DEADLY VIRUS

MURRAY Valley encephalitis (MVE) has been detected in Kununurra mosquitoes for the first time this wet season. The Department of Health has urged people living and holidaying in the north of WA to take extra care against mosquito bites, following the detection of the mosquito-borne disease.

Medical entomologist Michael Lindsay said the Department’s surveillance program (undertaken by The University of WA) had detected activity of MVE virus in Kununurra. “MVE is a fairly rare disease but can be fatal or cause severe symptoms, so it is important that people take precautions to avoid mosquito bites,” he said.

“Initial symptoms of MVE include fever, drowsiness, headache, stiff neck, nausea and dizziness and people experiencing these symptoms should seek medical advice quickly. “In severe cases, people may experience fits, lapse into coma, may be left with permanent brain damage or die.

“In young children, fever might be the only early sign, so parents should see their doctor if concerned, particularly if their child experiences drowsiness, floppiness, irritability, poor feeding or general distress.” Dr Lindsay said people most likely to be affected by MVE virus were newcomers to affected regions, such as babies, young children, tourists or new employees, but anyone experiencing these symptoms should seek medical advice quickly.

  “Wet season activity of mosquito-borne viruses now appears to be well underway in the north, with 13 cases of Ross River virus disease also reported from across the Kimberley since January,” he said. There are no specific cures or vaccines for MVE or Ross River virus, so it is very important that people take care to prevent being bitten by mosquitoes. The warning particularly applies to people living, visiting or camping near swamp and river systems during the evening and night throughout the north-east Kimberley and other mosquito-prone areas of the region.

However, the viruses may be active elsewhere in the Kimberley, especially where mosquitoes are abundant. Recent high tides along the Kimberley coast are likely to result in a substantial increase in biting mosquitoes in coastal areas during the next week. This is in addition to the freshwater breeding sites associated with wet season rainfall.

“Controlling mosquitoes in most rural regions of WA is generally not possible because of the large size and inaccessibility of natural mosquito breeding habitat,” Dr Lindsay said. People do not need to alter their plans to visit the Kimberley as a result of this warning. 

However, it is important to avoid mosquito bites by taking a few simple steps, such as:

• Avoiding outdoor exposure from dusk and at night in all 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.  Most natural or organic repellents are not as effective as DEET or picaridin;

• Ensuring insect screens are installed and completely mosquito-proof. Use mosquito nets and mosquito-proof tents; and

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