Ross River, Barmah Forest Viruses Alert For Holiday Period

Ruzanna Harutyunyan's picture

The Department of Health today reminded people to take care against mosquito bites following detection of both Ross River virus (RRV) and Barmah Forest virus (BFV) in mosquitoes found in the south-west of the State.

Department of Health Medical Entomologist Dr Michael Lindsay said the Department's surveillance program (undertaken by The University of Western Australia) had detected mosquitoes infected with both RRV and BFV, over recent weeks.

The number of reported cases of RRV disease in the South-West and Perth this spring and early summer is above average. Of 152 cases of RRV disease reported in WA since the start of October, 72 are from the South-West and 51 are from Perth. Smaller numbers have also been reported from the Kimberley, Pilbara and Midwest.

"The unseasonal rain, above average tides and mild start to summer means that mosquitoes are likely to be a bigger problem in some areas these holidays than is normally the case," Dr Lindsay said.

"At the moment, people in coastal communities in the South-West close to salt marshes or wetlands are likely to be at greatest risk, but the risk may spread inland and further south in coming weeks."

Residents on the south coast, including the Albany region, should also be prepared for an increase in mosquito numbers following unseasonal rain there earlier this month.

Dr Lindsay said mosquito management programs run by local governments and the Department of Health had been in place since September and were continuing in areas with a recognised risk of RRV and BFV.


"However, unfavourable environmental conditions can reduce the effectiveness of control methods, so people need to take their own precautions to avoid mosquitoes," he said.

Most of the types of mosquito that carry RRV and BFV in the South-West and Perth breed in natural environments but they can also breed in water-holding containers around houses and other buildings. People can help reduce RRV and BFV risks in their community by ensuring they are not breeding mosquitoes around their home or work place.

RRV and BFV infections cause painful or swollen joints, sore muscles, skin rashes, fever, chronic fatigue and headaches. Symptoms can last for weeks or months and the only way to properly diagnose the virus infections is by having a blood test. There are no specific cures or vaccines for these viral infections, so it is very important that people take care to prevent being bitten by mosquitoes.

Dr Lindsay stressed that people did not need to alter their holiday plans to the South-West as a result of this warning, but it is important to be aware of the risk and to avoid mosquito bites by taking a few simple steps, such as:

* avoiding areas of high mosquito activity;

* wearing protective (long, loose-fitting) clothing when outdoors;

* using a personal repellent containing diethyl toluamide (DEET) or picaridin. The most effective and long-lasting formulations are lotions or gels.

* ensuring insect screens are installed and completely mosquito-proof: using mosquito nets and mosquito-proof tents;

* ensuring infants and children are adequately protected against mosquito bites, preferably with suitable clothing, bed nets or other forms of insect screening.