Wisconsin state health officials have reported the  year’s first confirmed human cases of West Nile virus (WNV) in residents of Oconto and Fond du Lac Counties.

Wisconsin map/National Atlas of the United States
Wisconsin map/National Atlas of the United States

The majority of WNV human cases in the state occur during the months of August and September. However, the risk of contracting WNV and other mosquito-borne illnesses is present anytime mosquitoes are active, so it is important for people to be vigilant in their personal protective measures to prevent mosquito bites throughout the summer and early fall.

The chances of a person contracting WNV are very low and most people infected with West Nile virus will not have any symptoms. Those who do become ill may develop a fever, headache, and rash that lasts a few days. Symptoms may begin between three to 15 days after being bitten by an infected mosquito. In rare cases, WNV can cause severe disease with symptoms such as muscle weakness, stiff neck, disorientation, tremors, convulsions, paralysis and coma. Older adults and people with compromised immune systems are at an increased risk of severe disease from the virus.

There is no specific treatment for West Nile virus other than to treat symptoms. If you think you have West Nile virus infection, contact your healthcare provider.

WNV is spread to people through the bite of an infected mosquito and is not transmitted person to person.

During 2016, 13 cases of West Nile virus infection were reported among Wisconsin residents.