The Polk County Health Department reported two dead crows have tested positive for West Nile Virus. These are the first birds that tested positive for West Nile Virus in Polk County since surveillance for the mosquito-transmitted virus began on May first. West Nile Virus is spread to humans through the bite of an infected mosquito. Mosquitoes get the virus by feeding on infected birds. Brian Kaczmarski, Public Health Director said that residents of Polk County need to be more vigilant in their personal protective measures to prevent mosquito bites. The Wisconsin Division of Public Health will continue surveillance for West Nile Virus until the end of the mosquito season. No additional testing of dead birds is done once a county has a bird test positive for West Nile Virus. Reporting of sick or dead crows, blue jays, or ravens is still encouraged.