15 March 2023

Mosquito warning as virus spreads to the Pilbara region

Residents and travellers to the Pilbara are being urged to protect themselves against mosquito bites, following the spread of Murray Valley encephalitis (MVE) virus into the region.

The Department of Health warns that MVE virus has now been detected in sentinel chicken flocks in the Pilbara, following earlier detections in the east Kimberley. Sentinel chicken flocks are used by the Department to monitor and provide an early warning system for mosquito-borne virus activity.

MVE virus activity occurs in the Kimberley most years following wet season rainfall; however, this year has seen virus activity move further south. There have not been any human cases of MVE so far, this wet season.

WA Health’s Managing Scientist – Biological Hazards Dr Andrew Jardine said that MVE was only transmitted by mosquitoes.

“We want people in the Kimberley and Pilbara to be on alert, protect themselves and avoid mosquito bites.

While the risk of being infected and becoming unwell is low, the illness caused by the virus can be severe and even fatal,” he said.

Dr Jardine 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.”

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.

Dr Jardine said that recent significant rainfall and flooding in the Kimberley and parts of the Pilbara had created ideal breeding conditions for mosquitoes across extensive seasonal wetlands, increasing the risk of being exposed to MVE and a range of other local mosquito-borne viruses.

 “It is now more important than ever to take measures to prevent mosquito bites.”

The Department is carrying out enhanced mosquito-borne disease surveillance activities in the Kimberley and Pilbara to monitor any risk to public health.

To protect against mosquito bites:

  • if possible, avoid being outdoors at dawn and early evening
  • wear long, loose-fitting, light-coloured clothing outdoors
  • apply an effective personal mosquito repellent containing diethyltoluamide (DEET), picaridin or Oil of Lemon Eucalyptus (OLE, also known as PMD) evenly to all areas of exposed skin and always follow the label instructions
  • ensure insect screens are installed and in good condition on houses and caravans
  • use mosquito nets and mosquito-proof tents if sleeping outside
  • use mosquito coils and mosquito lanterns and apply barrier sprays containing bifenthrin in patio and outdoor areas around houses
  • ensure babies and children are wearing suitable clothing, shoes/socks, and use bed nets or other insect screening
  • keep grass/weeds and other vegetation short
  • remove water holding containers from around the home and garden to ensure mosquitoes do not breed in your backyard.

Visit HealthyWA for more information about mosquito prevention.