The spread of the H5N1 bird flu epidemic in Asia in 2004

  • R. G. Webster
  • Y. Guan
  • L. Poon
  • S. Krauss
  • R. Webby
  • E. Govorkova
  • M. Peiris


H5N1 avian influenza has spread to eight countries in eastern Asia including China, Japan, South Korea, Vietnam, Laos, Cambodia, Thailand, and Indonesia in early 2004. This H5N1 influenza A virus is extremely virulent in poultry including chickens and ducks, killing millions of birds throughout the region. Additionally this virus has transmitted to humans (mainly children) in Vietnam, Cambodia, and Thailand, killing 54 of 100 diagnosed persons. To control this epidemic hundreds of millions of chickens and ducks have been culled. One genotype of H5N1 designated “Z” has become dominant in Asia. This viruswas first detected in wild birds in Hong Kong in November 2002 and was antigenically distinct from H5N1 viruses isolated from 1997 to early 2002 and lethal for aquatic birds.

The H5N1 virus infecting humans and poultry in Asia in 2004 is an antigenic variant of the Z genotype. Here we consider the possible role of migrating birds in the evolution and spread of the H5N1 influenza A virus throughout Asia. We conclude that the available information is consistent with a role for migrating birds but limited information is available and that serological studies are urgently needed on migrating birds worldwide. The prospect is that this H5N1/04 influenza A virus will become endemic in poultry in eastern Asia and will be a continuing threat to animal and human health. It is also projected that a human H5N1 vaccine will eventually be needed.


H5N1 Virus Wild Bird Migrate Bird Aquatic Bird Grey Heron 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag/Wien 2005

Authors and Affiliations

  • R. G. Webster
    • 1
    • 2
    • 3
  • Y. Guan
    • 2
  • L. Poon
    • 2
  • S. Krauss
    • 1
  • R. Webby
    • 1
  • E. Govorkova
    • 1
  • M. Peiris
    • 2
  1. 1.Division of Virology, Department of Infectious DiseasesSt. Jude Children’s Research HospitalMemphisUSA
  2. 2.Department of MicrobiologyThe University of Hong KongPokfulam, Hong Kong, SARChina
  3. 3.World Health Organization Collaborating Center for Studies on the Ecology of Influenza in Animals and BirdsMemphisUSA

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