Authorities are urging people to be vigilant about mosquito-borne diseases after the first Victorian case of Japanese encephalitis this season was identified last month.
The case was detected in the Campaspe LGA, which included the flood-affected communities of Echuca and Rochester.
Heavy rains and flooding have made conditions favourable for mosquitoes, which can carry infectious diseases such as Japanese encephalitis, Murray Valley encephalitis, Ross River fever and West Nile virus (Kunjin strain).
"We're not surprised to see a case along the Murray River region this year," said Lucie Shanahan, executive director of public health at Albury-Wodonga Health.
"The virus appeared this far south for the first time last year, and ongoing monitoring across the last 12 months has indicated [it] was likely to still be around."
Ms Shanahan said JEV was such a new illness in this part of the country that many people aren't aware of how serious it can be.
"Our other common mosquito borne viruses — such as Ross River and Barmah Forest virus … can also have quite significant effects," she said.
Council surprised
Acting CEO of Campaspe Shire Council Tim Tamlin said he was surprised to learn of the case in the LGA because council had increased its mosquito surveillance following the floods under the Health Department's advice.
"We normally do about four traps per week, and we have been doing about six to eight so far and we haven't detected any disease in any of our traps," he said.
The mosquitoes are sent off for analysis and the health department has not yet found Japanese encephalitis in any of the samples across the state.
Mr Tamlin said the council noticed mosquito activity was highest in October and November but the numbers had dropped as the weather became drier.
He said the council would continue its surveillance and treatment of stagnant water and public spaces.
But he said the best control was to follow the government's campaign which included cleaning up stagnant water on private properties and wearing long, loose-fitting clothing the right insect repellent.
"You won't find me outside without my DEET [diethyltoluamide] sprayed all over me. It's just too high risk."
Mosquito-borne diseases can have lifelong effects
Most cases of JEV are asymptomatic, but in a small number of cases it can result in fever, headache, vomiting, disorientation and, in some instances, seizures.
Ms Shanahan said people should seek medical attention if they have those symptoms and they don't respond to normal treatments.
"Encephalitis acquired through mosquito bite can have lifelong implications and disability for people," she said.
Agriculture Victoria also warned horse and pig owners to protect their animals by controlling mosquito numbers and preventing bites.
Chief Veterinary Officer Dr Graeme Cook said that despite no reported animal cases in Victoria since last summer, it's reasonable to anticipate that JE may affect livestock again this season.
"Reducing mosquito breeding sites by removing stagnant water or fixing dripping or leaking taps and water troughs, is critical in reducing the risks of arbovirus."
