19 results on '"Peiris, J. S. Malik"'
Search Results
2. Comparison of the NucliSens easyMAG and Qiagen BioRobot 9604 nucleic acid extraction systems for detection of RNA and DNA respiratory viruses in nasopharyngeal aspirate samples.
- Author
-
Chan KH, Yam WC, Pang CM, Chan KM, Lam SY, Lo KF, Poon LL, and Peiris JS
- Subjects
- Automation, Hong Kong, Hospitals, Humans, Polymerase Chain Reaction methods, Sensitivity and Specificity, DNA Viruses isolation & purification, DNA, Viral isolation & purification, Nasopharynx virology, RNA Viruses isolation & purification, RNA, Viral isolation & purification, Virology methods, Virus Diseases diagnosis
- Abstract
The NucliSens easyMAG and BioRot 9604 automated nucleic acid extraction systems were evaluated and compared with the manual QIAamp (Qiagen) extraction method for their abilities to extract nucleic acid from nasopharyngeal aspirate samples for the detection of RNA and DNA respiratory viruses. The nucleic acids recovered by all three methods gave comparable sensitivities in PCR tests, and the three methods gave comparable viral loads. There was no evidence of residual PCR inhibitors and no evidence of PCR cross-contamination.
- Published
- 2008
- Full Text
- View/download PDF
3. Reconstructing household transmission dynamics to estimate the infectiousness of asymptomatic influenza virus infections.
- Author
-
Tim K. Tsang, Can Wang, Fang, Vicky J., Perera, Ranawaka A. P. M., Hau Chi So, Ip, Dennis K. M., Leung, Gabriel M., Peiris, J. S. Malik, Cauchemez, Simon, and Cowling, Benjamin J.
- Subjects
VIRUS diseases ,INFECTIOUS disease transmission ,INFLUENZA viruses ,HOUSEHOLDS ,INFLUENZA - Abstract
There has long been controversy over the potential for asymptomatic cases of the influenza virus to have the capacity for onward transmission, but recognition of asymptomatic transmission of COVID-19 stimulates further research into this topic. Here, we develop a Bayesian methodology to analyze detailed data from a large cohort of 727 households and 2515 individuals in the 2009 pandemic influenza A(H1N1) outbreak in Hong Kong to characterize household transmission dynamics and to estimate the relative infectiousness of asymptomatic versus symptomatic influenza cases. The posterior probability that asymptomatic cases [36% of cases; 95% credible interval (CrI): 32%, 40%] are less infectious than symptomatic cases is 0.82, with estimated relative infectiousness 0.57 (95% CrI: 0.11, 1.54). More data are required to strengthen our understanding of the contribution of asymptomatic cases to the spread of influenza. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
4. Indirect Protection from Vaccinating Children against Influenza A Virus Infection in Households.
- Author
-
Tsang, Tim K., Wang, Can, Fang, Vicky J., Perera, Ranawaka A. P. M., So, Hau Chi, Ip, Dennis K. M., Peiris, J. S. Malik, Leung, Gabriel M., Cauchemez, Simon, and Cowling, Benjamin J.
- Subjects
VACCINATION of children ,VIRUS diseases ,INFLUENZA ,INFLUENZA A virus ,FLU vaccine efficacy ,INFLUENZA viruses ,VACCINE effectiveness - Abstract
Influenza vaccination is an important intervention to prevent influenza virus infection. Our previous analysis suggested that indirect protection is limited in an influenza B epidemic in Hong Kong. We further analyzed six influenza A epidemics to determine such potential. We applied a statistical model to estimate household transmission dynamics in the 3 influenza A(H3N2) and 3 pandemic influenza A(H1N1) epidemics. Then, we estimated the reduction in infection risk among unvaccinated household members when all children in households are vaccinated, with different assumptions on vaccine efficacy (VE). In the optimal scenario that VE was 70%, the reduction to the total probability of infection was only marginal, with relative probabilities ranged from 0.91–0.94 when all children in households were vaccinated because community was by far the main source of infection during the six epidemics in our study. The proportion of cases attributed to household transmission was 10% (95% CrI: 7%, 13%). Individual influenza vaccination is important even when other household members are vaccinated, given the degree of indirect protection is small. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
5. Cellular tropism of SARS-CoV-2 in the respiratory tract of Syrian hamsters and B6.Cg-Tg(K18-ACE2)2Prlmn/J transgenic mice.
- Author
-
Yen, Hui-Ling, Valkenburg, Sophie, Sia, Sin Fun, Choy, Ka Tim, Peiris, J. S. Malik, Wong, Karen H. M., Crossland, Nicholas, Douam, Florian, and Nicholls, John M.
- Subjects
HAMSTERS ,TRANSGENIC mice ,GOLDEN hamster ,SARS-CoV-2 ,RESPIRATORY organs ,VIRUS diseases ,SARS disease ,PATHOLOGICAL physiology - Abstract
Several animal models have been developed to study the pathophysiology of SARS-CoV-2 infection and to evaluate vaccines and therapeutic agents for this emerging disease. Similar to infection with SARS-CoV-1, infection of Syrian hamsters with SARS-CoV-2 results in moderate respiratory disease involving the airways and lung parenchyma but does not lead to increased mortality. Using a combination of immunohistochemistry and transmission electron microscopy, we showed that the epithelium of the conducting airways of hamsters was the primary target for viral infection within the first 5 days of infection, with little evidence of productive infection of pneumocytes. At 6 days postinfection, antigen was cleared but parenchymal damage persisted, and the major pathological changes resolved by day 14. These findings are similar to those previously reported for hamsters with SARS-CoV-1 infection. In contrast, infection of K18-hACE2 transgenic mice resulted in pneumocyte damage, with viral particles and replication complexes in both type I and type II pneumocytes together with the presence of convoluted or cubic membranes; however, there was no evidence of virus replication in the conducting airways. The Syrian hamster is a useful model for the study of SARS-CoV-2 transmission and vaccination strategies, whereas infection of the K18-hCE2 transgenic mouse results in lethal disease with fatal neuroinvasion but with sparing of conducting airways. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
6. Effects of Nonpharmaceutical COVID-19 Interventions on Pediatric Hospitalizations for Other Respiratory Virus Infections, Hong Kong.
- Author
-
Chiu, Susan S., Cowling, Benjamin J., Peiris, J. S. Malik, Chan, Eunice L. Y., Wong, Wilfred H. S., Kwok Piu Lee, and Lee, Kwok Piu
- Subjects
VIRUS diseases ,ACUTE diseases ,RESPIRATORY infections ,RESPIRATORY syncytial virus ,ENTEROVIRUS diseases ,COVID-19 - Abstract
To determine the effects of nonpharmaceutical interventions (NPIs) for coronavirus disease on pediatric hospitalizations for infection with respiratory viruses other than severe acute respiratory syndrome coronavirus 2, we analyzed hospital data for 2017-2021. Compared with 2017-2019, age-specific hospitalization rates associated with respiratory viruses greatly decreased in 2020, when NPIs were in place. Also when NPIs were in place, rates of hospitalization decreased among children of all ages for infection with influenza A and B viruses, respiratory syncytial virus, adenovirus, parainfluenza viruses, human metapneumovirus, and rhinovirus/enterovirus. Regression models adjusted for age and seasonality indicated that hospitalization rates for acute febrile illness/respiratory symptoms of any cause were reduced by 76% and by 85%-99% for hospitalization for infection with these viruses. NPIs in Hong Kong were clearly associated with reduced pediatric hospitalizations for respiratory viruses; implementing NPIs and reopening schools were associated with only a small increase in hospitalizations for rhinovirus/enterovirus infections. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
7. Variation by lineage in serum antibody responses to influenza B virus infections.
- Author
-
Lau, Yiu Chung, Perera, Ranawaka A. P. M., Fang, Vicky J., Luk, Long Hei, Chu, Daniel K. W., Wu, Peng, Barr, Ian G., Peiris, J. S. Malik, and Cowling, Benjamin J.
- Subjects
INFLUENZA B virus ,VIRUS diseases ,ANTIBODY formation ,ANTIBODY titer - Abstract
Two lineages of influenza B virus currently co-circulate and have distinct antigenicity, termed Victoria and Yamagata after the B/Victoria/2/87 and B/Yamagata/16/88 strains, respectively. We analyzed antibody titer dynamics following PCR-confirmed influenza B virus infection in a longitudinal community-based cohort study conducted in Hong Kong from 2009–2014 to assess patterns in changes in antibody titers to B/Victoria and B/Yamagata viruses following infections with each lineage. Among 62 PCR-confirmed cases, almost half had undetectable hemagglutination inhibition (HAI) antibody titers to the lineage of infection both pre-infection and post-infection. Among those infected with influenza B/Victoria who showed an HAI titer response after infection, we found strong rises to the lineage of infection, positive but smaller cross-lineage HAI titer boosts, a small dependence of HAI titer boosts on pre-infection titers, and a shorter half-life of HAI titers in adults. Our study is limited by the low HAI sensitivity for non-ether-treated IBV antigen and the incapacity of performing other assays with higher sensitivity, as well as the mismatch between the B/Yamagata lineage circulating strain and the assay strain in one of the study seasons. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
8. Host DNA released by NETosis in neutrophils exposed to seasonal H1N1 and highly pathogenic H5N1 influenza viruses.
- Author
-
Chan, Louisa L. Y., Nicholls, John M., Peiris, J. S. Malik, Lau, Yu Lung, Chan, Michael C. W., and Chan, Renee W. Y.
- Subjects
INFLUENZA A virus, H5N1 subtype ,INFLUENZA viruses ,H5N1 Influenza ,VIRUS diseases ,INFLUENZA A virus, H1N1 subtype ,NEUTROPHILS - Abstract
Background: Neutrophil is of the most abundant number in human immune system. During acute influenza virus infection, neutrophils are already active in the early phase of inflammation - a time in which clinical biopsy or autopsy material is not readily available. However, the role of neutrophil in virus infection is not well understood. Here, we studied the role of neutrophil in host defense during influenza A virus infection, specifically assessing if it contributes to the differential pathogenesis in H5N1 disease.Methods: Neutrophils were freshly isolated from healthy volunteers and subjected to direct influenza H1N1 and H5N1 virus infection in vitro. The ability of the naïve neutrophils to infiltrate from the basolateral to the apical phase of the influenza virus infected alveolar epithelium was assessed. The viral replication, innate immune responses and Neutrophil extracellular trap (NET) formation of neutrophils upon influenza virus infection were evaluated.Results: Our results demonstrated that influenza virus infected alveolar epithelium allowed neutrophil transmigration. Significantly more neutrophils migrated across the H5N1 influenza virus infected the epithelium than the counterpart infected by the seasonal influenza H1N1 virus infected. Neutrophils were equally susceptible to H5N1 and H1N1 virus infection with similar viral gene transcription. Productive replication was observed in H5N1 infected neutrophils. H5N1 induced higher cytokine and chemokine gene transcription than H1N1 infected neutrophils, including TNF-α, IFN-β, CXCL10, MIP-1α and IL-8. This inferred a more intense inflammatory response posed by H5N1 than H1N1 virus. Strikingly, NADPH oxidase-independent NET formation was only observed in H1N1 infected neutrophils at 6 hpi while no NET formation was observed upon H5N1 infection.Conclusion: Our data is the first to demonstrate that NET formation is abrogated in H5N1 influenza virus infection and might contribute to the severity of H5N1 disease. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
9. Assessing the fitness of distinct clades of influenza A (H9N2) viruses
- Author
-
Sonnberg, Stephanie, Van de Velde, Lee Ann, Baranovich, Tatiana, Bridges, Olga, Burnham, Andrew, Carey, David, Cline, Troy D., Crumpton, Jeri C., DeBeauchamp, Jennifer, Duan, Susu, Ducatez, Mariette F., Elbahesh, Husni, KOÇER, ZEYNEP AHSEN, Fabrizio, Thomas P., Forrest, Heather L., Franks, John, Freiden, Pamela, Govorkova, Elena A., Guan, Yi, Jeevan, Trushar, Jones, Jeremy C., Kaplan, Bryan S., Karlsson, Erik A., Kercher, Lisa A., Krauss, Scott, Little, Beth, Marathe, Bindumadhav M., McClaren, Jennifer L., Meliopoulos, Victoria A., O'Brien, Kevin B., Oguin, Thomas H., Oshansky, Christine M., Peiris, J. S. Malik, Prevost, Kristi, Rubrum, Adam, Russell, Charles J., Sanders, Catherine J., Seiler, Patrick, Seufzer, Bradley J., Shanmuganatham, Karthik K., Stoner, Terri D., Turner, Jasmine, Thomas, Paul G., Schultz-Cherry, Stacey, Zaraket, Hassan, Zanin, Mark, Yoon, Sun-Woo, Wong, Sook-San, Webster, Robert G., Webby, Richard J., Van de Velde, Nicholas C., Interactions hôtes-agents pathogènes [Toulouse] (IHAP), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Vétérinaire de Toulouse (ENVT), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, NIH/NIAID [HHSN266200700005C], and American Lebanese Syrian Associated Charities at St Jude
- Subjects
zoonose ,grippe ,040301 veterinary sciences ,Epidemiology ,[SDV]Life Sciences [q-bio] ,viruses ,animal diseases ,Immunology ,Biology ,medicine.disease_cause ,Microbiology ,Zoonotic disease ,zoonotic disease ,0403 veterinary science ,03 medical and health sciences ,antivirals ,Virology ,Drug Discovery ,medicine ,Clade ,Gene ,030304 developmental biology ,Genetics ,Domestic avian species ,0303 health sciences ,risk assessment ,virus diseases ,Influenza a ,04 agricultural and veterinary sciences ,General Medicine ,virus pathogène ,antiviral ,Influenza A virus subtype H5N1 ,3. Good health ,Infectious Diseases ,Diverse population ,Original Article ,Parasitology ,influenza ,évaluation des risques ,human activities ,viral pathogenicity - Abstract
International audience; Influenza A (H9N2) viruses are a genetically diverse population that infects wild and domestic avian species and mammals and contributed the internal gene segments to the A/H5N1 and A/H7N9 viruses associated with lethal human infections. Here we comprehensively assess the potential risk to mammals of a diverse panel of A/H9N2 viruses, representing the major H9N2 clades, using a combination of in vitro assays (e.g., antiviral susceptibility and virus growth in primary differentiated human airway cells) and in vivo assays (e. g., replication, transmission and/or pathogenicity of viruses in ducks, pigs, mice and ferrets). We observed that viruses isolated from humans, A/Hong Kong/1073/1999 and A/Hong Kong/33982/2009, had the highest risk potential. However, the A/swine/Hong Kong/9A-1/1998 and A/chicken/Hong Kong/G9/1997 viruses also displayed several features suggesting a fitness profile adapted to human infection and transmission. The North American avian H9N2 clade virus had the lowest risk profile, and the other viruses tested displayed various levels of fitness across individual assays. In many cases, the known genotypic polymorphisms alone were not sufficient to accurately predict the virus' phenotype. Therefore, we conclude that comprehensive risk analyses based on surveillance of circulating influenza virus strains are necessary to assess the potential for human infection by emerging influenza A viruses.
- Published
- 2013
10. Molecular Epidemiology of Clade 1 Influenza A Viruses (H5N1), Southern Indochina Peninsula, 2004–2007
- Author
-
Peiris, J S Malik, Buchy, Philippe, Fourment, Mathieu, Mardy, Sek, Sorn, San, Holl, Davun, Ly, Sowath, Vong, Sirenda, Enouf, Vincent, Peiris, J.S. Malik, Van Der Werf, Silvie, Centre de recherche Université de Hong-Kong-Pasteur, Réseau International des Instituts Pasteur (RIIP), Institut Pasteur du Cambodge, Ministry of Agriculture, Forestry and Fisheries [Cambodia], Génétique moléculaire des virus à ARN, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), This study was supported by the French Ministry of Health, the French Agency for Development and the US Department of Human Health Services., Buchy P, Fourment M, Mardy S, Sorn S, Holl D, Ly S, Vong S, Enouf V, Peiris JS, van der Werf S., and Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Time Factors ,Epidemiology ,viruses ,animal diseases ,lcsh:Medicine ,medicine.disease_cause ,Disease Outbreaks ,Influenza A Virus ,Influenza A virus ,MESH: Animals ,MESH: Disease Outbreaks ,Clade ,Molecular Epidemiology ,0303 health sciences ,MESH: Influenza, Human ,poultry ,Dispatch ,transmission ,virus diseases ,H5N1 ,Thailand ,Infectious Diseases ,Vietnam ,MESH: Birds ,[SDV.MP.VIR]Life Sciences [q-bio]/Microbiology and Parasitology/Virology ,H5N1 Subtype ,influenza ,Cambodia ,Human ,Microbiology (medical) ,medicine.medical_specialty ,MESH: Influenza A Virus, H5N1 Subtype ,Wild ,Animals, Wild ,Biology ,Microbiology ,Virus ,lcsh:Infectious and parasitic diseases ,Birds ,03 medical and health sciences ,MESH: Influenza in Birds ,Molecular genetics ,Influenza, Human ,parasitic diseases ,medicine ,MESH: Molecular Epidemiology ,Animals ,Humans ,MESH: Animals, Wild ,lcsh:RC109-216 ,wild birds ,030304 developmental biology ,MESH: Humans ,Influenza A Virus, H5N1 Subtype ,Molecular epidemiology ,030306 microbiology ,MESH: Cambodia ,MESH: Time Factors ,lcsh:R ,Influenza a ,Virology ,Influenza A virus subtype H5N1 ,Influenza in Birds ,Indochina peninsula - Abstract
International audience; To determine the origin of influenza A virus (H5N1) epizootics in Cambodia, we used maximum-likelihood and Bayesian methods to analyze the genetic sequences of subtype H5N1 strains from Cambodia and neighboring areas. Poultry movements, rather than repeated reintroduction of subtype H5N1 viruses by wild birds, appear to explain virus circulation and perpetuation.
- Published
- 2009
11. A Robust Parameter Estimation Method for Estimating Disease Burden of Respiratory Viruses.
- Author
-
Chan, King Pan, Wong, Chit Ming, Chiu, Susan S. S., Chan, Kwok Hung, Wang, Xi Ling, Chan, Eunice L. Y., Peiris, J. S. Malik, and Yang, Lin
- Subjects
RESPIRATORY diseases ,VIRUS diseases ,POISSON'S ratio ,HOSPITAL care ,LABORATORIES ,SCIENTIFIC observation - Abstract
Background: Poisson model has been widely applied to estimate the disease burden of influenza, but there has been little success in providing reliable estimates for other respiratory viruses. Methods: We compared the estimates of excess hospitalization rates derived from the Poisson models with different combinations of inference methods and virus proxies respectively, with the aim to determine the optimal modeling approach. These models were validated by comparing the estimates of excess hospitalization attributable to respiratory viruses with the observed rates of laboratory confirmed paediatric hospitalization for acute respiratory infections obtained from a population based study. Results: The Bayesian inference method generally outperformed the classical likelihood estimation, particularly for RSV and parainfluenza, in terms of providing estimates closer to the observed hospitalization rates. Compared to the other proxy variables, age-specific positive counts provided better estimates for influenza, RSV and parainfluenza, regardless of inference methods. The Bayesian inference combined with age-specific positive counts also provided valid and reliable estimates for excess hospitalization associated with multiple respiratory viruses in both the 2009 H1N1 pandemic and interpandemic period. Conclusions: Poisson models using the Bayesian inference method and virus proxies of age-specific positive counts should be considered in disease burden studies on multiple respiratory viruses. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
12. Heterogeneity in Viral Shedding Among Individuals With Medically Attended Influenza A Virus Infection.
- Author
-
Lau, Lincoln L. H., Ip, Dennis K. M., Nishiura, Hiroshi, Fang, Vicky J., Chan, Kwok-Hung, Peiris, J. S. Malik, Leung, Gabriel M., and Cowling, Benjamin J.
- Subjects
VIRAL shedding ,INFLUENZA transmission ,VIRUS diseases ,AGE groups ,COMMUNICABLE diseases ,SEASONAL influenza - Abstract
Compared with the average transmissibility of human influenza A virus, much less attention has been paid to the potential variability in its transmissibility. We considered viral shedding as a proxy for infectiousness and explored the heterogeneity of infectiousness among patients with medically attended seasonal influenza A virus infection. The analysis revealed that viral shedding is more heterogeneous in children than in adults. The top 20% most infectious children and adults were estimated to be responsible for 89%–96% and 78%–82%, respectively, of the total infectiousness in each age group. Further investigation is required to correlate the substantial variations in viral shedding with heterogeneity in actual transmissibility. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
13. Viral Shedding and Clinical Illness in Naturally Acquired Influenza Virus Infections.
- Author
-
Lau, Lincoln L. H., Cowling, Benjamin J., Fang, Vicky J., Kwok-Hung Chan, Lau, Eric H. Y., Lipsitch, Marc, Cheng, Calvin K. Y., Houck, Peter M., Uyeki, Timothy M., Peiris, J. S. Malik, and Leung, Gabriel M.
- Subjects
INFLUENZA viruses ,VIRUS diseases ,QUANTITATIVE research ,POLYMERASE chain reaction ,SEASONAL influenza ,VIRAL load ,INFECTIOUS disease transmission - Abstract
Background. Volunteer challenge studies have provided detailed data on viral shedding from the respiratory tract before and through the course of experimental influenza virus infection. There are no comparable quantitative data to our knowledge on naturally acquired infections. Methods. In a community-based study in Hong Kong in 2008, we followed up initially healthy individuals to quantify trends in viral shedding on the basis of cultures and reverse-transcription polymerase chain reaction (RT-PCR) through the course of illness associated with seasonal influenza A and B virus infection. Results. Trends in symptom scores more closely matched changes in molecular viral loads measured with RT-PCR for influenza A than for influenza B. For influenza A virus infections, the replicating viral loads determined with cultures decreased to undetectable levels earlier after illness onset than did molecular viral loads. Most viral shedding occurred during the first 2-3 days after illness onset, and we estimated that 1%-8% of infectiousness occurs prior to illness onset. Only 14% of infections with detectable shedding at RT-PCR were asymptomatic, and viral shedding was low in these cases. Conclusions. Our results suggest that "silent spreaders" (ie, individuals who are infectious while asymptomatic or presymptomatic) may be less important in the spread of influenza epidemics than previously thought. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
14. DAS181, a sialidase fusion protein, protects human airway epithelium against influenza virus infection: an in vitro pharmacodynamic analysis.
- Author
-
Triana-Baltzer, Gallen B., Babizki, Maria, Chan, Michael C. W., Wong, Adam C. N., Aschenbrenner, Laura M., Campbell, Erin R., Qi-Xiang Li, Chan, Renee W. Y., Peiris, J. S. Malik, Nicholls, John M., and Fang Fang
- Subjects
NEURAMINIDASE ,VIRUS diseases ,INFLUENZA ,ANTI-infective agents ,INFLUENZA viruses ,RESPIRATORY infections - Abstract
Objectives: The influenza virus (IFV) infection models commonly used to evaluate antiviral agents (e.g. MDCK cell line and mice) are limited by physiological differences from the human respiratory tract in vivo. Here we report the pharmacodynamics of DAS181, a sialidase fusion protein that inhibits influenza infection, in the model systems of well-defined human airway epithelium (HAE) culture and ex vivo culture of fresh human bronchial tissue, both of which are close mimics of the human respiratory tract in vivo. [ABSTRACT FROM PUBLISHER]
- Published
- 2010
- Full Text
- View/download PDF
15. Characterization of Avian Influenza Viruses A (H5N1) from Wild Birds, Hong Kong, 2004-2008.
- Author
-
Smith, Gavin J. D., Vijaykrishna, Dhanasekaran, Ellis, Trevor M., Dyrting, Kitman C., Leung, Y. H. Connie, Bahl, Justin, Wong, Chun W., Kai, Huang, Chow, Mary K. W., Duan, Lian, Chan, Allen S. L., Zhang, Li Juan, Chen, Honglin, Luk, Geraldine S. M., Peiris, J. S. Malik, and Guan, Yi
- Subjects
AVIAN influenza ,BIRD diseases ,ANIMAL species ,POULTRY ,VIRUS diseases - Abstract
From January 2004 through June 2008, surveillance of dead wild birds in Hong Kong, People's Republic of China, periodically detected highly pathogenic avian influenza (HPAI) viruses (H5N1) in individual birds from different species. During this period, no viruses of subtype H5N1 were detected in poultry on farms and in markets in Hong Kong despite intensive surveillance. Thus, these findings in wild birds demonstrate the potential for wild birds to disseminate HPAI viruses (H5N1) to areas otherwise free from the viruses. Genetic and antigenic characterization of 47 HPAI (H5N1) viruses isolated from dead wild birds in Hong Kong showed that these isolates belonged to 2 antigenically distinct virus groups: clades 2.3.4 and 2.3.2. Although research has shown that clade 2.3.4 viruses are established in poultry in Asia, the emergence of clade 2.3.2 viruses in nonpasserine birds from Hong Kong, Japan, and Russia raises the possibility that this virus lineage may have become established in wild birds. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
16. Broad Cross-Protection against H5N1 Avian Influenza Virus Infection by Means of Monoclonal Antibodies that Map to Conserved Viral Epitopes.
- Author
-
Yixin Chen, Kun Qin, Wai Lan Wu, Guoqiang Li, Jun Zhang, Hailian Du, Mun Hon Ng, Shih, J. Wai-Kuo, Peiris, J. S. Malik, Yi Guan, Honglin Chen, and Ningshao Xia
- Subjects
AVIAN influenza ,VIRUS diseases ,IMMUNOGLOBULINS ,MONOCLONAL antibodies ,IMMUNIZATION ,RESPIRATORY infections ,ANIMAL vaccination ,MICE ,IMMUNE serums - Abstract
Background. Passive immunization with human H5 antisera or H5-specific monoclonal antibodies (MAbs) has potential as an effective treatment for acute H5N1 influenza virus infection, but its efficacy against antigenically diverse H5N1 viruses is unconfirmed. Methods. Cross-protection against antigenically diverse H5N1 strains with H5-specific MAbs, generated by successive immunization of antigenically distinct strains, was evaluated in mice. Results. A panel of 52 broadly cross-reactive H5 specific MAbs were generated and characterized. One of these MAbs, 13D4, has been demonstrated to protect mice against lethal challenge by 4 H5N1 strains representing the current major genetic populations, clades 1, 2.1, 2.2, and 2.3, even at a stage of infection when H5N1 virus has disseminated beyond the pulmonary system. Complete neutralization of virus in lung tissue of infected animals was observed 24 h after treatment with 13D4. Mapping of this MAb with escape mutants showed it to bind to 2 conserved, possibly critical, sites of H5N1 hemagglutinin, 152 and 182. Conclusion. Generation of broadly cross-protective MAbs against H5N1 influenza virus may be optimized by selecting MAbs that target conserved sites in hemagglutinin. H5 MAbs such as 13D4 may prove to have therapeutic value in controlling infection due to current and future H5N1 variants. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
17. Poultry drinking water used for avian influenza surveillance.
- Author
-
Leung, Y. H. Connie, Li-Juan Zhang, Chun-Kin Chow, Chun-Lok Tsang, Chi-Fung Ng, Chun-Kuen Wong, Yi Guan, Peiris, J. S. Malik, Zhang, Li-Juan, Chow, Chun-Kin, Tsang, Chun-Lok, Ng, Chi-Fung, Wong, Chun-Kuen, and Guan, Yi
- Subjects
DRINKING water ,ANIMAL cages ,POULTRY diseases ,INFLUENZA ,VIRUS diseases ,RESPIRATORY infections ,AVIAN influenza epidemiology ,ANIMAL experimentation ,AVIAN influenza ,BIRDS ,COMPARATIVE studies ,DIGESTION ,FECES ,RESEARCH methodology ,MEDICAL cooperation ,POULTRY ,PUBLIC health surveillance ,RESEARCH ,AQUATIC microbiology ,EVALUATION research ,INFLUENZA A virus - Abstract
Samples of drinking water from poultry cages, which can be collected conveniently and noninvasively, provide higher rates of influenza (H9N2) virus isolation than do samples of fecal droppings. Studies to confirm the usefulness of poultry drinking water for detecting influenza (H5N1) should be conducted in disease-endemic areas. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
18. Social contacts and the locations in which they occur as risk factors for influenza infection.
- Author
-
Kwok, Kin O., Cowling, Benjamin J., Wei, Vivian W. I., Wu, Kendra M., Read, Jonathan M., Lessler, Justin, Cummings, Derek A., Peiris, J. S. Malik, and Riley, Steven
- Subjects
INFLUENZA ,SOCIAL contact ,VIRUS diseases ,ECOLOGICAL heterogeneity ,REGRESSION analysis ,SEROLOGY ,DISEASE risk factors - Abstract
The interaction of human social behaviour and transmission is an intriguing aspect of the life cycle of respiratory viral infections. Although age-specific mixing patterns are often assumed to be the key drivers of the age-specific heterogeneity in transmission, the association between social contacts and biologically confirmed infection has not previously been tested at the individual level. We administered a questionnaire to participants in a longitudinal cohort survey of influenza in which infection was defined by longitudinal paired serology. Using a variety of statistical approaches, we found overwhelming support for the inclusion of individual age in addition to contact variables when explaining odds of infection: the best model not including age explained only 15.7% of the deviance, whereas the best model with age explained 23.6%. However, within age groups, we did observe an association between contacts, locations and infection: median numbers of contacts (or locations) reported by those infected were higher than those from the uninfected group in every age group other than the youngest. Further, we found some support for the retention of location and contact variables in addition to age in our regression models, with excess odds of infection of approximately 10% per additional 10 contacts or one location. These results suggest that, although the relationship between age and incidence of respiratory infection at the level of the individual is not driven by self-reported social contacts, risk within an age group may be. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
19. Tissue Tropism of Swine Influenza Viruses and Reassortants in Ex Vivo Cultures of the Human Respiratory Tract and Conjunctiva.
- Author
-
Chan, Renee W. Y., Kang, Sara S. R., Hui-Ling Yen, Li, Alan C. L., Tang, Lynsia L. S., Yu, Wendy C. L., Yuen, Kit M., Chan, Icarus W. W., Wong, Diana D. Y., Lai, Wico W., Kwong, Dora L. W., Sihoe, Alan D. L., Poon, Leo L. M., Yi Guan, Nicholls, John M., Peiris, J. S. Malik, and Chan, Michael C. W.
- Subjects
- *
RESPIRATORY infections , *SWINE influenza , *INFLUENZA viruses , *VIRUS diseases , *MICROORGANISMS - Abstract
The 2009 pandemic influenza H1N1 (H1N1pdm) virus was generated by reassortment of swine influenza viruses of different lineages. This was the first influenza pandemic to emerge in over 4 decades and the first to occur after the realization that influenza pandemics arise from influenza viruses of animals. In order to understand the biological determinants of pandemic emergence, it is relevant to compare the tropism of different lineages of swine influenza viruses and reassortants derived from them with that of 2009 pandemic H1N1 (H1N1pdm) and seasonal influenza H1N1 viruses in ex vivo cultures of the human nasopharynx, bronchus, alveoli, and conjunctiva. We hypothesized that virus which can transmit efficiently between humans replicated well in the human upper airways. As previously reported, H1N1pdm and seasonal H1N1 viruses replicated efficiently in the nasopharyngeal, bronchial, and alveolar epithelium. In contrast, representative viruses from the classical swine (CS) (H1N1) lineage could not infect human respiratory epithelium; Eurasian avian-like swine (EA) (H1N1) viruses only infected alveolar epithelium and North American triple-reassortant (TRIG) viruses only infected the bronchial epithelium albeit inefficiently. Interestingly, a naturally occurring triple-reassortant swine virus, A/SW/HK/915/04 (H1N2), with a matrix gene segment of EA swine derivation (i.e., differing from H1N1pdm only in lacking a neuraminidase [NA] gene of EA derivation) readily infected and replicated in human nasopharyngeal and bronchial epithelia but not in the lung. A recombinant sw915 with the NA from H1N1pdm retained its tropism for the bronchus and acquired additional replication competence for alveolar epithelium. In contrast to H1N1pdm, none of the swine viruses tested nor seasonal H1N1 had tropism in human conjunctiva. Recombinant viruses generated by swapping the surface proteins (hemagglutinin and NA) of H1N1pdm and seasonal H1N1 virus demonstrated that these two gene segments together are key determinants of conjunctival tropism. Overall, these findings suggest that ex vivo cultures of the human respiratory tract provide a useful biological model for assessing the human health risk of swine influenza viruses. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.