WA Health issues warning after mosquito-borne Japanese encephalitis virus detected in Pilbara for first time

Health authorities are warning people in WA’s north to protect themselves after mosquitoes carrying the Japanese encephalitis virus were detected in the Pilbara for the first time. The deadly virus was identified last month in Newman via a surveillance program that tests chickens for signs of the disease. The find has prompted the WA Health Department to send an additional mosquito surveillance team to the region, with Communicable Disease Control senior medical advisor Jelena Maticevic warning the mosquito activity in the Pilbara was new and represented a significant risk to human health. “This is the first time evidence of (the virus) has been found in the Pilbara but follows on from recent evidence of Japanese encephalitis in the Kimberley,” Dr Maticevic said. “Most people infected will have no or very mild symptoms and will fully recover, however, a small percentage develop severe illness including an encephalitis (brain inflammation), which can lead to serious complications and death.” “Anyone who develops a sudden onset of fever, headache, vomiting, seizures or disorientation should seek urgent medical attention.” While the virus has been detected in the Pilbara and Kimberley no cases have yet been reported. Forty-five cases of Japanese encephalitis have been reported across Australia since January 2021, with seven of those resulting in the patient’s death. Less than one per cent of people infected with the virus will experience symptoms. Children under five years of age and elderly people are at a higher risk of developing more severe illness. A vaccine is available and Dr Maticevic said the department was working to expand eligibility to residents of highest risk areas. The virus spreads when mosquitoes bite an infected animal and then bite a human, with pigs and some water birds the most likely animals to infect mosquitoes. Humans cannot pass the virus to each other and cannot become infected by touching an animal or eating animal products. The department has also recently detected widespread evidence of Murray Valley encephalitis and Kunjin virus activity in the Kimberley and Pilbara regions. Residents and travellers in the north of WA have been urged to avoid being outside at peak times of mosquito activity, apply an effective repellent and to wear long, loose-fitting clothing to avoid being bitten.