(Diagram: Queensland Health)
January 24, 2025
The Queensland DPI and Darling Downs Health have issued alerts after cases of Japanese encephalitis were detected recently in Queensland, NSW and Victoria.
A Townsville resident who visited Yelarbon, in the Goondiwindi region, was diagnosed with Japanese encephalitis earlier this month and has been receiving treatment in Townsville Hospital.
This is the first detection of Japanese encephalitis virus (JEV) in a human in Queensland since 2023.
In Victoria, a person was also diagnosed JEV recently, while in NSW the detection was made in feral pigs.
There have been no detections in Queensland animals since 2022.
JEV can cause reproductive issues in pigs and neurological signs in horses, such as lack of co-ordination, difficulty swallowing and impaired vision.
In humans, it is usually a mild disease but in rare cases can cause very serious complications.
A Darling Downs Health spokesperson said JEV was a flavivirus related to dengue, yellow fever and West Nile viruses that can be spread by some, but not all, types of mosquitoes.
“JEV infection is preventable through vaccination and avoidance of mosquito bites,” Darling Downs Public Health Physician Dr Mikaela Seymour said.
Less than 1 per cent of people infected with JEV usually develop any symptoms of a disease; those who do may get a fever and headache, or abdominal pain and vomiting in children.
However, an very rare cases, acute encephalitis (inflammation of the brain) can occur. This severe disease can include a sudden onset of high fever and chills, severe headache, neck stiffness, disorientation, convulsions, paralysis and coma.
According to Queensland Health, in these severe cases, approximately one-third of patients die and one-third are left with permanent disabilities.
Free vaccination against JEV is available to at-risk groups and locations around Queensland – including residents in both the South and North Burnett council areas.
Free vaccinations are also available for people who work at or live near a piggery, pork abattoir or pork rendering plant; farm workers and their families (including children aged two months and older); transport workers; veterinarians and others involved in the care of pigs; pig doggers and hunters; and personnel who work directly with mosquitoes through surveillance, control or management.
In addition to vaccinations, community members should continue mosquito-safe behaviours such as wearing light colours, long sleeves and using insect repellent when outdoors and mosquito screens indoors.
A DPI spokesperson emphasised that Japanese encephalitis was a notifiable disease in Queensland.
Anyone who suspects an animal is showing signs of the disease must report it to either a local veterinarian or call the Emergency Animal Disease hotline on 1800-675-888.
The most common clinical signs in pigs are abortions, mummified or malformed foetuses and stillborn or weak piglets.
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