BARABOO, Wis. -

A dead bird in Sauk County tested positive for West Nile virus, the county health department said.

The Sauk County Health Department said in a news release Monday that a dead crow found in Sauk County on Oct. 2 has tested positive for West Nile virus.

The health department said it's the first bird that's tested positive for West Nile virus in the county since surveillance for the mosquito-transmitted virus began May 1, 2016.

“The positive bird means that residents of Sauk County need to be more vigilant in their personal protective measures to prevent mosquito bites,” Cynthia Bodendein, health officer and public health director, said in a statement.

West Nile virus is spread to humans through the bite of an infected mosquito. Mosquitoes acquire the virus by feeding on infected birds.