First West Nile virus cases of 2021 detected in Metro Detroit

Virus is not contagious, spread by mosquitoes

PLEASANT HILL, CA - JUNE 29:  Mosquitos are seen inside a trap on June 29, 2012 in Pleasant Hill, California. As reports of mosquitoes with West Nile virus are increasing across the country and several people have been confirmed to be infected by the potentially dangerous disease, the Contra Costa County Mosquito and Vector Control District is testing mosquito larvae found in standing water throughout the county and is using mosquito fish and BVA Larvacide oils to eradicate the pest.  (Photo by Justin Sullivan/Getty Images)
PLEASANT HILL, CA - JUNE 29: Mosquitos are seen inside a trap on June 29, 2012 in Pleasant Hill, California. As reports of mosquitoes with West Nile virus are increasing across the country and several people have been confirmed to be infected by the potentially dangerous disease, the Contra Costa County Mosquito and Vector Control District is testing mosquito larvae found in standing water throughout the county and is using mosquito fish and BVA Larvacide oils to eradicate the pest. (Photo by Justin Sullivan/Getty Images) (2012 Getty Images)

The first West Nile virus cases of the year have been confirmed in Oakland and Macomb county residents.

MDHHS said the cases were detected after multiple samples of mosquitoes collected in the City of Detroit and Bay, Kent, Macomb, Midland, Oakland and Wayne counties have tested positive for West Nile virus (WNV) and Jamestown Canyon virus (JCV).

Additionally, EEE virus was identified in a sick deer from Livingston County. 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. About 1 in 5 people who are infected develop a fever and other symptoms. About 1 out of 150 infected people develop a serious, sometimes fatal, illness.

WNV does NOT spread from person-to-person contact, according to the CDC. It’s not contagious. Humans are a dead-end host for the virus.

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.

Related: Michigan mosquitoes getting worse? Here’s how to find, fight them

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.

Related: Let’s talk about Michigan mosquitoes: Are they eating you alive? Here’s what to know

West Nile virus transmission cycle. (WDIV)

About the Author:

Ken Haddad is the digital special projects manager for WDIV / ClickOnDetroit.com. He also authors the Morning Report Newsletter and various other newsletters. He's been with WDIV since 2013.