Murray Valley Encephalitis virus

Cape York residents are urged to take all precautions against mosquito bites, following the recent detection of Murray Valley Encephalitis (MVE) virus in mosquitoes at Weipa.

Torres and Cape Hospital and Health Service Public Health Medical Officer Dr Allison Hempenstall said this was the first detection of MVE virus in mosquitos at Weipa in more than10 years.

“The virus is spread by the bite of a mosquito and not from person to person,’’ she said.

“There is no vaccine against MVE virus and the best protection, as with all mosquito-borne infections, is to avoid being bitten in the first place.

“Everyone should use personal protective measures to avoid mosquito bites, especially young children and babies, and those visiting or camping near swamps, lagoons, dams and temporary pools of water in grassy areas.

“They should also take action to eliminate mosquito breeding sites on their properties.’’

Personal protective measures include:

• Wear light-coloured clothing, (long-sleeved shirts and long pants wherever possible to cover exposed skin).
• Use personal insect repellent containing DEET (di-ethyl toluamide) or Picaridin, which tend to last longer than other repellents, depending on the concentration. DEET and Picaridin are safe for use by pregnant women. Always follow the manufacturer’s directions. Repellents usually only protect against mosquito bites for up to four hours.
• Use long-lasting ‘surface’ or ‘cockroach’ insecticide spray in places where mosquitoes can hide.
• Use other mosquito protection devices such as electric zappers and mosquito coils.
• Install insect screens that are in good working order in your home and office. If not, sleep under a mosquito net day and night.
• Tip it, store it, throw it — tip out water from containers weekly, or dry store containers under cover and discard rubbish properly. Mosquitoes breed in containers that hold water.
• Remember, under the Public Health Act 2005, you can be fined by your local council if your home or yard promotes the breeding of mosquitoes.

Dr Hempenstall said although MVE virus circulated throughout Australia, it was more common in the Top End of the Northern Territory and north-west of Western Australia.

“But it can also occur in inland North Queensland and there has been one case of MVE virus so far this year in Queensland in the north-west region,’’ she said.

“The MVE virus is present during the wet and post-wet seasons from February to July, but with most cases being reported between March and May.’’

Infection with mosquito-borne diseases, such as MVE virus, may cause illness ranging from mild to very serious. Illness may include flu-like symptoms such as:

• pain in muscles and joints
• rashes
• headaches
• fever.

Symptoms can progress to drowsiness, confusion, seizures or fits (especially in young children) and in severe cases delirium, coma and death. Some who recover are left with ongoing problems such as deafness or epilepsy.

Anyone with the above symptoms should seek immediate medical advice. A blood test is available to test for recent or past MVE virus infection.

“And remember, even mosquito bites that do not transmit diseases can be harmful. Bites can be very irritating and itchy, causing some people to scratch them until they break the skin, leading to secondary infection,’’ Dr Hempenstall said.

To prevent skin infections from mosquito bites:

• try to avoid scratching the bite
• apply calamine lotion or another anti-pruritic preparation to bite areas to prevent itching
• keep affected limbs elevated
• wash hands before and after touching open wounds
• watch skin sores for signs of infection.

If the bite areas become inflamed, clean with soap and water at least once a day, apply an antiseptic lotion and keep covered with a dry dressing. Application of a cool compress (i.e. icepack wrapped in cloth) also can reduce inflammation. If skin sores become hot, red, swollen, or painful, see your doctor immediately.

Read more about Murray valley encephalitis on the Queensland Government website.