Japanese Encephalitis in Australia: What You Need to Know

Japanese encephalitis (JE) is a mosquito-borne viral infection that poses a significant health concern in Australia. The disease is caused by the Japanese encephalitis virus (JEV), primarily transmitted to humans through bites from infected Culex mosquitoes. While many JEV infections are asymptomatic, a small percentage can develop severe complications, including encephalitis, which may result in permanent brain damage or death.

Recent Case in NSW

In early 2025, New South Wales (NSW) reported its first JE case of the summer. A man from southwestern NSW was hospitalized after contracting the virus, likely during a holiday in the Murrumbidgee region in late December or early January. This case, along with recent detections of JEV in pigs and mosquitoes across NSW, Victoria, and Queensland, highlights the virus's expanding reach and increased risk, especially for rural residents.

Common Symptoms

Most people infected with JEV do not develop symptoms, but for those who do, the illness can range from mild to severe. Common symptoms include:

• Fever

• Headache

• Nausea and vomiting

• Muscle aches

• Fatigue

• Confusion or disorientation (in severe cases)

• Seizures (more common in children)

• Coma (in rare, life-threatening cases)

Prevention & Vaccination

With JE cases increasing, health authorities recommend mosquito bite prevention strategies such as:
✔️ Using insect repellents with DEET or Picaridin
✔️ Wearing long-sleeved clothing outdoors
✔️ Sleeping under mosquito nets in high-risk areas
✔️ Eliminating standing water to reduce mosquito breeding