title: Genetically Diverse Low Pathogenicity Avian Influenza A Virus Subtypes Co-Circulate among Poultry in Bangladesh.
abstract: Influenza virus surveillance, poultry outbreak investigations and genomic sequencing were assessed to understand the ecology and evolution of low pathogenicity avian influenza (LPAI) A viruses in Bangladesh from 2007 to 2013. We analyzed 506 avian specimens collected from poultry in live bird markets and backyard flocks to identify influenza A viruses. Virus isolation-positive specimens (n = 50) were subtyped and their coding-complete genomes were sequenced. The most frequently identified subtypes among LPAI isolates were H9N2, H11N3, H4N6, and H1N1. Less frequently detected subtypes included H1N3, H2N4, H3N2, H3N6, H3N8, H4N2, H5N2, H6N1, H6N7, and H7N9. Gene sequences were compared to publicly available sequences using phylogenetic inference approaches. Among the 14 subtypes identified, the majority of viral gene segments were most closely related to poultry or wild bird viruses commonly found in Southeast Asia, Europe, and/or northern Africa. LPAI subtypes were distributed over several geographic locations in Bangladesh, and surface and internal protein gene segments clustered phylogenetically with a diverse number of viral subtypes suggesting extensive reassortment among these LPAI viruses. H9N2 subtype viruses differed from other LPAI subtypes because genes from these viruses consistently clustered together, indicating this subtype is enzootic in Bangladesh. The H9N2 strains identified in Bangladesh were phylogenetically and antigenically related to previous human-derived H9N2 viruses detected in Bangladesh representing a potential source for human infection. In contrast, the circulating LPAI H5N2 and H7N9 viruses were both phylogenetically and antigenically unrelated to H5 viruses identified previously in humans in Bangladesh and H7N9 strains isolated from humans in China. In Bangladesh, domestic poultry sold in live bird markets carried a wide range of LPAI virus subtypes and a high diversity of genotypes. These findings, combined with the seven year timeframe of sampling, indicate a continuous circulation of these viruses in the country.
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States of America.
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Gerloff
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
authors.forename: Salah Uddin
authors.initials: SU
authors.lastname: Khan
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States of America.
authors.forename: Natosha
authors.initials: N
authors.lastname: Zanders
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States of America.
authors.forename: Amanda
authors.initials: A
authors.lastname: Balish
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
authors.forename: Najmul
authors.initials: N
authors.lastname: Haider
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
authors.forename: Ausraful
authors.initials: A
authors.lastname: Islam
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
authors.forename: Sukanta
authors.initials: S
authors.lastname: Chowdhury
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
authors.forename: Mahmudur Ziaur
authors.initials: MZ
authors.lastname: Rahman
authors.affiliation: Department of Livestock Services, Ministry of Fisheries and Livestock, Dhaka, Bangladesh.
authors.forename: Ainul
authors.initials: A
authors.lastname: Haque
authors.affiliation: EcoHealth Alliance, New York, United States of America.
authors.forename: Parviez
authors.initials: P
authors.lastname: Hosseini
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
authors.forename: Emily S
authors.initials: ES
authors.lastname: Gurley
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Luby
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States of America.
authors.forename: David E
authors.initials: DE
authors.lastname: Wentworth
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States of America.
authors.forename: Ruben O
authors.initials: RO
authors.lastname: Donis
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States of America.|International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
authors.forename: Katharine
authors.initials: K
authors.lastname: Sturm-Ramirez
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States of America.
authors.forename: C Todd
authors.initials: CT
authors.lastname: Davis
mesh_terms: D000818:Animals; D001459:Bangladesh; D002645:Chickens / Q000821:virology; D004372:Ducks / Q000821:virology; D014644:Genetic Variation; D016679:Genome, Viral; D005838:Genotype; D005843:Geography; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics; D006801:Humans; D009980:Influenza A virus / Q000235:genetics*; D005585:Influenza in Birds / Q000821:virology; D007251:Influenza, Human / Q000821:virology; D010802:Phylogeny; D011200:Poultry / Q000821:virology*; D011201:Poultry Diseases; D011634:Public Health
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus