More than 150 residents of Wodonga, Wangaratta and Indigo council areas are being sought for a survey on a mosquito-borne virus that resurfaced in Victoria this year, for the first time since 1974. The Victorian health department is conducting the study which will examine the spread of Murray Valley encephalitis virus. It was detected in humans and mosquitoes in the state earlier this year after nearly five decades of absence. Ovens Murray public health unit operational director Mick Enright said that gap in cases meant there was a lack of underlying data about the brain-attacking virus and its prevalence in Victoria. "This (study) will help us understand the risk in our area and help us with our prevention activities," Mr Enright said. There are 78 participants being sought from Wodonga, 53 from Wangaratta and 30 from Indigo. To be involved, candidates are required to attend a Dorevitch pathology clinic in Wodonga or Wangaratta and fill out a questionnaire and then have a blood sample taken which will be analysed for Murray Valley encephalitis. "We're not looking for people that know they have had it, we're just looking at the general population to detect whether they may have it without knowing in the past," Mr Enright said. He said that unlike Japanese encephalitis there was no vaccine for the Murray Valley variant. "So the best way to avoid Murray Valley encephalitis is to avoid mosquito bites, everyone's at risk of it if they're outdoors and not covering up," Mr Enright said. "The best way to avoid it is prevention - cover up with long clothes, use insect repellent with DEETs or picaridin in it, make sure you're catering for the vulnerable people like children as well." Mr Enright said the results of the study are expected to be known by February and it was planned to publish the outcome. Surveys are also being done in communities along other sections of the Murray River in Victoria. Thurgoona apprentice mechanic Dylan Meyer was one of the unfortunate people to have suffered Murray Valley encephalitis earlier this year. He told The Border Mail last week of his battle to overcome it and other mosquito-borne viruses after being bitten while on a Murray River camping trip in March.