First Mosquito Pool Tests Positive for West Nile Virus in the City of Milwaukee
Health officials remind residents to continue to take precautions into summer season
MILWAUKEE – The University of Wisconsin – Medical Entomology Lab has confirmed that a mosquito pool in the City of Milwaukee has tested positive for the West Nile Virus (WNV). This positive pool represents the first evidence of WNV activity reported in Wisconsin this year. A mosquito pool is merely a collection of a mosquito species or group that are likely to carry or transmit a virus. There is currently no confirmed case of an infected human. The Wisconsin Department of Health Services (DHS) and the City of Milwaukee Health Department (MHD) are advising residents to continue to protect themselves against mosquito bites.
“These positive mosquitoes are a reminder that West Nile virus may be present in areas around the state,” said State Health Officer Jeanne Ayers. “We urge everyone in Wisconsin to take precautions to prevent mosquito bites and the illnesses they spread.”
“Now that summer is officially here, it is important that residents remain vigilant about preventing mosquito bites,” said Commissioner of Health, Dr. Jeanette Kowalik. “The possibility of exposure to West Nile Virus is present anytime mosquitos are active.”
Approximately 80% of people infected with WNV do not experience symptoms. The remaining 20% may experience fever, rash, headache fatigue, and joint pain. Symptom onset is typically 3 to 14 days after being bitten by an infected mosquito. In rare cases, WNV can cause severe disease leading to possible muscle weakness, stiff neck, disorientation, tremors, convulsions, paralysis and coma. Older adults and people with compromised immune systems are at an increased risk of experiencing more severe symptoms. There is no specific treatment for WNV. Symptomatic supportive care is provided when appropriate.
WNV is spread to people through the bite of an infected mosquito and is not transmitted person to person. DHS and the MHD remind individuals to take steps to prevent mosquito bites, including:
- Apply an insect repellant with DEET, IR 3535, Picaridin, or oil of lemon eucalyptus to clothing as well as exposed skin (see restrictions for use in children).
- All these products can be found in your local drug or outdoor stores. For more information on repellent use, visit the CDC’s website: https://www.cdc.gov/westnile/faq/repellent.html
- Wear long-sleeved shirts and pants to cover exposed skin.
- Limit time outdoors at dusk and dawn, when mosquitos are most active.
- Prevent mosquitos from breeding by removing stagnant water from areas such as flowerpots, plastic containers, gutters and downspouts. Water in birdbaths and pet dishes should be changed at least every three days. Swimming pools, outdoor saunas and hot tubs should be cleaned and chlorinated.
- Trim tall grass, weeds, and vines as mosquitoes use these areas to rest during hot daylight hours, and landscaping to prevent water from pooling in low-lying areas.
- Report sick or dead birds to the Dead Bird Hotline at 1-800-433-1610; the line is open each year from May 1st – October 31st.
- Mosquito-proofing your home by fixing holes in screens, windows, and doors.
For more information on West Nile Virus, visit:
Department of Health Services: https://www.dhs.wisconsin.gov/mosquito/wnv-data.htm
City of Milwaukee Health Department: www.milwaukee.gov/westnilevirus