Japanese Encephalitis Virus Research Program

About the Japanese Encephalitis Virus Research Program

Japanese encephalitis virus (JEV) is an emerging disease identified through global disease monitoring as a priority for North American prevention and preparedness activities. JEV is a zoonotic disease transmitted by Culex mosquitoes infected with the virus, and it relies on waterbirds as a natural reservoir host. The virus, capable of infecting pigs, horses and humans, is currently not present in the U.S., but the U.S. represents a geographic region susceptible to its introduction.

Historically, JEV has been primarily maintained in endemic Southeast Asia and Pacific Island nations. In 2022, an outbreak of JEV genotype IV spread rapidly across new geographic regions of Australia affecting breeding swine herds and causing reproductive failure, delayed farrowing, stillbirths, mummified fetuses, abortions and weak piglets. This recent incursion of a new JEV genotype into areas previously free from the disease, like Australia with an invasion and expansion of JEV genotype IV in its eastern and southeastern states, warrants the need for a close investigation of this disease and its potential for incursion and establishment in the U.S.

The Swine Health Information Center and the Foundation for Food & Agriculture Research have partnered to fund a $1 million research program to enhance U.S. prevention, preparedness and response capabilities for JEV. Understanding the potential impacts of JEV on U.S. pork production is critical to protecting the health of the U.S. swine herd as well as mitigating the risk of this emerging disease. Critical research investments are necessary to prevent JEV incursion, ensure rapid detection of JEV if introduced, inform stakeholder response, mitigate production losses on the sow farm, identify effective control measures. and develop clear messaging to consumers on the safety of pork.