The notification of two possible, yet to be confirmed cases of Murray Valley encephalitis (MVE) in the Barkly region within the past few days has prompted the issuing of a health advisory by the NT Department of Health.
"Murray Valley encephalitis is a potentially fatal disease transmitted by mosquitoes," the Centre for Disease Control's Alice Springs Co-ordinator, Dr. Teem-Wing Yip, said today.
"Although MVE is endemic to northern Australia the number of cases in an average year would seldom exceed two in the whole of the Territory. In the light of this week's two suspected cases we feel it important to remind people to protect themselves against the common banded mosquito (Culex annulirostris)which carries this very unpleasant disease."
Dr Yip said about one person in 1,000 bitten by infected mosquitoes will contract the disease, with those at the greatest risk being people with no prior exposure to the virus, including babies, young children, and tourists.
"However, cases have also been reported in long-term residents, and because of the disease's potential severity anyone experiencing the early symptoms of MVE should seek urgent medical attention."
Usual symptoms of the disease include severe headache, high fever, drowsiness, tremor and seizures, especially in young children, and in some cases the condition progresses to delirium and coma, leading to paralysis or brain damage.
"Despite best care, 1 in 4 people still die from this disease and another 1 in 4 will not make a full recovery," Dr Yip added, "and there is no specific treatment apart from supportive care."
Both MVE and the related Kunjin virus are endemic in the Barkly and Top End of the NT, with virus activity in sentinel chickens being detected each year. Testing of the sentinel chickens by the Berrimah Veterinary Laboratories has indicated MVE and Kunjin virus activity in the sentinel chicken flock in Tennant Creek in early March. As a result of the suspected cases additional mosquito control strategies are being implemented.
Taking precautions against being bitten by mosquitoes needs to be taken very seriously in the Barkly region and all regions throughout the NT until the end of July when virus activity is expected to return to a minimum.
The warning particularly applies to people visiting or living in rural areas within five kilometres of large coastal and sub-coastal flood plains and swamps and in seasonally flooded areas associated with creeks and rivers.
People can reduce their chances of getting bitten by avoiding these areas particularly just after sundown and for the first two hours of the night.
Precautions include:
- avoid outdoor exposure around dusk and at night, near rivers and areas of dense vegetation as well as other areas of high mosquito activity
- consider bifenthrin insecticide barrier treatments from pest control companies for use around residential grounds
- regularly search the yard for water pooling or containers holding water. Drain and store containers under cover, or turn over, dispose of or treat with methoprene insecticide pellets or liquid mosquito surface film
- use mosquito proof accommodation and camping facilities at night
- wear protective light coloured clothing with long sleeves, long trousers, and ankle protection with socks, between dusk and dawn in areas where mosquito bites are likely
- use a protective repellent containing 20% DEET or picaridin when outdoors at night in areas of mosquito activity, ensuring directions for use and application on the label are followed
- use other mosquito protection devices such as mosquito lanterns or insecticide pads or coils as a supplement to protective clothing in exposed situations such as patios or verandahs
- ensure children are adequately protected against mosquito bites.
"Self-protection and protection of young children and others who require care is important. Awareness of the disease and basic measures to avoid mosquito bites are the most important preventative measures," Dr Teem-Wing Yip stressed.
Media inquiries: Robin Osborne, Media Director, (08) 8999 2886 or 0488 692 781
Release date: 1 April 2011
