DIVERSITY AND DISTRIBUTION OF INFLUENZA A VIRUSES AMONG WILD BIRDS IN EASTERN SIBERIA

Abstract

Influenza A virus (IAV) is a worldwide pathogen of humans and animals. In nature IAV is associated with aquatic birds. The regular survey of natural populations of aquatic birds is important to describe the diversity of IAV, evaluate pathogenic potential of circulating strains for human and domestic animals and reveal possible routes of virus spread during seasonal migrations of wild birds. In this paper the results of annual ecological and viroiogicai survey among wild birds of Eastern Siberia performed between 2005 and 2012 are presented. The cloacal swabs and tissue samples from 901 wild birds were analyzed for presence of IAV using virus isolation in chicken embryos and/or PCR assay. The subtype of IAV was established using haemaggiutintion inhibition assay and genome sequencing. Seventeen subtypes of IAV were discovered including H1N1, H5N1, HswNl, H0N1, H1N4, HlNlsw, H2N2, H3N2, H3N5, H3N6, H3N8, H4N6, H7N1, H7N8, H10N7, H13N6, H13N8. Highest prevalence of infection was detected among wild ducks Anas crecca (18.3 %), A. platyrhynchos (13.8 %) and herring gull Larus argentatus (6.5 %). The most diverse virus population was revealed in Irkutsk Region among L. argentatus that hosted subtypes H3, H6N1 and H9. In the Republic of Tuva and Krasnoyarsk territory H3N8, H5N1 and H7 subtypes were detected. The wild birds from Republic of Khakassia were shown to hostH4 subtype, whereas in Republic of Buryatia subtypes H3 and H4 were detected in wild ducks and herring gulls. Possible routes of IAV spread and epidemiological implications are discussed.

Keywords

• influenza a virus
• bird species
• diagnostics of influenza virus
• distribution
• bird migrations
• eastern siberia
• central siberia