NSW Health is reminding holiday makers as well as local residents to protect themselves from mosquito bites this summer season, following the recent detection of Japanese encephalitis virus and Murray Valley Encephalitis virus.

NSW Health's Executive Director of Health Protection Dr Jeremy McAnulty said mosquitoes thrive in warm conditions, increasing the risk of mosquito-borne illnesses such as Murray Valley encephalitis, Japanese encephalitis, Ross River and Barmah Forest viruses in parts of NSW.

“Each year from November to April, NSW Health undertakes surveillance across the state, to provide important information about when mosquito-borne disease risk is elevated," Dr McAnulty said.

“Japanese encephalitis (JE) virus has now been found in mosquitos in the Moree area, in the first results reported from the program this year.

Murray Valley Encephalitis (MVE) virus infection has also been detected in sentinel chicken flocks in Cowra and West Wyalong in samples collected in December 2024.

“JE virus was previously detected in mosquitoes in December 2024 in the Griffith area, and in feral pigs in the Narromine Shire local government area.

Both of these viruses can cause severe brain swelling (encephalitis) and even death. Symptoms of brain swelling include neck stiffness, disorientation, tremors, seizures, paralysis and coma.

“These detections indicate the risk for mosquito-borne virus transmission is widespread, particularly in the 55 NSW local government areas that are at higher risk of JE in the inland regions.

“I encourage anyone planning to spend time outdoors in these higher-risk areas to take steps to protect against mosquito bites."

For people who live or regularly work in these areas, JE vaccine is available through local General Practitioners (GPs), Aboriginal health services and pharmacists. Information on eligibility for a free JE vaccine is available on the NSW Health website.

People who meet the above criteria should make an appointment ahead of time and let them know it is for the JE vaccine. These providers may require a few days' notice so they can order the vaccine.

There have been no confirmed human cases of JEV acquired in NSW since October 2022.

There is no vaccine to protect against Murray Valley Encephalitis virus. Actions to prevent mosquito bites include:

• Applying repellent to exposed skin. Use repellents that contain DEET, picaridin, or oil of lemon eucalyptus. Check the label for reapplication times
• Wearing light, loose-fitting long-sleeve shirts, long pants and covered footwear. and socks
• Avoiding going outdoors during peak mosquito times, especially dawn and dusk
• Using insecticide sprays, vapour dispensing units and mosquito coils to repel mosquitoes (mosquito coils should only be used outdoors in well-ventilated areas)
• Covering windows and doors with insect screens and checking there are no gaps
• Removing items that may collect water such as old tyres and empty pots from around your home to reduce the places where mosquitoes can breed
• Using repellents that are safe for children. Most skin repellents are safe for use on children aged three months and older. Always check the label for instructions
• Protecting infants aged less than three months by using an infant carrier draped with mosquito netting, secured along the edges
• While camping, use a tent that has fly screens to prevent mosquitoes entering or sleep under a mosquito net

For further information on JE virus and ways to protect yourself visit Mosquito borne diseases.