The Evidence of Clade 7.1 Avian Influenza Virus (H5N1) in Qinghai Lake

Wen Wang,Xuelian Wang,Laixing Li,Fang Yang,Sisi Zheng,Zhuo Li,Hao Sun,Kirill Sharshov

doi:10.4236/aim.2016.614098

Abstract

The highly pathogenic influenza A virus subtype H5N1 spread throughout Asia since 2003, reached to Europe in 2005, and the Middle East, as well as Africa and caused a global concern for a potential pandemic threat last decade. A Clade 2.3.2 H5N1 virus became dominate in the Qinghai Lake region in 2009 with sporadic mammal cases of infection and transferred to Russia and Europe through wild migratory birds. Currently, HPAI H5N1 of clades 2.3.4, 2.3.2, and 7 are the dominant co-circulating H5N1 viruses in poultry in Asia. 2.3.2 Clade is dominant in wild birds through the world whereas there is no evident data about Clade 7 circulation in wild birds. We detected HPAI H5N1 virus of Clade 7.1 in Qinghai Lake, that closely related to Shanxi-like and Vietnam viruses co-circulating in poultry. This is the first report of Clade 7.1 H5N1 in wild birds. Based on phylogenetic analyses, the virus can be originated from Clade 7.1 virus gene pool that spread in Vietnam and Chinese poultry and could spread with migratory birds to Qinghai Lake. The Qinghai Lake continues to be significant hotspot for H5N1 surveillance since the regular outbreaks occurred there in wild birds and mammals. Based on these facts and findings, the related researchers should pay more attention to the Qinghai Lake basin as significant hotspot for H5N1 avian influenza surveillance since the regular H5N1 outbreaks occurred there in wild birds with sporadic mammal cases of infection.

Highlights

Avian influenza is a viral disease adapted to birds, drawing more attention all over the world [1]
We detected HPAI H5N1 virus of Clade 7.1 in Qinghai Lake, that closely related to Shanxi-like and Vietnam viruses co-circulating in poultry
The virus can be originated from Clade 7.1 virus gene pool that spread in Vietnam and Chinese poultry and could spread with migratory birds to Qinghai Lake

Summary

Introduction

Avian influenza is a viral disease adapted to birds, drawing more attention all over the world [1]. In 2005, a great amount of migratory birds were infected by HPAI H5N1 in Qinghai Lake region (northwest of China) which resulted the death of over 6000 birds [4] [6] [8]. Based on their phylogenetic analysis, these viruses were classified as Clade 2.2 [9]. In 2009, a novel H5N1 virus lineage Clade 2.3.2 became dominate in the Qinghai Lake region with sporadic mammal cases of infection [11] [12], and transferred to Russia and Europe through wild migratory birds [13]. 2.3.2 clade is dominant in wild birds through the world but there is no evident data about clade 7 isolation from wild birds reported

Methods

Results

Discussion

Conclusion