UPDATE: Australians are on high alert as two deadly mosquito-borne viruses have been detected in Victoria and New South Wales (NSW) within the past week, prompting urgent health warnings. Health experts have confirmed the presence of Japanese encephalitis in a mosquito trap in Horsham, marking the first detection for the 2025-2026 season.
Victoria’s Chief Health Officer, Caroline McElnay, urges residents to take precautions, stating, “Anyone can be bitten by mosquitoes, but people living, working, or spending time outdoors in northern Victoria—especially near rivers—may be at higher risk.” Following this detection, authorities in NSW reported that 60 local government areas are now considered at heightened risk for this potentially fatal disease.
In addition to Japanese encephalitis, another virus, Kunjin, was identified in Cowra, NSW on November 20 during routine health checks of sentinel chicken blood samples. Stephen Conaty, Director of Health Protection for NSW Health, emphasized the need for vigilance, saying, “Mosquito numbers will likely increase with warmer weather. We remind everyone in NSW to protect themselves against mosquito bites.”
Japanese encephalitis virus (JEV) is transmitted through mosquito bites and can lead to severe health issues. While infections are rare, when they occur, they can result in serious brain inflammation. “About one in 250 cases can lead to a severe brain infection, which can be fatal,” warned epidemiologist Kishor Kumar Paul from UNSW Sydney. Notably, there is evidence of silent transmission in high-risk areas, with approximately one in ten individuals in certain locations testing positive for antibodies against JEV.
Symptoms of JEV can be mild, but severe cases may present with headaches, high fever, vomiting, convulsions, and even paralysis. The mortality rate for encephalitis cases is alarmingly high, underscoring the urgency of the situation.
Kunjin virus, a subtype of the West Nile virus, is also transmitted by mosquitos and poses a lower risk to humans, though it can still cause mild symptoms such as fever and joint pain. Dr. Paul noted that while Kunjin infections are typically less severe than JEV, the potential for complications remains.
Currently, there is no specific treatment for either virus; however, there is a vaccine available for Japanese encephalitis. Residents are encouraged to get vaccinated, particularly those with ongoing exposure risks. Unfortunately, no vaccine exists for Kunjin virus.
To mitigate risks, health officials recommend using mosquito repellents containing DEET, picaridin, or oil of lemon eucalyptus, especially during dawn and dusk when mosquitoes are most active. Residents should also eliminate standing water sources around their homes, which serve as breeding grounds for mosquitoes.
As this situation develops, residents in affected areas are urged to remain vigilant and take protective measures. The emergence of these viruses highlights the necessity for public awareness and proactive health strategies this summer.
Stay tuned for updates as health authorities monitor the situation closely. Share this urgent news with friends and family to ensure everyone is informed and protected.
