The Jefferson County Health Department found samples of adult mosquitoes in De Soto and Crystal City that tested positive for the West Nile Virus. Those samples were collected Oct. 3, according to a written statement from the health agency.
In all, the Health Department has found four positive samples in the county this season. The other two samples were found in Hillsboro and unincorporated Fenton.
The mosquitoes that tested positive for the virus were found in surveillance traps the Health Department set up, said Judy Tufts, the Health Department’s emergency response supervisor.
She said there are 100 sites around the county with surveillance traps.
Tufts said the Health Department handles mosquito control treatments in De Soto. Crystal City has its own vector unit and handles its own mosquito control.
She said the mosquito season starts once temperatures rise above 70 degrees and stay there. That means the season normally starts around late May and early June and goes to early October.
Emergency response vector technician Scott Darrough said residents should continue taking measures to avoid mosquito bites and to prevent, or at least minimize, population growth in mosquitoes.
Some protection measures include using insect repellent containing 20-50 percent DEET or Picaridin, wearing light-colored clothing and removing standing water sources that can be sites for mosquitoes to lay eggs in, such as old tires, cans, buckets, flower pots or pools.