, Volume 9, Issue 1, pp 60–69 | Cite as

Highly Pathogenic H5N1 Avian Influenza Viruses Exhibit Few Barriers to Gene Flow in Vietnam

  • Margaret Carrel
  • Xiu-Feng Wan
  • Tung Nguyen
  • Michael Emch
Original Contribution


Locating areas where genetic change is inhibited can illuminate underlying processes that drive evolution of pathogens. The persistence of highly pathogenic H5N1 avian influenza in Vietnam since 2003, and the continuous molecular evolution of Vietnamese avian influenza viruses, indicates that local environmental factors are supportive not only of incidence but also of viral adaptation. This article explores whether gene flow is constant across Vietnam, or whether there exist boundary areas where gene flow exhibits discontinuity. Using a dataset of 125 highly pathogenic H5N1 avian influenza viruses, principal components analysis and wombling analysis are used to indicate the location, magnitude, and statistical significance of genetic boundaries. Results show that a small number of geographically minor boundaries to gene flow in highly pathogenic H5N1 avian influenza viruses exist in Vietnam, but that overall there is little division in genetic exchange. This suggests that differences in genetic characteristics of viruses from one region to another are not the result of barriers to H5N1 viral exchange in Vietnam, and that H5N1 avian influenza is able to spread relatively unimpeded across the country.


H5N1 avian influenza gene flow wombling Vietnam 


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Copyright information

© International Association for Ecology and Health 2012

Authors and Affiliations

  • Margaret Carrel
    • 1
  • Xiu-Feng Wan
    • 2
  • Tung Nguyen
    • 3
  • Michael Emch
    • 4
  1. 1.Department of GeographyUniversity of IowaIowa CityUSA
  2. 2.Department of Basic Sciences, College of Veterinary MedicineMississippi State UniversityMississippi StateUSA
  3. 3.Department of Animal HealthNational Center for Veterinary DiagnosticsHanoiVietnam
  4. 4.Department of GeographyUniversity of North Carolina-Chapel HillChapel HillUSA

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