A case of Murray Valley encephalitis (MVE) virus infection, which is very rare in WA, has sadly resulted in the death of a child from the West Kimberley.
The case was potentially exposed to infected mosquitoes in the West Kimberley region which has recently been identified as an area of MVE concern, following the Kimberley floods.
The child had been receiving care in a Perth hospital.
This is the second case of MVE reported in WA since 2018.
Nationally, there have been 8 cases of MVE reported in 2023, to date.
Department of Health’s Director of Communicable Disease Control, Dr Paul Armstrong said the case follows recent MVE virus detections in mosquitoes and sentinel chickens in parts of the Kimberley and Pilbara regions where increased surveillance continues.
“We urge these communities to do everything they can to protect themselves against mosquito bites as there is no vaccination or specific treatment for Murray Valley encephalitis,” he said.
“In young children, fever might be the only early sign of infection. Parents should see their doctor or local health service if concerned, particularly if their child experiences drowsiness, floppiness, irritability, poor feeding, or general distress.”
“People can minimise the risk of infection by taking measures to avoid being bitten by mosquitoes especially when they are most active between dusk and dawn.
“Avoiding mosquito bites will also protect against other mosquito-borne infections including Japanese encephalitis and Kunjin viruses.”
While the risk of being infected and becoming unwell is low, the illness caused by MVE can be severe and even fatal.
Dr Armstrong said initial symptoms include fever, drowsiness, headache, stiff neck, nausea and dizziness.
“People with these symptoms should seek medical advice as soon as possible,” he said. “In severe cases, people may have seizures, lapse into a coma, be left with permanent brain damage or die.
Dr Armstrong said significant rainfall and flooding has created ideal breeding conditions for mosquitoes. Together with the detection of MVE in the region means that the risk of infection this year may be higher than previous years.
Mosquitoes may carry viruses that can make people seriously ill. Fight the Bite (HealthyWA) – take the following simple steps to avoid being bitten:
- Cover up while outside – wear loose, long-sleeved, light-coloured clothing, particularly at dawn and dusk when mosquitoes are most active.
- Ensure infants and children are adequately protected against mosquito bites, preferably with suitable clothing, shoes/socks, bed nets or other forms of insect screening.
- Apply mosquito repellent, containing picaridin, DEET or oil of lemon eucalyptus (OLE – also known as PMD), evenly to all areas of exposed skin. Read the instructions to find out how often you should reapply repellent.
- Mosquito wristbands and patches are not recommended as there is no evidence that these provide good protection against mosquito bites.
- Avoid outdoor exposure, particularly at dawn and early evening.
You can also limit the number of mosquitoes in and around your home by:
- Cutting your grass often and keep it short to minimise mosquitoes seeking shelter around your home.
- Applying a residual surface spray (containing bifenthrin) to outdoor walls, patios etc where mosquitoes might land – this will kill them. You can buy these products from hardware stores.
- Removing water holding containers from around the home and garden to ensure mosquitoes do not breed in your own backyard.
- Ensuring insect screens are installed and in good condition on houses and caravans.
- Using mosquito nets and mosquito-proof tents if sleeping outside.
- Using mosquito coils and mosquito lanterns.
MVE is a nationally notifiable disease.