The antibody response and immunity to challenge infection were determined in ferrets immunized with inactivated influenza vaccine in saline or adjuvant. Adjuvanated vaccines induced variable titres of serum antibody, and the degree of immunity to challenge infection was directly related to the titre of serum HI antibody induced by these vaccines. Conventional doses of saline vaccine did not induce serum HI antibody, and the ferrets were completely susceptible to challenge infection. Infection with live virus produced a more solid immunity to challenge infection than immunization with a adjuvant vaccines, even though immunization induced higher titres of serum HI antibody. Ferrets previously infected with a heterotypic influenza A virus, but not other viruses, produced serum HI antibody in response to subsequent immunization with inactivated influenza vaccine. Similar results were obtained in hamsters and mice. Thus, the failure of animals to produce antibody in response to immunization with saline inactivated vaccines was due to the absence of a previous priming infection; this prior experience would be a feature of most volunteers. Live virus infection produced nasal antibody in ferrets, but inactivated vaccines only induced serum antibody. This may explain the more solid immunity observed following infection; however, at the time of challenge infection, no nasal wash antibody could be detected. Immunization with inactivated vaccine in Freund's complete adjuvant and influenza virus infection both produced a cell-mediated immune response; thus, the difference in the degree of immunity induced by these two immunization procedures are probably not due to differences in the cell-mediated immune response. However, cell-mediated immunity was measured by skin tests and by macrophage migration inhibition tests with spleen cells; the reaction of cells from the respiratory tract may be more important, but was not measured in these studies.

Topics: Administration, Intranasal; Animals; Antibodies, Viral; Antigens, Viral; Cricetinae; Disease Models, Animal; Ferrets; Hemagglutination Inhibition Tests; Immunity; Immunity, Cellular; Immunoelectrophoresis; Immunoglobulin G; Influenza Vaccines; Mice; Neutralization Tests; Nose; Orthomyxoviridae; Orthomyxoviridae Infections; Recurrence; Serum Albumin; Vaccination

Rhesus monkeys (Macaca mulatta) exposed to small-particle aerosols of the Aichi strain of type A2 influenza virus responded by shedding virus from the nasopharynx for 7 to 9 days and by seroconversion (hemagglutination inhibition) 8 or 9 days after exposure. After rechallenge with the homologous virus, no replication of the organism was observed, and a serological anamnestic reaction occurred. The data indicate that the rhesus monkey is a useful primate model for evaluating induced immunity to influenza virus infection.

Topics: Aerosols; Animals; Disease Models, Animal; Erythrocytes; Guinea Pigs; Haplorhini; Hemagglutination Inhibition Tests; Immunization, Secondary; Immunodiffusion; Immunoglobulin A; Macaca; Mucus; Nose; Orthomyxoviridae; Orthomyxoviridae Infections; Pharynx

Topics: Airway Resistance; Animals; Aspirin; Carnivora; Nasal Decongestants; Nose; Orthomyxoviridae Infections; Placebos

Topics: Adenocarcinoma; Animals; Bronchial Neoplasms; Carcinoma, Squamous Cell; Mice; Mice, Inbred Strains; Neoplasms, Experimental; Nose; Orthomyxoviridae; Orthomyxoviridae Infections

Topics: Adenoviridae; Adenoviridae Infections; Animals; Haplorhini; Hemagglutination Inhibition Tests; Monkey Diseases; Neutralization Tests; Nose; Orthomyxoviridae Infections; Paramyxoviridae; Pharynx; Respiratory Tract Infections; Rhinovirus; Time Factors; Virus Diseases

Topics: Adenoviridae; Adenoviridae Infections; Cells, Cultured; Child; Child, Preschool; Enterovirus; Enterovirus Infections; Feces; Gastrointestinal Diseases; Herpesviridae; Herpesviridae Infections; Humans; Infant; Microbial Sensitivity Tests; Nose; Orthomyxoviridae; Orthomyxoviridae Infections; Pharynx; Population Surveillance; Respiratory Tract Infections; Rhinovirus; Virus Cultivation; Virus Diseases; Viruses; Washington

Topics: Adolescent; Adult; Animals; Bacterial Infections; Cell Line; Cells, Cultured; Child; Child, Preschool; Culture Techniques; Cytopathogenic Effect, Viral; Diagnosis, Differential; Female; Haplorhini; HeLa Cells; Humans; Kidney; Lung; Male; Nose; Orthomyxoviridae Infections; Pharynx; Respiratory Syncytial Viruses; Respiratory Tract Infections; Sex Factors; Virus Cultivation; Virus Diseases

Topics: Adaptation, Physiological; Administration, Oral; Adolescent; Aerosols; Age Factors; Antibodies; Child; Child, Preschool; Cold Temperature; Complement Fixation Tests; Cytopathogenic Effect, Viral; Humans; Immunity, Active; Immunodiffusion; Infant; Mucus; Neutralization Tests; Nose; Orthomyxoviridae Infections; Respiratory Syncytial Viruses; Respiratory Tract Infections; Vaccination; Viral Vaccines; Virulence

Topics: Animals; Antibodies; Bird Diseases; Birds; Carrier State; Chick Embryo; Female; Hemagglutination Inhibition Tests; Immune Sera; Injections, Intramuscular; Injections, Intravenous; Nose; Orthomyxoviridae; Orthomyxoviridae Infections; Ovum; Poultry Diseases; Trachea; Turkeys

Topics: Age Factors; Animals; Cattle; Cattle Diseases; Complement Fixation Tests; Conjunctiva; Culture Techniques; Cytopathogenic Effect, Viral; Female; Filtration; Fluorescent Antibody Technique; Neutralization Tests; Nose; Orthomyxoviridae Infections; Respiratory Syncytial Viruses; Respiratory Tract Infections; Staining and Labeling; Switzerland

Topics: Animals; Antigens; Carcinoma; Cell Line; Child; Child, Preschool; Culture Techniques; Cytodiagnosis; Cytopathogenic Effect, Viral; Fluorescent Antibody Technique; Haplorhini; Humans; Infant; Kidney; Laryngeal Neoplasms; Lung; Methods; Nose; Orthomyxoviridae Infections; Pharynx; Respiratory Syncytial Viruses; Respiratory Tract Infections; Virus Cultivation

Topics: Animals; Antibodies; Blood Sedimentation; Carnivora; Fever; Interferons; Leukocyte Count; Male; Nasal Mucosa; Nose; Orthomyxoviridae Infections; Respiratory Syncytial Viruses; Rhinitis; Virus Replication

Topics: Acids; Aldehydes; Animals; Bronchi; Carcinogens; Epithelium; Hyperplasia; Infections; Lung; Male; Metaplasia; Mice; Nasal Mucosa; Nitrogen Dioxide; Nose; Orthomyxoviridae Infections; Respiratory System; Smoking; Trachea

Topics: Animals; Immune Sera; Lung; Male; Neutralization Tests; Nose; Orthomyxoviridae Infections; Pasteurella; Respiratory Tract Infections; Respirovirus; Sheep; Sheep Diseases

Topics: Adolescent; Adult; Child; Child, Preschool; Complement Fixation Tests; Female; Humans; Infant; Male; Nose; Orthomyxoviridae Infections; Pharynx; Respiratory Syncytial Viruses; Respiratory Tract Infections; Trinidad and Tobago

Topics: Animals; Antibodies; Complement Fixation Tests; Female; Hemagglutination Inhibition Tests; Lung; Male; Mice; Neutralization Tests; Nose; Orthomyxoviridae Infections; Parainfluenza Virus 1, Human; Paramyxoviridae Infections

Topics: Animals; Carnivora; Models, Theoretical; Nose; Orthomyxoviridae Infections; Rhinitis

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: 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