exudates and Zika-Virus-Infection

Emerging arboviruses such as chikungunya and Zika viruses have unexpectedly caused widespread outbreaks in tropical and subtropical regions recently. Ross River virus (RRV) is endemic in Australia and has epidemic potential. In Malaysia, Aedes mosquitoes are abundant and drive dengue and chikungunya outbreaks. We assessed risk of an RRV outbreak in Kuala Lumpur, Malaysia by determining vector competence of local Aedes mosquitoes and local seroprevalence as a proxy of human population susceptibility.. We assessed oral susceptibility of Malaysian Ae. aegypti and Ae. albopictus by real-time PCR to an Australian RRV strain SW2089. Replication kinetics in midgut, head and saliva were determined at 3 and 10 days post-infection (dpi). With a 3 log10 PFU/ml blood meal, infection rate was higher in Ae. albopictus (60%) than Ae. aegypti (15%; p<0.05). Despite similar infection rates at 5 and 7 log10 PFU/ml blood meals, Ae. albopictus had significantly higher viral loads and required a significantly lower median oral infectious dose (2.7 log10 PFU/ml) than Ae. aegypti (4.2 log10 PFU/ml). Ae. albopictus showed higher vector competence, with higher viral loads in heads and saliva, and higher transmission rate (RRV present in saliva) of 100% at 10 dpi, than Ae. aegypti (41%). Ae. aegypti demonstrated greater barriers at either midgut escape or salivary gland infection, and salivary gland escape. We then assessed seropositivity against RRV among 240 Kuala Lumpur inpatients using plaque reduction neutralization, and found a low rate of 0.8%.. Both Ae. aegypti and Ae. albopictus are susceptible to RRV, but Ae. albopictus displays greater vector competence. Extensive travel links with Australia, abundant Aedes vectors, and low population immunity places Kuala Lumpur, Malaysia at risk of an imported RRV outbreak. Surveillance and increased diagnostic awareness and capacity are imperative to prevent establishment of new arboviruses in Malaysia.

Topics: Aedes; Animals; Arboviruses; Australia; Chikungunya Fever; Humans; Malaysia; Mosquito Vectors; Ross River virus; Seroepidemiologic Studies; Zika Virus; Zika Virus Infection

Dengue is widespread globally, but it is more severe in hyperendemic regions where the virus, its vectors, and its human hosts naturally occur. The problem is particularly acute in cities, where outbreaks affect a large human population living in a wide array of socio-environmental conditions. Controlling outbreaks will rely largely on systematic data collection and analysis approaches to uncover nuances on a city-by-city basis due to the diversity of factors.. The main objective of this study is to consolidate and analyse the dengue case dataset amassed by the e-Dengue web-based information system, developed by the Ministry of Health Malaysia, to improve our epidemiological understanding.. We retrieved data from the e-Dengue system and integrated a total of 18,812 cases from 2012 to 2019 (8 years) with meteorological data, geoinformatics techniques, and socio-environmental observations to identify plausible factors that could have caused dengue outbreaks in Ipoh, a hyperendemic city in Malaysia.. The rainfall trend characterised by a linearity of R. Our work demonstrates the novelty of the e-Dengue system, which can identify outbreak factors at high resolution when integrated with non-medical fields. Besides dengue, the techniques and insights laid out in this paper are valuable, at large, for advancing control strategies for other mosquito-borne diseases such as malaria, chikungunya, and zika in other hyperendemic cities elsewhere globally.

Topics: Animals; Cities; Dengue; Disease Outbreaks; Humans; Information Systems; Malaysia; Zika Virus; Zika Virus Infection

The aim of this study was to analyze the prevention and control practices against Zika virus (ZIKV) infection among pregnant women in Malaysia. A cross-sectional study was conducted among pregnant women who received antenatal care. Only 7.8% reported that they abstained from sex or used barrier methods during sexual intercourse to prevent ZIKV transmission. The odds of abstaining from sex or using barrier methods were significantly higher among the Chinese ethnic group than the Malay ethnic group (odds ratio [OR] = 4.569; 95% confidence interval [CI]: 2.696-7.743). A total ZIKV knowledge score of 12-24 was also significantly associated with higher odds of abstaining from sex or using barrier methods than a score of 0-11 (OR = 2.819; 95% CI: 1.682-4.725). In total, 38.6% of women had a higher mean total score for all the current mosquito control practices than they did before hearing of ZIKV. Participants living in bungalows or village houses (OR = 2.006; 95% CI: 1.023-3.936) and low-rise houses (OR = 1.566; 95% CI: 1.109-2.212) were more likely to have a higher mean total score of current mosquito control practices than the practices before hearing of ZIKV compared to those in high-rise houses. The lack of ZIKV knowledge and control practices provides insight for the pre-emptive and prompt development of health education systems for pregnant women during antenatal care visits.

Topics: Cross-Sectional Studies; Dengue; Female; Humans; Malaysia; Pregnancy; Pregnant Women; Zika Virus; Zika Virus Infection

The aim of this study is to assess knowledge and attitudes toward Zika virus disease (ZVD) as well as mosquito prevention practices in Malaysia at a nationwide level.. Computer-assisted telephone interviews (CATI) were conducted between June 2019 and February 2020.. There are gaps in knowledge about the symptoms, mode of transmission, and risk of microcephaly. The mean for the Zika-related knowledge score was 5.9 (SD ± 4.4) out of a possible score of 14. The majority perceived. Zika prevention measures should be targeted in priority toward residents in lower socioeconomic neighborhoods. Campaigns should focus on messages highlighting the high risk of getting dengue.

Topics: Dengue; Health Knowledge, Attitudes, Practice; Humans; Malaysia; Zika Virus; Zika Virus Infection

Several Zika virus (ZIKV) seroprevalence studies have been conducted in Africa, Asia, Oceania, the Americas, and the Caribbean. However, studies on ZIKV seroprevalence are limited in Malaysia though several studies have shown that the disease is endemic in the Malaysian state of Sabah. To evaluate the seroprevalence of ZIKV infection, 818 serum samples were collected from febrile patients and healthy blood donors from the Kudat and Kota Kinabalu districts in Sabah from 2017 to 2018. They were screened for ZIKV infection by IgM and IgG ELISA, and positive ZIKV IgM samples were subjected to a 90% neutralization test for confirmation. Twenty-four (6% [95% CI 4 to 8]) confirmed and two (0.5% [95% CI 0.13 to 1.8]) probable ZIKV infections were detected among 400 febrile illness patients. Of 418 healthy blood donor samples, six (1.4% [95% CI 0.65 to 3]) were determined as confirmed ZIKV infections and six (1.4% [95% CI 0.65 to 3]) indicated probable ZIKV infection. This is the first study on the seroprevalence of ZIKV infections among patients and healthy blood donors in Sabah. Compared with previous studies in Malaysia, this study shows that the incidence of ZIKV infection has increased. It also suggests that a sero-surveillance system is essential to determine the circulation of ZIKV in Sabah, Malaysia.

Topics: Adolescent; Adult; Antibodies, Viral; Blood Donors; Borneo; Child; Child, Preschool; Female; Fever; Humans; Immunoglobulin G; Infant; Malaysia; Male; Middle Aged; Neutralization Tests; Seroepidemiologic Studies; Young Adult; Zika Virus; Zika Virus Infection

The recommended test guidelines for Zika virus (ZIKV) include using both molecular and serological tools. While the molecular tools are useful for detecting acute infection, the serological tools are useful for the detection of previous infections. Nevertheless, detection of ZIKV-specific antibodies remains a challenge due to the high cross-reactivity between ZIKV and other flaviviruses such as dengue virus (DENV) and Japanese encephalitis virus (JEV). The objective of this study is to evaluate the commercially available enzyme-linked immunosorbent assay (ELISA) for the detection of ZIKV IgG. In this study, we evaluated 6 commercially available anti-ZIKV IgG ELISA kits. Pre-characterized serum panels consisting of 70 sera were selected for the evaluation. The diagnostic accuracy of each ELISA kits was determined and compared to the gold standard, Foci Reduction Neutralization Test (FRNT). The present study established that the performance of the NS1-based anti-ZIKV IgG ELISA kit was superior to that which uses of the E protein as antigen. Overall, commercial ZIKV IgG ELISA showed varying test performances, with some achieving moderate to high test sensitivities and specificities. When compared against the FRNT, the test sensitivities ranged from 7.1% to 78.6%, whereas, the test specificities ranged from 40.0% to 100%. Limitation to the study includes the cross reactivity between flavivirus and specificity of the kit in addressing the cross reactivity.

Topics: Antibodies, Viral; Cross Reactions; Enzyme-Linked Immunosorbent Assay; Humans; Immunoglobulin G; Malaysia; Sensitivity and Specificity; Serologic Tests; Zika Virus; Zika Virus Infection

Topics: Chikungunya Fever; Dengue; Humans; Malaysia; Zika Virus; Zika Virus Infection

Dengue virus (DENV), Japanese encephalitis virus (JEV), and Zika virus (ZIKV) are mosquito-borne flavivirus of medical importance in tropical countries such as Malaysia. However, much remains unknown regarding their prevalence among the underserved indigenous people (Orang Asli) living in communities in the forest fringe areas of Peninsular Malaysia. Information on the prevalence of diseases is necessary to elevate the effectiveness of disease control and preventive measures. This study aimed to determine the seroprevalence of the three major flaviviruses among the Orang Asli and investigate the association between demographic factors and seropositivities. Sampling activities were conducted in the Orang Asli villages to obtain serum samples and demographic data from consenting volunteers. The presence of DENV, JEV, and ZIKV immunoglobulin G (IgG) antibodies in the sera were examined using commercial enzyme-linked immunosorbent assay kits. A focus reduction neutralization assay was performed to measure virus-specific neutralizing antibodies. A total of 872 serum samples were obtained from the Orang Asli volunteers. Serological assay results revealed that DENV IgG, JEV IgG, and ZIKV IgG seropositivities among the Orang Asli were at 4.9%, 48.4%, and 13.2%, respectively. Neutralizing antibodies (FRNT50 ≥ 1:40) against JEV and ZIKV were found in 86.7% and 100.0%, respectively, out of the samples tested. Positive serology to all three viruses corresponded significantly to the age of the volunteers with increasing seropositivity in older volunteers. Findings from the study suggest that Orang Asli are at significant risk of contracting JEV and ZIKV infections despite the lack of active transmission of the viruses in the country.

Topics: Adult; Antibodies, Neutralizing; Antibodies, Viral; Cross Reactions; Dengue; Dengue Virus; Encephalitis Virus, Japanese; Encephalitis, Japanese; Enzyme-Linked Immunosorbent Assay; Female; Flavivirus; Humans; Immunoglobulin G; Indigenous Peoples; Malaysia; Male; Seroepidemiologic Studies; Young Adult; Zika Virus; Zika Virus Infection

Two confirmed human cases of Zika virus (ZIKV) were reported in the district of Miri, Sarawak, in 2016. Following that, a mosquito-based ZIKV surveillance study was conducted within 200-m radius from the case houses. Mosquito surveillance was conducted using five different methods, that is, biogents sentinel mosquito (BG) sentinel trap, modified sticky ovitrap, resting catch, larval surveillance, and conventional ovitrap. A total of 527 and 390 mosquito samples were obtained from the case houses in two localities, namely, Kampung Lopeng and Taman Shang Ri La, Miri, Sarawak, respectively. All mosquitoes collected were identified, which consisted of 11 species.

Topics: Aedes; Animals; Culex; Culicidae; Female; Humans; Malaysia; Male; Mosquito Vectors; Population Surveillance; Real-Time Polymerase Chain Reaction; Zika Virus Infection

We tested a sample of 234 wild long-tailed macaques (Macaca fascicularis) trapped in Peninsular Malaysia in 2009, 2010, and 2016 for Zika virus RNA and antibodies. None were positive for RNA, and only 1.3% were seropositive for neutralizing antibodies. Long-tailed macaques are unlikely to be reservoirs for Zika virus in Malaysia.

Topics: Animals; Animals, Wild; Macaca fascicularis; Malaysia; Monkey Diseases; RNA, Viral; Serogroup; Zika Virus; Zika Virus Infection

A major outbreak of the Zika virus (ZIKV) has been reported in Brazil in 2015. Since then, it spread further to other countries in the Americas and resulted in declaration of the Public Health Emergency of International Concern (PHEIC) by World Health Organization. In 2016, Singapore reported its first minor ZIKV epidemic. Malaysia shares similar ecological environment as Brazil and Singapore which may also favor ZIKV transmission. However, no ZIKV outbreak has been reported in Malaysia to date. This study aimed to discuss all confirmed ZIKV cases captured under Malaysia ZIKV surveillance system after declaration of the PHEIC; and explore why Malaysia did not suffer a similar ZIKV outbreak as the other two countries.. This was an observational study reviewing all confirmed ZIKV cases detected in Malaysia through the ZIKV clinical surveillance and Flavivirus laboratory surveillance between June 2015 and December 2017. All basic demographic characteristics, co-morbidities, clinical, laboratory and outcome data of the confirmed ZIKV cases were collected from the source documents.. Only eight out of 4043 cases tested positive for ZIKV infection during that period. The median age of infected patients was 48.6 years and majority was Chinese. Two of the subjects were pregnant. The median interval between the onset of disease and the first detection of ZIKV Ribonucleic Acid (RNA) in body fluid was 3 days. Six cases had ZIKV RNA detected in both serum and urine samples. Phylogenetic analysis suggests that isolates from the 7 cases of ZIKV infection came from two clusters, both of which were local circulating strains.. Despite similar ecological background characteristics, Malaysia was not as affected by the recent ZIKV outbreak compared to Brazil and Singapore. This could be related to pre-existing immunity against ZIKV in this population, which developed after the first introduction of the ZIKV in Malaysia decades ago. A serosurvey to determine the seroprevalence of ZIKV in Malaysia was carried out in 2017. The differences in circulating ZIKV strains could be another reason as to why Malaysia seemed to be protected from an outbreak.

Topics: Adult; Disease Outbreaks; Female; Humans; Malaysia; Male; Middle Aged; Phylogeny; Pregnancy; Seroepidemiologic Studies; Zika Virus; Zika Virus Infection

The aim of this study was to examine the willingness of pregnant women to have prenatal screening for the Zika virus (ZIKV). Secondly, the study also assessed the acceptability of a hypothetical Zika vaccination and its association with the health belief model (HBM) constructs. A cross-sectional study was conducted from 4th October to 11th November 2016, among pregnant women who attended antenatal care at the University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia. The majority (81.8%) was willing to be tested for ZIKV and 78% felt that their spouse would be willing to be tested for ZIKV. A total of 94% expressed a willingness to receive a Zika vaccination if available. The participants expressed high perceived benefits of a ZIKV vaccination. Although many have a high perception of the severity of ZIKV, the proportion with a strong perception of their susceptibility to ZIKV was low. In the multivariate analysis of all the HBM constructs, cue-to-action, namely physician recommendation (odds ratio [OR]=2.288; 95% confidence interval [CI] 1.093-4.793) and recommendation from friends or relatives (OR=4.030; 95% CI 1.694-9.587), were significantly associated with a willingness to be vaccinated against ZIKV. The favourable response to a Zika vaccination implies that more research attention has to be given to develop a vaccine against ZIKV. Should the vaccine be available in the future, publicity and healthcare providers would play a vital role in ensuring vaccine uptake among pregnant women.

Topics: Adult; Cross-Sectional Studies; Female; Health Knowledge, Attitudes, Practice; Humans; Malaysia; Patient Acceptance of Health Care; Pregnancy; Pregnancy Complications, Infectious; Pregnant Women; Vaccination; Zika Virus; Zika Virus Infection

The aims of this study were to explore the differences in (1) the perception of severity towards ZIKV infection and dengue fever, and (2) mosquito control practices before and after the ZIKV outbreak were declared a Public Health Emergency of International Concern (PHEIC). Data were collected between Feb to May 2016 using a computer-assisted telephone interviewing system. The median scale score for perceived severity of ZIKV was 3 (interquartile range [IQR] 1-5) versus 4 (IQR 3-5) for dengue (P < 0.001). The scores for mosquito control practices before and after ZIKV was declared a PHEIC were similar, at 4 (IQR 3-5). Multivariate analysis revealed that participants with a higher score for perception of severity of ZIKV were more likely to report greater mosquito control practices after the declaration of the PHEIC (OR 1.822 [95% CI 1.107-2.998]). The emerging ZIKV pandemic requires concerted efforts to enhance mosquito control practices among the Malaysian public. Efforts to improve public mosquito control practices should focus on enhancing the perception of the severity of ZIKV.

Topics: Adolescent; Adult; Cross-Sectional Studies; Dengue; Female; Health Knowledge, Attitudes, Practice; Humans; Malaysia; Male; Middle Aged; Mosquito Control; Young Adult; Zika Virus Infection

Zika virus (ZIKV) has re-emerged to cause explosive epidemics in the Pacific and Latin America, and appears to be associated with severe neurological complications including microcephaly in babies. ZIKV is transmitted to humans by Aedes mosquitoes, principally Ae. aegypti, and there is historical evidence of ZIKV circulation in Southeast Asia. It is therefore clear that Malaysia is at risk of similar outbreaks. Local and international guidelines are available for surveillance, diagnostics, and management of exposed and infected individuals. ZIKV is the latest arbovirus to have spread globally beyond its initial restricted niche, and is unlikely to be the last. Innovative new methods for surveillance and control of vectors are needed to target mosquito-borne diseases as a whole.

Topics: Aedes; Animals; Humans; Malaysia; Mosquito Vectors; Zika Virus; Zika Virus Infection

Perceptions about illnesses may influence self-care and preventive health behaviours. Illness perceptions of the Zika virus (ZIKV) infection were investigated under the framework of the Self-Regulation Model of Illness. Illness perception differences between ZIKV and dengue fever were also examined. Lastly, associations between illness perceptions of ZIKV with mosquito prevention practices were studied. Samples were drawn from landline telephone numbers using computer-assisted telephone interviewing in Malaysia. A total of 567 respondents completed the survey between February 2015 and May 2016. The median and interquartile range (IQR) for the total six dimensions of illness perceptions score was higher for dengue (23.0 (IQR 17.0-28.0)) than ZIKV (20.0 (IRQ 11.0-28.0)),

Topics: Adolescent; Adult; Animals; Dengue; Female; Health Knowledge, Attitudes, Practice; Humans; Malaysia; Male; Middle Aged; Mosquito Control; Young Adult; Zika Virus Infection

Topics: Aedes; Animals; Haplorhini; Hemagglutination Inhibition Tests; Malaysia; Neutralization Tests; Serotyping; Zika Virus; Zika Virus Infection