Wisconsin Reports First Human West Nile Virus Case of 2025

Health authorities in Wisconsin have confirmed the state's first human case of West Nile virus for the year 2025. The case was identified in Barron County, and health officials have also detected the presence of the virus in mosquitoes collected from Milwaukee and Lafayette counties. These findings serve as a reminder of the importance of taking preventive measures against mosquito bites, especially as the virus poses a greater risk to individuals with weakened immune systems.

West Nile virus is primarily transmitted through the bite of infected mosquitoes, which acquire the virus by feeding on birds carrying it. It is not spread through person-to-person contact or from animals directly to humans. Most individuals infected with West Nile virus remain asymptomatic, but some may experience flu-like symptoms including fever, headache, muscle aches, fatigue, chills, and rashes.

In rare but severe cases, especially among older adults and those with compromised immune systems, the illness can escalate to high fever, muscle weakness, stiff neck, confusion, tremors, seizures, paralysis, or even coma. Health officials recommend using insect repellents containing DEET, picaridin, oil of lemon eucalyptus, or IR3535 on skin and clothing, and treating clothing with permethrin to reduce risk.

Additional precautions include wearing long sleeves, pants, and socks outdoors, avoiding peak mosquito activity times at dawn and dusk, and eliminating standing water from property to prevent mosquito breeding. This includes emptying containers, turning over unused items, maintaining swimming pools, repairing window screens, and trimming overgrown vegetation.

Further information on West Nile virus, including symptoms and treatment options, can be found through the CDC. These measures are vital in protecting communities from the spread of the virus as the mosquito season continues.

Source: https://medicalxpress.com/news/2025-07-wisconsin-west-nile-virus-case.html