Michigan confirms first human mosquito-borne virus of 2020

Ottawa County resident infected with Jamestown Canyon virus 

July 14, 2020
Contact: Bob Wheaton, 517-241-2112

LANSING, Mich. – The Michigan Department of Health and Human Services (MDHHS) and Ottawa County Health Department today confirmed the state’s first human infection with a mosquito-borne virus for 2020 as a county resident tested positive for Jamestown Canyon virus.

Jamestown Canyon virus is spread to people through bites from infected mosquitoes.  Most cases occur from late spring through mid-fall. Illness can develop from a few days to two weeks following a mosquito bite. While most people do not become ill, initial symptoms can include fever, headache and fatigue. In rare cases, it can cause severe disease, including infection of the brain – encephalitis – or the lining around the brain and spinal cord – meningitis.

MDHHS is releasing no further information about the resident who tested positive for confidentiality reasons.

“During the warm weather months in Michigan, there is always a risk of viruses spread by mosquitoes, including but not limited to West Nile virus and Eastern Equine Encephalitis.” said Dr. Joneigh Khaldun, MDHHS chief medical executive and chief deputy director for health. “This is an important reminder to stay vigilant and protect against mosquito bites throughout the summer and into the fall”.

Michigan reported its first two cases of Jamestown Canyon virus in 2018 in patients from Oakland and Menominee counties. In 2019, one case was detected in a person from Cass County.

While the virus is found throughout much of the U.S., reports have been increasing in the upper 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.

The virus can be spread by many types of mosquitoes that become infected when they feed on deer or other animals that have the virus in their blood. These infected mosquitoes can then spread the virus to other animals or people through bites.

Residents can stay healthy by using simple, effective strategies to protect themselves and their families. The following steps are recommended to avoid Jamestown Canyon virus and other 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 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.

For more information and surveillance activity about West Nile virus and other mosquito-borne viruses, visit www.michigan.gov/westnilevirus.

# # #