Wild and Domestic Pig Interactions at the Wildlife–Livestock Interface of Murchison Falls National Park, Uganda, and the Potential Association with African Swine Fever Outbreaks

Bushpigs (Potamochoerus larvatus) and warthogs (Phacochoerus africanus), which are widely distributed in Eastern Africa, are likely to cohabitate in the same environment with domestic pigs, facilitating the transmission of shared pathogens. However, potential interactions between bushpig, warthog and domestic pig and the resulting potential circulation of infectious diseases have rarely been investigated in Africa to date. In order to understand the dynamics of such interactions and the potential influence of human behavior and husbandry practices on them, individual interviews (n=233) and participatory rural appraisals (n=11) were carried out among Ugandan pig farmers at the edge of Murchison Falls National Park, northern Uganda. In addition, as an example of possible implications of wild and domestic pig interactions, nonlinear multivariate analysis (multiple correspondence analyses) was used to investigate the potential association between the aforementioned factors (interactions and human behavior and practices) and farmer reported ASF outbreaks. No direct interactions between wild pigs and domestic pig were reported in our study area. However, indirect interactions were described by 83 (35.6 %) of the participants and were identified to be more common at water sources during the dry season. Equally, eight (3.4%) farmers declared exposing their domestic pig to raw hunting leftovers of wild pigs. The exploratory analysis performed suggested possible associations between the farmer reported ASF outbreaks and indirect interactions, free-range housing systems, dry season, and having a warthog burrow less than 3km from the household. Our study was useful to gather local knowledge and to identify knowledge gaps about potential interactions between wild and domestic pig in this area. This information could be useful to facilitate the design of future observational studies to better understand the potential transmission of pathogens between wild and domestic pigs.