Skip to main content

First human case of West Nile virus for 2020 confirmed in Michigan Cases of Eastern Equine encephalitis virus in horses are on the rise

September 3, 2020
MDHHS CONTACT: Lynn Sutfin, 517-241-2112
MDARD CONTACT: Jessy Sielski, 517-331-1151

LANSING, Mich. – The Michigan Department of Health and Human Services (MDHHS) today confirmed the first human case of West Nile virus (WNV) for 2020 in a Wayne County resident.

“As we approach a long holiday weekend, it’s vital to continue protecting your family from mosquito bites,” said Dr. Joneigh Khaldun, chief medical executive and chief deputy for health at MDHHS. “It only takes one bite from an infected mosquito to cause a severe illness, so take extra care during peak mosquito-biting hours, which are dusk and dawn for the mosquitoes that transmit West Nile virus and Eastern Equine encephalitis virus.”

In addition to WNV, Eastern Equine encephalitis (EEE) virus is again circulating in Michigan, with 13 confirmed cases in horses from Barry, Clare, Kent, Montcalm, Newaygo and Oakland counties.

“Whether you’re talking about West Nile, EEE or any other mosquito-borne disease, people and animal owners should take every precaution necessary to prevent infection,” said State Veterinarian Nora Wineland, DVM. “There is a lot happening in people’s lives right now, but we can’t let our guard down. I strongly urge animal owners to work with their veterinarian to make sure all their animals are vaccinated appropriately.”

To date, two birds have tested positive for WNV from Lapeer and Oakland counties. In addition, 14 WNV positive mosquito pools have been detected in five Michigan counties, including Arenac, Kent, Lapeer, Oakland and Saginaw. Finding infected birds, animals and mosquitoes in a community is an indication of risk for human infection.

In 2019, the WNV season was less severe, with only 12 human cases, including two deaths, reported. However, the state experienced the worst outbreak of EEE virus ever recorded, with 10 human cases, including six deaths and 50 cases in animals. Between Sept. 28 and Oct. 10, 2019, more than 557,000 acres in Michigan were treated with aerial applications of insecticide to kill infected mosquitoes and prevent additional cases. 

Most people who become infected with WNV will not develop any symptoms of illness. However, some become sick three to 15 days after exposure. About one in five infected persons will have mild illness with fever, and about one in 150 infected people will become severely ill.

Mild illness may include headache, body aches, joint pain, vomiting diarrhea or rash. Severe symptoms of WNV are associated with encephalitis or meningitis, and may include stiff neck, stupor, disorientation, coma, tremors, muscle weakness, convulsions and paralysi

  • Apply insect repellents that contain the active ingredient DEET, or other EPA-approved product to exposed skin or clothing, and always follow the manufacturer’s directions for use. Wear light-colored, long-sleeved shirts and long pants when outdoors. Apply insect repellent to clothing to help prevent bites.
  • Maintain window and door screening to help keep mosquitoes outside.
  • Empty water from mosquito breeding sites around the home, such as buckets, unused kiddie pools, old tires or similar sites where mosquitoes lay eggs.
  • Use nets and/or fans over outdoor eating areas.

For more information and surveillance activity about West Nile virus and other mosquito-borne viruses, visit People 60 and older are more susceptible to these severe symptoms.

Residents can stay healthy by using simple, effective strategies to protect themselves and their families. The following steps are recommended to avoid WNV, EEE and other mosquito-borne diseases:

# # #