New evidence for the east–west spread of the highly pathogenic avian influenza H5N1 virus between Central Asian and east Asian-Australasian flyways in China

Bram Vrancken,Jun Lu,Tian Ma,Dongping Liu,Xiang Zhao,Yunfeng Li,Wendong Ru,Hongxuan He,Sarah François,Qiqi Yang,Lixia Chen,Weiyue Meng,Guogang Zhang,Ruyi Gao,Zhuo Chen,Huaiyu Tian

doi:10.1080/22221751.2019.1623719

Abstract

ABSTRACT The spread of highly pathogenic avian influenza (HPAI) H5N1 virus is associated with wild fowl migration in East Asian-Australasian (EA) and Central Asian (CA) flyways. However, the spread of H5N1 virus between the two flyways is still unclear. Here, the movements of wild waterfowl were obtained from satellite tracking data covering seven bar-headed geese and three great black-headed gulls breeding in the Qinghai Lake area (along the EA flyway), and 20 whooper swans wintering in the Sanmenxia Reservoir area (at the CA flyway). From the 2688 samples that were screened from wild birds at Qinghai Lake after an outbreak of H5N1 in July 2015, four genomes of H5N1 virus were obtained from bar-headed geese. The results of phylogenetic analysis indicated that these H5N1 viruses belonged to clade 2.3.2.1c and their gene fragments were highly homologous with A/whooper swan/Henan/SMX1/2015 (H5N1) virus (ranging from 99.76% to 100.00%) isolated from a dead whooper swan from the Sanmenxia Reservoir area along the EA flyway in January 2015. Furthermore, the coincidental timing of the H5N1 outbreak with spring migration, together with phylogenetic evidence, provided new evidence of the east-to-west spread of HPAI H5N1 between the EA and CA migratory flyways of China.

Highlights

In 2005, there was an outbreak of highly pathogenic avian influenza (HPAI) H5N1 in wild bird populations at Qinghai Lake in west China along the Central Asian (CA) flyway
In January 2015, 96 waterfowl, including whooper swans (Cygnus cygnus) and common pochard (Aythya ferina) wintering in Sanmenxia in mid-China along the East Asian-Australasian (EA) flyway died from H5N1 [3]
The migration routes of seven bar-headed geese (Anser indicus) and three great black-headed gulls (Larus ichthyaetus) breeding in the Qinghai Lake area and 20 whooper swans wintering in Sanmenxia were tracked by satellite from 2006 to 2015 [6–8] (Table S1)

Summary

Introduction

In 2005, there was an outbreak of highly pathogenic avian influenza (HPAI) H5N1 in wild bird populations at Qinghai Lake in west China along the Central Asian (CA) flyway. The migration routes of seven bar-headed geese (Anser indicus) and three great black-headed gulls (Larus ichthyaetus) breeding in the Qinghai Lake area and 20 whooper swans wintering in Sanmenxia were tracked by satellite from 2006 to 2015 [6–8] (Table S1).

Results

Conclusion