Human Cases of West Nile Virus Reported in Milwaukee

MILWAUKEE – The City of Milwaukee Health Department is advising residents to take steps to prevent mosquito bites following the report of two human cases of West Nile virus (WNV) in Milwaukee. Several other cases have been reported in Wisconsin this year. In addition, WNV has been detected in animals, mosquitoes, and screened blood donors.

WNV is transmitted to humans and animals through the bite of an infected mosquito, which becomes infected after feeding on birds carrying the virus. The virus cannot be spread directly between people, animals, or from animals to humans.

WNV cases in Wisconsin are most common during August and September, but the risk continues as long as mosquitoes are active, typically until the first hard frost. Other mosquito-borne illnesses, such as Jamestown Canyon virus, La Crosse encephalitis virus, or eastern equine encephalitis virus, also pose a threat during this period.

Most people infected with WNV (around 80%) do not develop symptoms. Those who do may experience mild symptoms like fever, headache, muscle aches, rash, and fatigue. In rare cases (less than 1%), the virus can lead to severe illness, with symptoms such as high fever, muscle weakness, stiff neck, disorientation, tremors, paralysis, and coma. Older adults and individuals with weakened immune systems are at greater risk of serious complications. Anyone experiencing symptoms of WNV should contact a healthcare provider immediately.

Wisconsin public health officials have monitored WNV since 2001, with an average of 18 cases reported annually. To reduce the risk of WNV and other mosquito-borne illnesses, residents are encouraged to minimize exposure to mosquitoes and eliminate breeding sites. The threat of WNV continues until a hard frost, defined as temperatures below 28°F for at least four consecutive hours. Local health departments recommend the following prevention tips:

Avoid Mosquito Bites

• Use insect repellents containing DEET, picaridin, oil of lemon eucalyptus, or IR3535.
• Treat clothing with permethrin before going outdoors; do not apply permethrin directly to the skin.
• Reschedule outdoor activities during peak mosquito activity in the evening and early morning.
• Wear long sleeves, pants, and socks to cover exposed skin.

Mosquito-Proof Your Home

• Remove standing water to prevent mosquito breeding:
  • Empty water from containers, flower pots, tires, gutters, and downspouts.
  • Turn over items like wheelbarrows, kiddie pools, buckets, and boats when not in use.
  • Change water in birdbaths and pet dishes every three days.
  • Clean and chlorinate pools, hot tubs, and saunas, and drain pool covers.
• Ensure window and door screens are intact to keep mosquitoes out.
• Trim tall grass, weeds, and vines where mosquitoes rest during the day.

NOTE: This press release was submitted to Urban Milwaukee and was not written by an Urban Milwaukee writer. While it is believed to be reliable, Urban Milwaukee does not guarantee its accuracy or completeness.