Japanese encephalitis: Health warning after deadly virus detected in Halls Creek
Health authorities are warning North West residents and travellers to protect themselves from mosquito bites after the potentially deadly Japanese encephalitis was detected in the Kimberley town of Halls Creek for the first time.
The Health Department’s sentinel chicken surveillance program, which acts as a warning system for mosquito-borne disease, has pinpointed evidence of prior infection with Japanese encephalitis virus within the flock in recent months.
Communicable disease control acting director Jelena Maticevic said JEV activity in the region posed “a significant risk” to human health.
“The Halls Creek result follows other evidence of JEV in the east Kimberley, including in Kununurra and Wyndham, as well as in Newman in the Pilbara, indicating an ongoing risk of JEV in the northern part of the State,” Dr Maticevic said.
“Most people infected with JEV will have no or very mild symptoms and will fully recover, however, a small percentage will go on to develop severe illness, including encephalitis (brain inflammation), which can lead to serious complications and death.
“Anyone who develops a sudden onset of fever, headache, neck stiffness, vomiting, seizures or disorientation should seek urgent medical attention.”
The nationally notifiable disease is transmitted through the bite of an infected mosquito.
So far no cases have been reported in WA, but seven people from across Australia have died from the virus since January 2021, out of 45 cases reported.
Children under five and older people are particularly vulnerable to developing more severe illness if they contract the disease.
Dr Maticevic said the department was working with local health services to roll out the JEV vaccine to eligible people living in high-risk areas, such as near wetlands and waterways where wild bird hosts and mosquitoes that can transmit JEV are prevalent.
“Avoiding mosquito bites is essential as it will also protect against other mosquito-borne diseases for which there is no vaccine, including Murray Valley encephalitis (MVE),” Dr Maticevic said.
A significant increase in the activity of flaviviruses, including MVE, JEV and Kunjin, has been detected across much of the State through the department’s mosquito-borne disease surveillance program, including recent detections of flaviviruses in the Mid West and Wheatbelt regions.
Recent significant rainfall and flooding in the Kimberley has created ideal breeding conditions for mosquitoes across seasonal wetlands. Waterbirds and pigs play an important role in the transmission cycle, passing the virus back to biting mosquitoes.
Japanese encephalitis was first detected in the Pilbara in February.
People are urged to apply effective insect repellent and to cover up with loose, long-sleeved clothing — particularly at dawn and dusk when mosquitoes are most active — to avoid being bitten.