Infection hazard

New South Wales Health authorities are warning the public to take extra care after two potentially fatal mosquito-borne infections were discovered in the state's west.Japanese encephalitis (JEV) has been detected in mosquitoes around Moree in north-west NSW for the first time, with local GPs reporting a surge in vaccine appointments. That detection has come at the same time Murray Valley encephalitis has been found in chickens in Cowra and West Wyalong in the central west of the state.Hunter New England Health public health physician David Durrheim said the detection of JEV could be a worrying sign."What we're seeing is probably very widespread mosquito infection with this virus, and we need to take this very seriously," he said.Dr Durrheim said recent rain and hot weather across the state's north-west created perfect conditions for mosquito breeding, heightening the risk of large-scale infections.Last detected in humans in NSW in 2022, JEV cannot be spread from person to person but can cause severe brain swelling, and symptoms include stiffness in the neck, disorientation, tremors and seizures.Dr Durrheim said while roughly one in every 100 humans infected developed the disease, the effects could be life-threatening. "For about a third of them the disease can be fatal, and amongst the survivors, about a third of people are left with terrible neurological deficit," he said.NSW Health has advised those in the Moree region to remain extra vigilant for mosquitoes during peak hours like dusk and dawn.It has also urged people to wear long sleeves and insect repellent for extra protection.Rhonda Lang, manager of the Associate Medical Practice in Moree, said the centre had ordered an extra 50 doses of the vaccine to prepare for a rush of appointments."There's 29 [vaccination appointments] booked until next Thursday," she said."We ordered more vaccines from NSW Health because we anticipated that influx. "I think there'll be an initial burst of people wanting it, and then it'll probably trickle down to doctors raising it in consults in a month or so."Murray Valley encephalitis has also been detected in chicken flocks in the state's central west.The infections were found in a group of sentinel chickens in Cowra and West Wyalong after testing in December.NSW Health regularly tests several birds in towns across the state to manage the spread of encephalitis.While a vaccine is available for Japanese encephalitis, there is currently no protection available for the Murray Valley infection.Most people who are infected with the virus that causes Murray Valley encephalitis do not have any symptoms.
But for the small proportion who do, symptoms can include drowsiness and confusion, severe headaches, seizures and in some cases death.