MADISON, Wis, -

A dead crow found in Dodge County is the first sign of West Nile Virus in Wisconsin this season. It’s the first bird to test positive this year.

State health officials say infected birds serve as an early warning that the virus is present and they encourage people to be more vigilant in protecting themselves against mosquito bites.

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

In 2013, 21 cases of West Nile virus infection were reported among Wisconsin residents. Most people reported getting West Nile virus during August and September.

The chances of a person becoming infected with West Nile virus are low and most infected people will not have any symptoms, according to state officials.

More information on West Nile virus is available here.