Japanese encephalitis virus is a vector-borne viral disease occurring in Asia Pacific region and is the leading cause of encephalitis across Asia. Nearly half the world’s population live in areas where JEV occurs. The annual incidence of disease of 30,000 to 50,000 cases is most likely an underestimate.
It first appeared in Australian territory in 1995 in the Torres Strait islands. It resurfaced in the Torres Strait again in 1998 and for the first time it appeared on the Australian mainland at Cape York Peninsula. It appeared again in the Torres Strait in 2000, 2001 and 2005 and on the Cape York Peninsula in 2004.
Then silence – the virus seemed to disappear until Feb this year when cases of JEV were detected and confirmed in commercial piggeries in Vic, NSW, and Qld. In March 2022 cases were confirmed in piggeries in SA and the NT government confirmed JE positive results in feral pigs in the West Daly region. On the 4th March Australia’s acting Chief medical Officer declared the JEV situation a Communicable Disease Incident of National Significance
As of 29th June, there are 39 human cases of JEV in Australia – 29 confirmed and 10 probable. There have been 5 deaths.
So why has this virus appeared now? Why did it appear for the first time in the South-east of the country >2500km from its last known incursion? How did it get here and what happens next? This presentation will examine these questions and outline some of the strategies we can use to navigate yet another episode of viral emergence.