Mosquito-borne infection Ross River Virus detected in Perth's southern suburbs, Kwinana

Ross River virus has been detected in Perth’s southern suburbs for the first time this year in a worrying sign the warmer climate will trigger a dramatic rise in mosquito-borne infections.

The virus was detected in mosquitoes at The Spectacles in the City of Kwinana through WA Health’s mosquito disease surveillance program.

Kwinana mayor Peter Feasey said the spike in virus activity was likely the result of warmer water, which favours mosquito breeding.

He said the city was undertaking its own mosquito management in areas with a “recognised risk of Ross River virus activity” but reminded residents and travellers alike to take their own precautions to avoid mosquito bites over the coming month.

“During warm weather mosquitoes are most active at dawn and early evening, which is also when people are likely to be spending more time outside,” Mr Feasey said.

“It is not realistic to rely on mosquito management programs alone to control all mosquitoes.”

The last warning from WA Health was in August last year, when the virus was detected in mosquitoes in the South West for the first time in two years.

Ross River Virus is endemic in Australia, with outbreaks most commonly between January and May.

There is currently no vaccine or targeted treatment for the virus and can only be diagnosed by blood test.

Symptoms include painful or swollen joints, sore muscles, skin rash, fever, fatigue, and headaches.

These can last for weeks to months, but most patients recover from RRV disease in three to six months.

The only way to diagnose the disease is by visiting your doctor and having a specific blood test.

“People need to be actively protecting themselves from mosquito bites,” Mr Feasey said.

The Spectacles is 360ha of wetlands and bushland, with a recent survey finding at least 45ha in the northern Spectacles wetland will need larvicide treatment due to high concentrations of mosquito larvae.

The City of Kwinana’s mosquito management group is planning a trial aerial treatment, with the date to be determined based on helicopter contractor availability, larval activity, and environmental and meteorological factors.

To protect against RRV, WA Health and the City of Kwinana are advising the following precautions:

• Avoid outdoor exposure, particularly at dawn and in the early evening
• Wear protective (long, loose-fitting, light-coloured) clothing outdoors
• Apply an effective personal mosquito repellent containing diethyltoluamide (DEET), picaridin or Oil of Lemon Eucalyptus (OLE), also known as PMD, evenly to all areas of exposed skin and always follow the label instructions
• Remove water holding containers from around the home and garden to ensure mosquitoes do not breed in your backyard
• Use mosquito coils, mosquito lanterns and apply barrier sprays containing bifenthrin in patio and outdoor areas
• Ensure infants and children are adequately protected against mosquito bites, preferably with suitable clothing, shoes/socks, bed nets or other forms of insect screening
• Ensure insect screens are installed and in good condition on houses