Mildura Rural City Council is urging people to avoid getting bitten by mosquitoes, after Murray Valley Encephalitis virus was detected in the area.
The Victorian Health Department confirmed the positive test in mosquitoes yesterday.
It marks the first time a case of MVE virus has been found in Victoria in more than a decade.
In a statement, the council said it had begun treating the detection area.
It said people can help avoid being bitten by wearing long-sleeved, loose-fitting clothing, using repellents containing DEET and putting flyscreens on windows and doors.
MVE can cause rare but serious nervous system infections in humans, and can potentially be fatal.
There is no vaccine or effective treatment.
The council's Andrew Millen told ABC Wimmera Breakfast with Rebekah Lowe that the virus was picked up during a regular mosquito monitoring program.
"There may well be more cases [in people] out there and they will present to the relevant medical services as they develop symptoms," he said.
"They will do the appropriate tests. In most cases I would think it will not be MVE, just a mozzie bite that has become a bit red."
"I'm aware there are a couple of detections [in areas other than Mildura] and the department will release those sites and information as it sees fit."
The department is advising anyone with symptoms of MVE virus to seek urgent medical care.
Symptoms may include fever, headache, nausea, vomiting and muscle aches, although most infected people do not have symptoms. In serious cases, people can develop meningitis or encephalitis.
The Victorian detection has come one day after NSW Health detected the virus in Menindee, saying it was likely linked to the flooding currently making its way down the Darling River.
The Darling joins the Murray River not far from Mildura, which has only recently begun recovery from its own flooding situation which peaked in mid-December.
"The outbreak that was most prevalent was in 1974, and I believe we also had a detection in 2011 in the Mildura region," Mr Millen said.
