‘Increased risk’: Queensland issues warning over mosquito-spread viruses after threat moves across border

Health authorities in one Aussie state have issued a major warning over viruses spread by mosquitos, less than a week after a similar issue across the border.

A wave of mosquitoes is causing alarm in another state as swampy conditions compound the airborne threat.

A week after NSW Health issued a warning about the bugs and feral pigs carrying Japanese encephalitis, Queensland authorities say recent heavy rains have amplified the need for repellent and full coverage clothing.

“Mosquito numbers always increase significantly in wet and warm weather, and Queenslanders need to be extra vigilant against bites starting now,” Queensland chief health officer Heidi Carroll said on Tuesday.

Areas of Brisbane received 80mm of rain last week, exacerbating the threat of mosquito diseases. Picture: NewsWire / Glenn Campbell

Health authorities have warned this wet and warm weather can lead to an increased number of mosquitos and a further risk of contracting diseases they spread. Picture: iStock

“With increased mosquito numbers comes increased risk of contracting mosquito-borne illnesses, such as Ross River virus and Japanese encephalitis,” Dr Carroll said.

Ross River virus is the most common mosquito-borne disease in Queensland and there is no vaccine or specific antiviral treatment. Symptoms include fever, headaches, rash, muscle and joint pain and fatigue.

Japanese encephalitis can be fatal - though only about 1 per cent of people develop more than mild symptoms.

Free vaccinations are available from the Queensland government for people who work with pigs or live or work in Indigenous communities.

Japanese encephalitis, which is spread by mosquitoes, can be fatal but the risk is very low. Picture: Supplied

“We’ve been notified by New South Wales health authorities that surveillance programs have identified JEV activity among feral pig populations and mosquitoes across the state, with some activity detected near the Queensland border,” Dr Carroll said.

“This means there is likely an increased risk of JEV in Queensland.

There have been no human Japanese encephalitis cases in Queensland since May 2022.

“Residents in the Far North, Darling Downs, South West and Wide Bay regions particularly need to be vigilant as this is where JEV has previously been detected in Queensland in recent years,” Dr Carroll said.

Heavy rain breeds mosquitoes. Picture: NewsWire / John Appleyard

Severe infections can result in permanent brain damage or death. People are being warned to apply mosquito repellents, use insecticide sprays and coils, avoid going outside during peak mosquito times of dawn and dusk, wear loose-fitting long clothes and covered footwear, and reapply repellent regularly, particularly after swimming.

Last week NSW authorities identified 55 inland local government areas at higher risk of Japanese encephalitis, after the virus was found in routine surveillance in Griffith and in feral pigs in Narromine Shire.

NSW residents can also get free vaccinations if they live or work in one of the 55 areas and regularly spend time outdoors, are homeless, living in a tent or caravan, or are a paid or volunteer flood rescue worker.