Japanese encephalitis virus outbreak in Australian pigs

Abstract

An incursion of Japanese encephalitis virus disease has been identified as commencing in north-eastern Australia in April 2021, resulting in prolonged gestation length, mummified and stillborn piglets, often with severe fetal abnormalities and congenital tremors. The disease has been recognised to have occurred on nearly 80 farms over an 18-month period with some seasonal impacts and large mosquito numbers afflicting farms. There have been no obvious clinical problems in piglets, weaners, grow/finishing or adult pigs. The organism is zoonotic and caused clinical infection in nearly 40 people and sadly resulted in the death of five people. None of the people showing clinical signs had contact with the pig industry. No one involved in the pig industry or students handling potentially infected tissues showed any clinical signs of disease.