Risk Mapping of African Swine Fever in Domestic Pigs and Wild Boars to Enhance Management and Surveillance in Asia

Abstract

African swine fever (ASF) is a highly lethal disease affecting domestic pigs and wild boars, caused by the ASF virus (ASFV), which has rapidly spread across Asia in recent years. In this region, most reported ASF cases involve domestic pigs, while cases in wild boars remain notably lower except in a few countries. However, factors such as the high population of wild boars, limited wildlife surveillance, and inadequate farm biosecurity suggest that the prevalence and transmission of ASFV between these hosts may be underestimated. Therefore, we used a simplified multicriteria approach (SMCA) to identify vulnerable areas (VAs) for ASFV infection and validated the resulting VA maps with chi-square tests using reported ASF cases. The spatial SMCA revealed that VAs for ASFV infection in domestic pigs are concentrated in eastern China, while high-risk zones for ASFV infection in wild boars span Russia, eastern China, and Southeast Asia. Sensitity analysis showed that the variables that most influenced the risk of ASFV infection in domestic pigs and wild boars were anthropogenic factors and distribution of wild boars, respectively. Additionally, we predicted areas with significant transmission potential between domestic pigs and wild boars. High-risk regions for interspecies transmission include eastern China, southwestern Korea, and southern Japan. This study offers a standardized method to assess ASFV infection risk across Asia by integrating environmental and anthropogenic factors rather than relying solely on reported outbreaks. The findings highlight potential high-risk regions, including those without detected outbreaks, to improve surveillance and early detection strategies