The Oakland County Health Division identified the county's first probable human West Nile Virus case of 2026 on Thursday, Sept. 10, urging residents to guard against mosquito bites through the fall.
The health division released no details about the patient, citing health privacy laws, The Detroit News reported. The advisory covers all Oakland County residents, including those in Rochester, Rochester Hills and Oakland Township.
Seven human cases of mosquito-borne disease have been confirmed statewide in 2026: six West Nile Virus and one Eastern Equine Encephalitis. Michigan's first West Nile case this year was found Aug. 13 in a Kent County resident through routine blood-donation screening. Wayne County reported its first case Aug. 26.
"We strongly encourage residents to protect themselves from mosquitoes until the first hard frost of the year," Kate Guzman, health officer for Oakland County Health Division, said in the announcement.
The virus can be fatal. People over 50 face a higher risk of serious, potentially life-threatening symptoms if infected, according to the health division. Most people who contract West Nile experience no symptoms or mild illness such as fever, headache and body aches. In some cases, the virus can cause inflammation and swelling of the brain.
West Nile spreads when a mosquito bites an infected bird and then bites a human. Transmission in Michigan peaks between late August and early September, according to the Wayne County Health Division, and the risk persists until a hard frost kills adult mosquito populations.
Michigan recorded 17 human West Nile cases statewide during the 2025 season, according to the Wayne County Health Division.
How to protect yourself
The Oakland County Health Division recommends these steps:
- Use EPA-registered insect repellent containing DEET, picaridin, IR3535, oil of lemon eucalyptus or para-menthane-diol. Products with oil of lemon eucalyptus or para-menthane-diol should not be used on children under 3.
- Eliminate standing water around your home weekly. Empty tires, buckets, planters, birdbaths, pet bowls and flowerpots. Clean clogged roof gutters. Standing water can also be treated with mosquito larvicide, available at most home improvement stores.
- Wear long sleeves and pants, especially from dusk to dawn when mosquitoes are most active. Check window and door screens for holes.
Residents can find more information at OakGov.com/Health or by calling the Oakland Connects Helpline at 800-848-5533, Monday through Friday, 8:30 a.m. to 5 p.m.
