WA Health's sentinel chicken and mosquito surveillance programs have detected flavivirus activity, including Murray Valley encephalitis (MVE) virus, in the Pilbara and Kimberley for the first time this wet season.
Department of Health Medical Entomologist, Dr Abbey Potter said both surveillance programs in northern WA act as an early warning system for mosquito-borne virus activity.
"The potentially fatal MVE virus has been detected in mosquitoes in the Pilbara," Dr Potter said.
"Flavivirus activity has also been detected in sentinel chickens in the east Kimberley, and further laboratory testing is required to identify which flavivirus is currently active."
Residents and visitors to the Pilbara and Kimberley regions are urged to protect themselves against mosquito bites at this time of increased risk.
Dr Potter said flaviviruses such as MVE virus can cause serious and potentially fatal disease.
"While the risks of becoming infected and unwell are low, the consequences can be devastating."
Mosquitoes in northern WA can also transmit Japanese encephalitis (JE) virus, for which a vaccine is available. All Kimberley residents can currently access this vaccine free of charge.
For all other mosquito-borne diseases, including MVE, the only way to prevent infection is to avoid being bitten by mosquitoes.
The Repel, Prevent, Protect program rolled out in 2025, includes free mosquito repellent in key locations such as the Pilbara and Kimberley, where the risk of mosquito bites is highest.
Early medical attention remains critical in achieving the best outcome for people who are experiencing symptoms and may be infected.
Initial symptoms of infection may include:
- severe headache
- difficulty speaking or confused speech
- fever
- drowsiness or confusion
- stiff neck
- nausea and vomiting
- dizziness.
People experiencing these symptoms should seek medical care as soon as possible.
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, seizures, floppiness, irritability, poor feeding or general distress.
In severe cases, individuals may experience seizures, coma, permanent brain damage or death.
Community members can protect against mosquito bites by following these steps:
Cover up:
- Wear long, loose-fitting, light-coloured clothing.
- Dress children appropriately (including protecting feet) and use pram netting.
- Ensure insect screens are installed and in good condition on houses and caravans.
- Use mosquito nets and mosquito-proof tents if sleeping outside.
Repel:
- Apply an effective personal mosquito repellent containing diethyltoluamide (DEET), picaridin or Oil of Lemon Eucalyptus (also known as PMD) evenly to all areas of exposed skin and always follow the label instructions.
- Do not confuse Oil of Lemon Eucalyptus with eucalyptus oil and other botanicals that do not provide sufficient protection.
Clean up:
- Keep grass and other vegetation short to help prevent mosquitoes around your home.
- Empty or remove water holding containers around your home.
