Evidence of Japanese Encephalitis Virus Exposure in Feral Pig Populations in North Queensland, Australia

Several animal species, including horses and pigs, can be infected with Japanese encephalitis virus (JEV). Feral pigs (Sus scrofa) are considered an effective amplifying host for JEV in natural habitats. In this study, 265 dried blood spots were collected from feral pigs in four selected North Queensland local government areas, and antibodies against JEV were detected using a competitive enzyme-linked immunosorbent assay (cELISA). The results showed that 26.4% (70/265) of the feral pigs had antibodies specific to JEV. We found a significant difference in the seroprevalence of JEV in the Wet Tropics (p < 0.05), compared to the Dry Tropics region of North Queensland. The results indicate that feral pigs in North Queensland have been exposed to JEV, suggesting that they may play an important role as an amplifying host. These findings may inform the planning of mitigation measures through a multisectoral One Health approach.