Michigan’s first mosquito-borne virus of 2024 detected

Risk for mosquito-borne illness peaks in August, September

DETROIT – Health officials are urging Michiganders to take precautions after authorities have confirmed the first infected mosquitoes of 2024.

Related: These 5 plants can help keep mosquitoes away

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According to the Michigan Department of Health and Human Services (MDHHS), mosquitoes collected in Saginaw County on May 22 have tested positive for Jamestown Canyon Virus (JCV).

JCV and other mosquito-borne viruses are transmitted through the bite of an infected mosquito. Most people who get the virus have no symptoms of illness, but some become ill two to 14 days after the bite.

Symptoms of JCV include high fever, confusion, muscle weakness, headache, and fatigue. In rare cases, JVC can cause severe disease in the brain and/or spinal cord including encephalitis and meningitis.

“It only takes one bite from an infected mosquito to cause a severe illness,” said Dr. Natasha Bagdasarian, MDHHS chief medical executive. “We urge Michiganders to take precautions such as using an EPA-registered insect repellent when outdoors, avoiding areas where mosquitos are present if possible and wearing clothing to cover arms and legs to prevent bites.”

JCV sickened six Michiganders in 2021, one in 2022 and four in 2023. There were also 21 cases of West Nile Virus in 2023.

The best way to protect yourself from JVC, WNV and Eastern Equine Encephalitis is to prevent mosquito bites.

More information can be found on Michigan’s Emerging Diseases webpage.

Preventing mosquito bites

Michigan officials suggest taking the following steps to prevent mosquito bites:

  • When used as directed, Environmental Protection Agency (EPA)-registered insect repellents with one of the active ingredients below are proven safe and effective, even for pregnant and breastfeeding women: DEET, Picaridin (known as KBR 3023 and icaridin outside the US), IR3535, Oil of lemon eucalyptus (OLE), Para-menthane-diol (PMD), and 2-undecanone.
  • 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.
  • You could also hire a mosquito control business. Mosquito control businesses are required to be licensed to apply pesticides in Michigan. A list of Michigan firms licensed to apply pesticides is available online.

Mosquitoes lay eggs in or near standing water

Mosquitoes need standing water to reproduce. That’s why you should empty, scrub or cover any items that hold water.

Standing water is often found in old tires, buckets, planters, toys, pools, birdbaths, flower pot saucers or trash containers.

Mosquitoes can complete their life cycle in about a week. The CDC recommends using an outdoor insect spray made to kill adult mosquitoes. Mosquitoes are often found in dark, humid areas.

Can’t remove standing water? Larvicides are an option

If you’re unable to remove the standing water where you live then you’ve got one other option: Larvicides.

Larvicides work by killing mosquito larvae and pupae before they grow into pesky adults. According to the CDC, if you use larvicides correctly, they do not harm people, pets or the environment.

Larvicides come in liquids, tablets, bits, pellets, granules and briquettes. You use them by applying them where mosquitoes lay eggs (that means anywhere that holds standing water). That can include buckets and rain barrels, fountains, gutters or downspouts, non-chlorinated swimming pools, pool covers that collect water, tires and tree holes.

Use larvicides to treat standing water that will not be used for drinking and cannot be covered, dumped or removed.


About the Authors

Dane Kelly is a digital producer who has been covering various Michigan news stories since 2017.

Kayla is a Web Producer for ClickOnDetroit. Before she joined the team in 2018 she worked at WILX in Lansing as a digital producer.

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