Australian health authorities have issued a warning regarding increased precautions against mosquito bites after the detection of Japanese encephalitis (JE) in New South Wales. This development has raised concerns about the virus's potential spread across inland Australia. Communities in southern NSW are advised to protect themselves following a probable human case of JE in the Riverina region and the detection of the virus in sentinel chickens, which serve as an early warning system.
Japanese encephalitis is a mosquito-borne virus capable of causing severe neurological illness. Symptoms may include headache, confusion, convulsions, and reduced consciousness. In some instances, the virus can be life-threatening.
NSW Health is investigating a probable case of JE involving a man in his 60s, believed to have been exposed in the Riverina region in late December. The warning was extended after the virus was detected in the Upper Lachlan Shire, near Goulburn, via a sentinel chicken blood sample collected in early January. Health officials indicate that this detection suggests the virus is circulating in the area.
Recent heavy rainfall in NSW has increased mosquito populations, raising the risk of disease transmission. Sentinel chickens are utilized nationwide as an early warning system, as they can contract mosquito-borne viruses without exhibiting illness, thus alerting authorities to viral activity before human cases emerge.
Alison Nikitas, Director of Public Health for Murrumbidgee and Southern NSW Local Health Districts, stated that the geographic spread of detections necessitates alertness across inland regions. She advised individuals living or working in high-risk areas to protect themselves by avoiding mosquito bites and seeking vaccination. Nikitas emphasized the absence of specific treatment for JE, highlighting the importance of awareness regarding the elevated risk. A safe and effective vaccine against JE is available free of charge to eligible individuals, including residents and routine workers in inland regions, as well as those in specific high-risk occupations.
Japanese encephalitis was initially detected in mainland Australia in 2022, indicating an expansion of the virus's established range. Health authorities have since warned that flooding, warm weather, and increased mosquito activity can elevate transmission risk, particularly in rural and agricultural sectors.
The JE vaccine is accessible via general practitioners, Aboriginal health services, and pharmacists. Authorities encourage eligible Australians to obtain vaccination promptly. Health officials emphasize that despite the rarity of human cases, early detection and prevention are crucial for mitigating serious illness, especially as mosquito populations increase in warmer periods. Individuals meeting vaccination eligibility criteria should schedule an appointment with their GP. Those vaccinated over a year ago should consult their healthcare provider regarding potential booster doses.
Mosquito Bite Prevention Recommendations
- Apply repellent to exposed skin. Use repellents containing DEET, picaridin, or oil of lemon eucalyptus. Check labels for reapplication times and ensure safety for children. Most skin repellents are safe for children aged three months and older. Reapply repellent regularly, particularly after swimming. Apply sunscreen first, then repellent.
- Wear light, loose-fitting long-sleeve shirts, long pants, socks, and covered footwear.
- Avoid outdoor activities during peak mosquito times, especially dawn and dusk.
- Use insecticide sprays, vapor dispensing units, and mosquito coils to repel mosquitoes (coils should only be used outdoors in well-ventilated areas).
- Cover windows and doors with insect screens and check for gaps.
- Remove items that collect water, such as old tires and empty pots, from around homes to reduce mosquito breeding sites.
- Protect infants under three months by using an infant carrier draped with mosquito netting, secured along the edges.
- While camping, use a tent with fly screens or sleep under a mosquito net.