Japanese Encephalitis Causes Second Death in Australia's NSW

According to the World Health Organization (WHO), the Japanese encephalitis virus (JEV) is the leading cause of viral encephalitis in twenty-four countries. 

Since 2022, when Australia's government declared a Japanese encephalitis virus (JEV) outbreak of National Significance, infected mosquitoes have spread this flavivirus into most of the country. Pigs have also served as an amplifier host.

As of March 14, 2025, JEV cases and related fatalities have been confirmed in Queensland, New South Wales (NSW), South Australia, Victoria, Australian Capital Territory, Tasmania, Western Australia, the Northern Territory, and parts of the Torres Strait region.

Unfortunately, NSW Health today confirmed a second JEV death this year.

A man in his 70s, who may have acquired JEV while visiting the Murrumbidgee River region, died in early March 2025.

This is the second death from JE acquired in Australia's southeast area this year and the fourth since the virus was first detected in NSW.

Additionally, one probable case of JE infection has been identified in a man in northern NSW. He likely acquired the infection when travelling between Moree Plains, Tamworth, and Gunnedah shires. He is now recovering at home.

This is the fifth person infected with JE in NSW this season. 

NSW Health's Executive Director of Health Protection, Dr Jeremy McAnulty, said in a press release, "People need to take mosquito-borne infections seriously, especially as people start the clean-up from recent floods in an environment where mosquitos thrive."  

"Standing water, like that left after mass rainfall and floods, makes for ideal breeding grounds for mosquitoes. This increases people's risk of being bitten, especially if they're working outdoors," added Dr McAnulty.

As of March 2025, the WHO says safe and effective vaccines are available to prevent JE.

​In Australia, the JE vaccine is free for people who meet the eligibility criteria and is available through local General Practitioners, Aboriginal health services, and pharmacists.

In the United States, one JE vaccine (IXIARO) is U.S. FDA-approved, and the CDC recommends it for travelers visiting endemic areas in 2025.

Last year, about 650,000 people from the U.S. visited Australia, including the NSW's capital city, Sydney, with over 5 million residents. The vast majority are unprotected against JEV infections.

Furthermore, the CDC suggests other travel vaccines for Australians visiting this year. These vaccines are commercially offered at travel clinics and pharmacies in the U.S.