Anthropogenic factors and the risk of highly pathogenic avian influenza H5N1: prospects from a spatial-based model

Paul, Mathilde; Tavornpanich, Saraya; Abrial, David; Gasqui, Patrick; Charras-Garrido, Myriam; Thanapongtharm, Weerapong; Xiao, Xiangming; Gilbert, Marius; Roger, Francois; Ducrot, Christian

The fact that surveillance was strengthened in response to the large HPAI epidemic makes Thailand a prime place to analyse which factors play an important role in the spread of the disease. A set of environmental risk factors was identified in Thailand [8] , but aside from the findings of Tiensin et al. [24] , little has been learned about anthropogenic risk factors in the country. Some aspects of the role of human activities in HPAI risk were recently reported from Vietnam [19] . The discovery of HPAI H5N1 in Thai poultry markets in 2006 and 2007 [2] suggests that the HPAI virus has continued to spread among poultry through trade activities despite the presence of control measures. Apart from the duck-rice agro-ecosystem which has been shown to be a source of infection, the role of humans in the spread of HPAI H5N1 has not yet been fully investigated. The risk of HPAI varies spatially according to the anthropogenic characteristics of the different geographical areas of interest, each characterized by a variety of human activities such as poultry farming practices, trade activities and market rules, land use and agro-ecosystems, and veterinary services structure and control. The objective of the present work was to study, through a spatial approach, the risk factors of HPAI H5N1 linked to human activities. It complements previous work by identifying the high-risk areas of HPAI H5N1 in Thailand and by determining which anthropogenic factors are associated with an increased risk.