NSW Health can confirm one highly probable case of Japanese encephalitis virus (JEV) in a NSW resident, and is warning the public to be vigilant and safeguard themselves against mosquito bites.
The person is in ICU in a stable condition. They are a resident in the NSW-Victoria border region.
Several more patients in NSW are undergoing further testing, and more cases are expected to be confirmed over coming weeks.
Locally acquired cases of JEV have never previously been identified in NSW in animals or humans. JEV is usually only found in far northern Australia and neighbouring countries.
JEV can cause severe neurological illness with headache, convulsions and reduced consciousness in some cases.
There is no specific treatment for JEV.
JEV is a viral illness spread by mosquitoes. It can infect animals as well as humans, and has been confirmed in samples from a number of pig farms in regional NSW.
The virus cannot be transmitted between humans, and it cannot be caught by eating pork or pig products.
Dr Marianne Gale, NSW Health Acting Chief Health Officer, said the best way to avoid infection is to avoid being bitten by mosquitoes which are most active between dusk and dawn.
“NSW Health is cautioning people undertaking outdoor activities such as camping and fishing to carefully consider their plans. This is especially important for people planning activities near waterways or where mosquitoes are present, particularly the Murray River and its branches,” Dr Gale said.
“People should be particularly vigilant given the recent wet weather conditions, which have led to very high mosquito numbers that may increase further in the coming days and weeks.”
NSW Health is working closely with the NSW Department of Primary Industries and other state and territory agencies to determine the extent to which the virus is circulating, through animal testing and mosquito monitoring.
Mosquito control activities are being carried out in the vicinity of farms where pigs are confirmed to have been infected by JEV and NSW Health is arranging vaccination of workers on affected farms.
Simple actions you can take to avoid mosquito bites include:
For further information on mosquito-borne disease and ways to protect yourself go to
Vector-borne diseases - Resources.
Fact sheets on specific mosquito-borne diseases, including Japanese encephalitis Ross River virus and Barmah Forest virus, are available at
Vector borne disease fact sheets.