Skip to main content
ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Exotic & Emerging Avian Viral Diseases Research » Research » Publications at this Location » Publication #372074
Research Project: Intervention Strategies to Prevent and Control Disease Outbreaks Caused by Emerging Strains of Avian Influenza Viruses

Location: Exotic & Emerging Avian Viral Diseases Research

Title: Genetic evolution and transmission dynamics of clade 2.3.2.1a highly pathogenic avian influenza A/H5N1 viruses in Bangladesh

Author
item KWON, JUNGHOON - Consultant
item LEE, DONG-HUN - University Of Connecticut
item CRIADO, MIRIA FERREIRA - Consultant
item Killmaster, Lindsay
item ALI, MD ZULFEKAR - Bangladesh Agricultural Research Institute
item GIASUDDIN, MOHAMMAD - Bangladesh Agricultural Research Institute
item Swayne, David

Submitted to: Virus Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/3/2020
Publication Date: 6/13/2020
Citation: Kwon, J., Lee, D., Criado, M., Killmaster, L.F., Ali, M., Giasuddin, M., Swayne, D.E. 2020. Genetic evolution and transmission dynamics of clade 2.3.2.1a highly pathogenic avian influenza A/H5N1 viruses in Bangladesh. Virus Evolution. 6(2):veaa046. https://doi.org/10.1093/ve/veaa046.
DOI: https://doi.org/10.1093/ve/veaa046

Interpretive Summary: The deadly H5N1 form, high pathogenicity, of avian influenza viruses (HPAIVs) have been caused continuous poultry outbreak in Bangladesh since 2007, despite the use of vaccine. In this study, we analyzed gene information and mutations of the HPAIVs, to better understand how the viruses changed. Our analysis suggests that the major genotype has been replaced and domestic ducks in Bangladesh played a major role in persistence, spread, evolution and genotype replacement of HPAIVs in Bangladesh.

Technical Abstract: Asian lineage A/H5N1 highly pathogenic avian influenza viruses (HPAIVs) have been responsible for continuous outbreaks in Bangladesh since 2007. Although clades 2.2.2 and 2.3.4.2 HPAIVs have disappeared since poultry vaccination was introduced in 2012, clade 2.3.2.1a viruses have continued to be detected in Bangladesh. In this study, we identified A/H9N2 (n¼15), A/H5N1 (n¼19), and A/H5N1-A/H9N2 (n¼18) mixed viruses from live bird markets, chicken farms, and wild house crows (Corvus splendens) in Bangladesh from 2016 to 2018. We analyzed the genetic sequences of the H5 HPAIVs, to better understand the evolutionary history of clade 2.3.2.1a viruses in Bangladesh. Although seven HA genetic subgroups (B1–B7) and six genotypes (G1, G1.1, G1.2, G2, G2.1, and G2.2) have been identified in Bangladesh, only subgroup B7 and genotypes G2, G2.1, and G2.2 were detected after 2016. The replacement of G1 genotype by G2 in Bangladesh was possibly due to vaccination and viral competition in duck populations. Initially, genetic diversity decreased after introduction of vaccination in 2012, but in 2015, genetic diversity increased and was associated with the emergence of genotype G2. Our phylodynamic analysis suggests that domestic Anseriformes, including ducks and geese, may have played a major role in persistence, spread, evolution, and genotype replacement of clade 2.3.2.1a HPAIVs in Bangladesh. Thus, improvements in biosecurity and monitoring of domestic Anseriformes are needed for more effective control of HPAI in Bangladesh.