JEV SYMPOSIUM: POTENTIAL ANIMAL HOSTS OF JEV IN NORTH AMERICA

A recent symposium held at the Center for the Ecology of Infectious Disease at the University of Georgia, sponsored in part by the Swine Health Information Center, addressed issues surrounding a 2022 outbreak of Japanese encephalitis in Australia affecting humans and animals. Reacting to the JE occurrence, SHIC along with the US pork industry began monitoring Australia’s situation and response to the outbreak. SHIC immediately began encouraging prevention and preparedness activities as pigs are JEV amplifying hosts. One major objective of the symposium was to further JEV prevention, preparation and control for the US. As such, identifying animals other than domestic pigs that can serve as JEV hosts in North America was a major topic of discussion.

Feral Pigs in the US

Charles Taylor with the UGA Savannah River Ecology Lab and Warnell School of Forestry and Natural Resources presented information on history, management, and current research on feral pigs in the US. As vectors, feral swine are competent for over 45 diseases and parasites, a significant concern for any foreign animal disease including JEV, as demonstrated in Australia. 

Feral swine are one of most destructive invasive vertebrates in North America, per Taylor, costing $1.5 billion in damage in the US annually affecting agriculture, forestry, and property. Regional management efforts began in the 1990s with a shift in perception and management of feral pigs, Taylor remarked, but  did not become aggressively managed on a national scale until the mid 2010s. The National Feral Swine Damage Management Program, launched in 2014, includes research, disease monitoring, tool development, communication/outreach, and control measures. Both lethal and non-lethal management strategies are employed for control.

Today, pockets of feral swine in the US have developed over centuries from genetics mixed with Eurasian boars. A rapid shift in population size and distribution of feral swine ramped up in the 1980s and 1990s. Canada is not immune to the spread of feral pigs with a spike there beginning in the 2000s. Taylor described this recent expansion in the US and Canada as a “pig bomb.”