Skip to main content

Residents urged to protect against mosquito bites as first mosquito-borne virus of 2024 detected in Saginaw County

LANSING, Mich. – Michigan residents are being urged to take precautions against mosquito bites as mosquitos collected in Saginaw County on Wednesday, May 22, have tested positive for Jamestown Canyon virus (JCV) at the Michigan Department of Health and Human Services Bureau of Laboratories (MDHHS BOL). These are the first infected mosquitos detected for 2024.

Residents are reminded that the best way to protect themselves against JCV and other mosquito-borne illnesses, including Eastern Equine Encephalitis (EEE) and West Nile virus (WNV), is to prevent mosquito bites.

“It only takes one bite from an infected mosquito to cause a severe illness,” said Dr. Natasha Bagdasarian, 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.”

Every summer in Michigan, bites from mosquitos carry the risk of spreading diseases to people and animals. This year’s warm, wet spring has produced a variety of biting mosquitoes. The majority are mosquitos that hatched in early May and are currently active in tracts of woodland habitat. Some of these spring mosquitos are capable of transmitting JCV. JCV sickened six Michiganders in 2021, one in 2022 and four in 2023. Also reported last year were 21 cases of WNV.

JCV is spread to people through bites from infected mosquitos. Most cases occur from late spring through mid-fall. Illness can develop within a few days to two weeks following a bite from an infected mosquito. While most people do not become ill, initial symptoms can include fever, headache and fatigue. In rare cases, it can cause severe disease in the brain and/or spinal cord including encephalitis and meningitis.

While the JCV is found throughout much of the United States, cases have been increasing in the Midwest. This likely reflects increased awareness and testing but may also be due to an increase in the presence of the virus in the environment. This is the fourth year that the MDHHS BOL is offering virus testing of mosquitos collected by local health departments and county mosquito control programs. Testing is offered to improve detection and notification of mosquito-borne viruses.

JCV can be spread by mosquitos that become infected when they feed on deer or other animals that have the virus in their blood. Infected mosquitos spread the virus to other animals or people through bites. Arboviruses, including WNV and EEE, spread when mosquitos contract the virus from biting infected birds then biting a human.

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

  • Apply insect repellents that contain the active ingredient DEET or other EPA-approved products to exposed skin or clothing. 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 mosquitos outside.
  • Empty water from mosquito breeding sites around the home, such as buckets, unused kiddie pools, old tires and other water-holding containers where mosquitos can lay eggs.

For more information, visit

# # #





Media Contact: