PLoS ONE (Jan 2011)

Wild bird migration across the Qinghai-Tibetan plateau: a transmission route for highly pathogenic H5N1.

  • Diann J Prosser,
  • Peng Cui,
  • John Y Takekawa,
  • Mingjie Tang,
  • Yuansheng Hou,
  • Bridget M Collins,
  • Baoping Yan,
  • Nichola J Hill,
  • Tianxian Li,
  • Yongdong Li,
  • Fumin Lei,
  • Shan Guo,
  • Zhi Xing,
  • Yubang He,
  • Yuanchun Zhou,
  • David C Douglas,
  • William M Perry,
  • Scott H Newman

DOI
https://doi.org/10.1371/journal.pone.0017622
Journal volume & issue
Vol. 6, no. 3
p. e17622

Abstract

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BACKGROUND: Qinghai Lake in central China has been at the center of debate on whether wild birds play a role in circulation of highly pathogenic avian influenza virus H5N1. In 2005, an unprecedented epizootic at Qinghai Lake killed more than 6000 migratory birds including over 3000 bar-headed geese (Anser indicus). H5N1 subsequently spread to Europe and Africa, and in following years has re-emerged in wild birds along the Central Asia flyway several times. METHODOLOGY/PRINCIPAL FINDINGS: To better understand the potential involvement of wild birds in the spread of H5N1, we studied the movements of bar-headed geese marked with GPS satellite transmitters at Qinghai Lake in relation to virus outbreaks and disease risk factors. We discovered a previously undocumented migratory pathway between Qinghai Lake and the Lhasa Valley of Tibet where 93% of the 29 marked geese overwintered. From 2003-2009, sixteen outbreaks in poultry or wild birds were confirmed on the Qinghai-Tibet Plateau, and the majority were located within the migratory pathway of the geese. Spatial and temporal concordance between goose movements and three potential H5N1 virus sources (poultry farms, a captive bar-headed goose facility, and H5N1 outbreak locations) indicated ample opportunities existed for virus spillover and infection of migratory geese on the wintering grounds. Their potential as a vector of H5N1 was supported by rapid migration movements of some geese and genetic relatedness of H5N1 virus isolated from geese in Tibet and Qinghai Lake. CONCLUSIONS/SIGNIFICANCE: This is the first study to compare phylogenetics of the virus with spatial ecology of its host, and the combined results suggest that wild birds play a role in the spread of H5N1 in this region. However, the strength of the evidence would be improved with additional sequences from both poultry and wild birds on the Qinghai-Tibet Plateau where H5N1 has a clear stronghold.