Original Contribution


, Volume 7, Issue 2, pp 213-225

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

Persistence of Highly Pathogenic Avian Influenza H5N1 Virus Defined by Agro-Ecological Niche

  • Lenny HogerwerfAffiliated withBiological Control and Spatial Ecology, Université Libre de Bruxelles CP160/12Division of Epidemiology, Department of Farm Animal Health, Utrecht University
  • , Rob G. WallaceAffiliated withInstitute for Global Studies, University of Minnesota
  • , Daniela OttavianiAffiliated withFood and Agriculture Organization of the United Nations (FAO)
  • , Jan SlingenberghAffiliated withFood and Agriculture Organization of the United Nations (FAO)
  • , Diann ProsserAffiliated withUSGS Patuxent Wildlife Research Center
  • , Luc BergmannAffiliated withDepartment of Geography, University of Minnesota
  • , Marius GilbertAffiliated withBiological Control and Spatial Ecology, Université Libre de Bruxelles CP160/12Fonds National de la Recherche Scientifique Email author 


The highly pathogenic avian influenza (HPAI) H5N1 virus has spread across Eurasia and into Africa. Its persistence in a number of countries continues to disrupt poultry production, impairs smallholder livelihoods, and raises the risk a genotype adapted to human-to-human transmission may emerge. While previous studies identified domestic duck reservoirs as a primary risk factor associated with HPAI H5N1 persistence in poultry in Southeast Asia, little is known of such factors in countries with different agro-ecological conditions, and no study has investigated the impact of such conditions on HPAI H5N1 epidemiology at the global scale. This study explores the patterns of HPAI H5N1 persistence worldwide, and for China, Indonesia, and India includes individual provinces that have reported HPAI H5N1 presence during the 2004–2008 period. Multivariate analysis of a set of 14 agricultural, environmental, climatic, and socio-economic factors demonstrates in quantitative terms that a combination of six variables discriminates the areas with human cases and persistence: agricultural population density, duck density, duck by chicken density, chicken density, the product of agricultural population density and chicken output/input ratio, and purchasing power per capita. The analysis identifies five agro-ecological clusters, or niches, representing varying degrees of disease persistence. The agro-ecological distances of all study areas to the medoid of the niche with the greatest number of human cases are used to map HPAI H5N1 risk globally. The results indicate that few countries remain where HPAI H5N1 would likely persist should it be introduced.


global ecology highly pathogenic avian influenza agro-ecology epidemiology