Two samples of mosquitoes collected in the county last month tested positive: in the 22000 block of Ash Street in Woodburn and in the 6000 block of Tanager Boulevard off West Washington Center Road in northwest Fort Wayne.
As part of the county’s ongoing mosquito control program, four seasonal technicians set traps and gather samples throughout the county on a weekly basis, said Dave Fiess, director of vector control and environmental services for the health department.
The samples are then sent to the Indiana State Department of Health laboratory to be tested for West Nile virus and Eastern equine encephalitis.
County officials began trapping and testing mosquitoes in July, just a few weeks after the state announced the first mosquitoes to test positive for West Nile virus this season had been found in Orange County, Fiess said.
Recent rains brought some relief to drought-stricken northeast Indiana, along with a new crop of nuisance mosquitoes. But the primary carrier of West Nile virus is not the nuisance mosquito, but the culex mosquito, Fiess said.
The culex mosquito thrives in hot and dry weather and is a primary carrier of both West Nile virus and Eastern equine encephalitis. The breed prefers “nasty, dirty” water for breeding purposes, as opposed to the common nuisance mosquito, which prefers cleaner water, Fiess said.
The most effective way to prevent the spread of the West Nile virus is to eliminate breeding areas and to take precautions against getting bit by mosquitoes, Fiess said.
“The best thing residents can do is look around their properties and eliminate any standing water and flush out birdbaths,” Fiess said.
Many people think association ponds are to blame for providing breeding water for mosquitoes, but that is not usually the case, Fiess said. It’s the water-filled ditches and standing water trapped in old tires or containers on private properties that are the primary breeding source, he said.
Last year – because of limited resources and the possibility of increased resistance to the chemical – the department decided to cease routine insecticide spraying meant to eliminate mosquitoes, breeding sites and larvae. In 2010, the department sprayed 452 miles over seven nights at a cost of $10,870.
The staff now focuses on primary prevention measures, such as education, source reduction and larviciding, Fiess said.