Officials Warn of Mosquito Bite Risks After Oakland County Resident Tests Positive for West Nile Virus

(MDHHS, Aug. 17, 2022)

West Nile virus (WNV) has been detected in a blood donation from a resident of Oakland County. The donor has experienced no symptoms of illness. Michigan residents are reminded that the best way to protect against WNV and other mosquito-borne illnesses such Eastern Equine Encephalitis virus (EEE) is to prevent mosquito bites.

Routine screening for WNV in blood donations helps ensure the safety of the blood supply in Michigan and in the U.S. Donations that test positive for WNV do not enter the blood supply. In 2021, WNV was detected in seven Michigan blood donors.

“We want to remind residents of Michigan that mosquito season is not over and it only takes one bite from an infected mosquito to cause a severe illness,” said Dr. Natasha Bagdasarian, MDHHS chief medical executive. “Take precautions such as using insect repellent and wearing long-sleeve shirts and long pants when outdoors during times when mosquitoes are active.”

To date, WNV has been found in mosquitoes collected in Iosco, Arenac, Huron, Genesee and Kent counties, as well as birds collected in Bay and Shiawassee counties.  No other human cases have been reported to date. Mosquito pools from Bay, Midland and Saginaw have tested positive for Jamestown Canyon virus. The risk for mosquito-borne illness rises throughout the state over the course of the mosquito season – peaking in August and September.

WNV is transmitted through the bite of a mosquito that has picked up the virus by feeding on an infected bird. Most people who contract the virus have no clinical symptoms of illness, but some may become ill three to 15 days after the bite of an infected mosquito. Symptoms of arbovirus infection, like WNV, typically include a high fever, confusion, muscle weakness and a severe headache. More serious complications include neurological illnesses, such as meningitis and encephalitis.

The best way to prevent West Nile disease or any other mosquito-borne illness is to reduce the number of mosquitoes around your home and to take personal precautions to avoid mosquito bites.

Precautions include:

  • Using EPA registered insect repellents with one of the following active ingredients: DEET, picaridin, IR3535, oil of lemon eucalyptus or para-menthane-diol, and 2-undecanone; follow the product label instructions and reapply as directed.
  • Don’t use repellent on children under 2 months old. Instead, dress your child in clothing that covers arms and legs and cover crib, stroller and baby carrier with mosquito netting.
  • Wearing shoes and socks, light-colored long pants and long-sleeved shirts when outdoors.
  • Making sure doors and windows have tight-fitting screens. Repair or replace screens that have tears or other openings.
  • Using bed nets when sleeping outdoors or in conditions with no window screens.
  • Eliminating all sources of standing water that can support mosquito breeding around your home, including water in bird baths, abandoned swimming pools, wading pools, old tires and any other object holding water once a week.

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