Prevalence and Distribution of Avian Influenza A(H5N1) Virus Clade Variants in Live Bird Markets of Vietnam, 2011-2013
Active surveillance for avian influenza (AI) viruses in poultry sold at live bird markets (LBMs) was conducted in 44 of 63 provinces throughout Vietnam over two periods from September 2011 to February 2012 and October 2012 to June 2013. The study objectives were to assess the prevalence of avian inf...
| Main Authors: | , , , , , , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
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American Association of Avian Pathologists
2014
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| _version_ | 1797099440220143616 |
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| author | Nguyen, D Bryant, J Davis, C Nguyen, L Pham, LT Loth, L Inui, K Nguyen, T Jang, Y To, T Nguyen, T Hoang, D Do, H Nguyen, T Newman, S Siembieda, J Pham, D |
| author_facet | Nguyen, D Bryant, J Davis, C Nguyen, L Pham, LT Loth, L Inui, K Nguyen, T Jang, Y To, T Nguyen, T Hoang, D Do, H Nguyen, T Newman, S Siembieda, J Pham, D |
| author_sort | Nguyen, D |
| collection | OXFORD |
| description | Active surveillance for avian influenza (AI) viruses in poultry sold at live bird markets (LBMs) was conducted in 44 of 63 provinces throughout Vietnam over two periods from September 2011 to February 2012 and October 2012 to June 2013. The study objectives were to assess the prevalence of avian influenza type A, H5, and H5N1 subtype viruses and characterize the geographical and temporal distribution of H5N1 virus genetic variants across the country. Monthly sampling was conducted in 394 LBMs located in 372 communes. A total of 9790 oropharyngeal swabs from poultry were screened for influenza A virus by real-time reverse-transcriptase PCR. Virus isolation was attempted on all positive samples in embryonated chicken eggs, and the HA1 region of each H5 virus isolate was sequenced. Market prevalence of H5 subtype virus was 32.2% (127/394) over the cumulative 15 mo of surveillance. Phylogenetic analyses indicated that clade 1.1 viruses persisted in the south, whereas three genetically distinct subgroups of clade 2.3.2.1 were found simultaneously in northern, central, and southern Vietnam. Clade 2.3.2.1c viruses first appeared in July 2012 and spread rapidly to the center and south of Vietnam in late 2012, where they were predominant among clade 2.3.2.1 viruses and were detected in both active LBM surveillance and poultry outbreaks. Given the overlapping geographic distribution of clade variants and the antigenic divergence previously described for these clades, current AI poultry vaccines used in Vietnam may require bivalent formulations containing representatives of both clade 1.1 and clade 2.3.2.1 viruses. |
| first_indexed | 2024-03-07T05:23:44Z |
| format | Journal article |
| id | oxford-uuid:dfd4c334-0fc1-46e7-b72e-bfd7a4ffd06e |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T05:23:44Z |
| publishDate | 2014 |
| publisher | American Association of Avian Pathologists |
| record_format | dspace |
| spelling | oxford-uuid:dfd4c334-0fc1-46e7-b72e-bfd7a4ffd06e2022-03-27T09:42:16ZPrevalence and Distribution of Avian Influenza A(H5N1) Virus Clade Variants in Live Bird Markets of Vietnam, 2011-2013Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:dfd4c334-0fc1-46e7-b72e-bfd7a4ffd06eEnglishSymplectic Elements at OxfordAmerican Association of Avian Pathologists2014Nguyen, DBryant, JDavis, CNguyen, LPham, LTLoth, LInui, KNguyen, TJang, YTo, TNguyen, THoang, DDo, HNguyen, TNewman, SSiembieda, JPham, DActive surveillance for avian influenza (AI) viruses in poultry sold at live bird markets (LBMs) was conducted in 44 of 63 provinces throughout Vietnam over two periods from September 2011 to February 2012 and October 2012 to June 2013. The study objectives were to assess the prevalence of avian influenza type A, H5, and H5N1 subtype viruses and characterize the geographical and temporal distribution of H5N1 virus genetic variants across the country. Monthly sampling was conducted in 394 LBMs located in 372 communes. A total of 9790 oropharyngeal swabs from poultry were screened for influenza A virus by real-time reverse-transcriptase PCR. Virus isolation was attempted on all positive samples in embryonated chicken eggs, and the HA1 region of each H5 virus isolate was sequenced. Market prevalence of H5 subtype virus was 32.2% (127/394) over the cumulative 15 mo of surveillance. Phylogenetic analyses indicated that clade 1.1 viruses persisted in the south, whereas three genetically distinct subgroups of clade 2.3.2.1 were found simultaneously in northern, central, and southern Vietnam. Clade 2.3.2.1c viruses first appeared in July 2012 and spread rapidly to the center and south of Vietnam in late 2012, where they were predominant among clade 2.3.2.1 viruses and were detected in both active LBM surveillance and poultry outbreaks. Given the overlapping geographic distribution of clade variants and the antigenic divergence previously described for these clades, current AI poultry vaccines used in Vietnam may require bivalent formulations containing representatives of both clade 1.1 and clade 2.3.2.1 viruses. |
| spellingShingle | Nguyen, D Bryant, J Davis, C Nguyen, L Pham, LT Loth, L Inui, K Nguyen, T Jang, Y To, T Nguyen, T Hoang, D Do, H Nguyen, T Newman, S Siembieda, J Pham, D Prevalence and Distribution of Avian Influenza A(H5N1) Virus Clade Variants in Live Bird Markets of Vietnam, 2011-2013 |
| title | Prevalence and Distribution of Avian Influenza A(H5N1) Virus Clade Variants in Live Bird Markets of Vietnam, 2011-2013 |
| title_full | Prevalence and Distribution of Avian Influenza A(H5N1) Virus Clade Variants in Live Bird Markets of Vietnam, 2011-2013 |
| title_fullStr | Prevalence and Distribution of Avian Influenza A(H5N1) Virus Clade Variants in Live Bird Markets of Vietnam, 2011-2013 |
| title_full_unstemmed | Prevalence and Distribution of Avian Influenza A(H5N1) Virus Clade Variants in Live Bird Markets of Vietnam, 2011-2013 |
| title_short | Prevalence and Distribution of Avian Influenza A(H5N1) Virus Clade Variants in Live Bird Markets of Vietnam, 2011-2013 |
| title_sort | prevalence and distribution of avian influenza a h5n1 virus clade variants in live bird markets of vietnam 2011 2013 |
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