Lismore and Northern Rivers residents are urged to protect themselves from mosquito bites this summer after the earlier-than-expected detection of two mosquito-borne viruses that can cause brain swelling.

Robin Auld, Associate Director of North Coast Population and Public Health, said these detections so early in the summer season were concerning.

NSW Health’s routine surveillance in Western NSW at Cowra detected Kunjin virus through a sentinel chicken blood sample on 20 November 2025.

Meanwhile, Horsham Rural City Council region in Victoria recently detected Japanese Encephalitis virus in a sample of mosquitoes, which is the first of the 2025/2026 season.

Mr Auld said that while there have been no detections in Northern NSW, it is important to take precautions.

“Mosquito numbers will likely increase with warmer weather, and we remind everyone in the region to protect themselves against mosquito bites, which can cause diseases such as Japanese Encephalitis and Murray Valley Encephalitis, and infection with Kunjin virus, Ross River virus and Barmah Forest virus,” Mr Auld said.

“There are now 60 NSW Local Government Areas that are considered to be at higher risk of Japanese Encephalitis virus. Residents and travellers to Lismore, Richmond Valley and Kyogle LGAs should take particular care to avoid mosquito bites.

“There is a safe, effective and free vaccine to protect against Japanese Encephalitis (JE). This vaccine is free to anyone who lives or routinely works in Lismore, Richmond Valley and Kyogle, and for people who work in some other high-risk occupations.”

JE vaccine is available through General Practitioners, Aboriginal health services and pharmacists. People who meet the eligibility criteria should make an appointment ahead of time and let the provider know it is for the JE vaccine. These providers may require a few days’ notice so they can order the vaccine and may charge a consultation fee.

A booster dose may be recommended for some people with an ongoing risk of exposure, one to two years after completing their primary course.

Other than the JE vaccine, there is no vaccination or specific treatment for Kunjin virus or other mosquito-borne diseases in Australia. The best way to avoid infection is to avoid being bitten by mosquitoes, which are more active between dusk and dawn. 

To prevent mosquito bites:

• Apply repellent to exposed skin. Use repellents that contain DEET, picaridin, or oil of lemon eucalyptus. Check the label for reapplication times
• Re-apply repellent regularly, particularly after swimming. Be sure to apply sunscreen first and then apply repellent
• Wear light, loose-fitting long-sleeve shirts, long pants, socks and covered footwear
• Avoid going outdoors during peak mosquito times, especially dawn and dusk
• Use insecticide sprays, vapour dispensing units and mosquito coils to repel mosquitoes (mosquito coils should only be used outdoors in well-ventilated areas)
• Cover windows and doors with insect screens and checking there are no gaps
• Remove items that may collect water such as old tyres and empty pots from around your home to reduce the places where mosquitoes can breed
• Use 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
• Use an infant carrier draped with mosquito netting to protect infants aged less than three months, secured along the edges
• While camping, use a tent that has fly screens to prevent mosquitoes entering or sleep under a mosquito net.

Information on eligibility for a free JE vaccine is available at Japanese encephalitis vaccination.

Mosquito borne diseases cannot be transmitted directly between humans or from any other animal.

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