Health authorities issue warning on mosquitoes

Residents and visitors in the Murray Valley area of Victoria and South Australia, as well as the Bendigo area in Victoria, and in northern and central WA being warned to protect themselves against mosquitoes following new detections of Murray Valley encephalitis virus (MVEv) in areas in these states.

The disease has been detected in sentinel chickens at the lower Murray region of South Australia and Victoria as well as other sites in Victoria, and in northern and central WA. There have been no confirmed cases of MVEv in humans yet.

In NSW evidence of the Kunjin virus has been found in Bourke and Macquarie Marshes, the same areas where MVEv was found recently. The Kunjin virus has also been found in mosquitoes in Moama and Griffith in the Murrumbidgee LHN.

In WA the Kunjin virus has been detected in the Kimberley, Pilbara and Gascoyne regions. In addition, a large number of cases of Ross River virus disease have been notified in people from the Kimberley and Pilbara regions. Cases of Barmah Forest virus disease are also being notified from the Midwest region.

The Kunjin virus is typically found in some parts of northern Australia. Unusually high rainfall and flooding in southern parts of the country has allowed the virus to infect water birds that normally carry Kunjin virus and the mosquitoes that feed on them.

Usual symptoms of Murray Valley encephalitis  and the other virus diseases include severe headache, high fever, drowsiness, tremor and seizures. People experiencing such symptoms should seek urgent medical attention from their GP or their local hospital

Health authorities in the four states have said it is important for people to take mosquito warnings seriously.

“Although the vast majority of Kunjin infections do not show symptoms, Kunjin virus disease can be serious. Some people with the infection develop mild illness with fever, enlarged lymph nodes, rash, swollen and aching joints, headache, muscle weakness and fatigue. Some people with Kunjin virus disease may develop encephalitis, a severe brain infectionwhich requires treatment in hospital,” NSW Health official Dr Sandra McAnulty said.

Mosquitoes become infected by feeding on infected birds and can then bite a human and transmit the infection.

A copy of the NSW Health fact sheet on Kunjin Virus is at www.health.nsw.gov.au/factsheets/infectious/kunjin.html