NSW and Queensland residents warned of mosquito-borne Japanese encephalitis virus

Health authorities have warned of a dangerous insect-borne virus after Cyclone Alfred’s extreme weather created ideal breeding conditions.

A potentially deadly virus was detected for the first time in Queensland’s capital as the state health authority issued warnings about the mosquito-borne disease in the wake of extreme weather conditions.

Japanese encephalitis virus (JEV) was detected in Hemmant, a suburb in Brisbane’s east, on Friday. It can cause severe neurological illness and even death, according to Queensland Health.

The health authority said routine mosquito surveillance programs detected the presence of JEV in Brisbane, adding the risk of human exposure could increase after recent flooding following Ex-Tropical Cyclone Alfred.

The recent warm and wet weather conditions have created an ideal breeding habitat for mosquitoes as health authorities sound the alarm for heightened disease risk. Picture: NewsWire/Tertius Pickard

Queensland Health’s chief health officer Dr Heidi Carroll said the Brisbane detection meant JEV increased mosquito surveillance is underway as a result of the increased risk of infection across a number of regions in Queensland.

“This latest detection is the first for Brisbane and tells us that more mosquito populations are likely carrying the virus. It’s critical that Queenslanders remain extra vigilant against mosquito bites across the state, no matter where they live,” Dr Carroll said.

“While most people infected with JEV experience only mild symptoms or no symptoms at all, those who do develop more serious symptoms may experience fever, headache, abdominal pain or vomiting, typically within five to 15 days of being bitten.”

Dr Carroll said it is “common” to see mosquito populations increase after wet and warm weather, which increases the risk of contracting mosquito-borne illness. She urged residents to focus on prevention measures to avoid getting infected by the virus.

The Japanese encephalitis virus is spread through bites from mosquitoes and is potentially deadly to humans. Picture: WHO

“I encourage all Queenslanders to adopt personal protective measures to avoid mosquito bites such as using repellents containing DEET, picaridin or oil of lemon eucalyptus, wearing long, loose-fitting, light-coloured clothing, and using mosquito coils (outdoors) and insecticide vaporisers,” she said.

“Pooled water makes ideal conditions for mosquitoes to breed, so it’s important that everyone makes sure to, wherever possible, remove standing water around their home following recent rain and flooding.”

Queensland recorded its first locally-acquired human case of JEV since 2022 in January this year. This case is likely to have been infected in the Darling Downs region, near Goondiwindi.

Queenslanders have been urged to check their vaccination status and take protective measures against mosquitoes. Picture: NewsWire/Tertius Pickard

JEV has been detected in mosquito populations in the Darling Downs and Wide Bay regions, as well as in mosquito and feral animal populations in other parts of the state.

“Mosquitoes become infected with JEV after they bite infected pigs or wading birds. JEV can then be spread to humans through the bite of an infected mosquito,” Dr Carroll said.

“Piggery workers are at risk of exposure to JEV due to their work. It’s very important if you work at, live near or have a planned visit to a piggery, to take advantage of free vaccination against JEV. Transport workers, veterinarians or others involved in the care of pigs are also eligible.”

The JEV vaccination is available at selected GPs, pharmacies and community immunisation providers. The vaccine itself is free for eligible Queenslanders.

The detection comes after NSW authorities urged residents to take steps to avoid being bitten following the death of a man in his 70s last week.

NSW Health said the man likely acquired JEV while on a holiday in the Murrumbidgee region and marked the second death in the state this year.

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

“Standing water, like that left after mass rainfall and floods, makes for ideal breeding grounds for mosquitoes.”

Originally published as NSW and Queensland residents warned of mosquito-borne Japanese encephalitis virus