A lab assistant drops mosquitoes into test tubes as she prepares them to be tested for various arboviruses at the Northwest Mosquito Abatement District headquarters in Wheeling, Illinois. The Michigan Department of Health and Human Services Bureau of Laboratories recently identified seven pools of mosquitos infected with the Jamestown Canyon virus. (Photo by Tim Boyle/Getty Images)
OSCEOLA COUNTY — The wet weather pattern settled over the area has health officials warning Michiganders to prepare for the mosquitos that will follow.
“The mild winter weather and the recent rainfall have made ideal conditions for an explosion in the mosquito population,” officials at Central Michigan District Health Department said in a news release.
Beyond the annoying itch these bloodsuckers inflict on their victims, it’s the transmission of diseases — Eastern Equine Encephalitis (EEE) and West Nile virus — that concern health officials.
In 2020, 39 Michiganders contracted a mosquito-borne illness: 31 with West Nile virus; four with EEE, resulting in two deaths; and three with Jamestown Canyon virus according to the Michigan Department of Natural Resources. None of the human cases were in Mecosta, Osceola or Lake counties, however, Mecosta County reported one case of EEE in an animal.
As of Thursday, July 15, only the Jamestown Canyon virus had been identified in 2021, according to the latest 2021 Michigan Arbovirus Surveillance weekly summary. Positive mosquitos were found in Bay, Oakland and Saginaw counties.
WHAT TO LOOK FOR
West Nile: While most people with West Nile will not have symptoms, about one in five will develop a fever. Headaches, body aches, joint pains, vomiting, diarrhea or rash also are common. Fatigue and weakness may last for weeks or months.
Less than 1% will develop serious neurologic illness, such as encephalitis or meningitis. In addition to headache and high fever, symptoms may include neck stiffness, disorientation, coma, tremors, seizures or paralysis. Mortality rate is about 10%
People age 60 and older have the greatest risk for severe illness, along with people who have certain medical conditions. For more information, visit michigan.gov/westnilevirus.
Eastern Equine Encephalitis: Like West Nile, most people who contract EEE will develop symptoms. About 5% will develop chills, fever, weakness, muscle and joint pain for up to two weeks. Fatigue and weakness may last for weeks or months.
For the less than 1% who develop severe neurologic illness, symptoms may include high fever, headache, irritability, restlessness, drowsiness, anorexia, vomiting, diarrhea, bluish discoloration of the skin, convulsions, and coma. Mortality rate is 30%.
High risk populations include older adults and those with certain medical conditions, as well as children. For more information, visit michigan.gov/eee.
Jamestown Canyon: This is the first year the Michigan Department of Health and Human Services have tested for Jamestown Canyon virus. According to a news release, cases have been increasing in the Midwest.
Like EEE and West Nile, most people infected with Jamestown Canyon virus do not experience symptoms. Those who do may experience fever, headache and fatigue. In rare cases, it can cause severe neurologic illness, such as encephalitis or meningitis.
HOW TO PROTECT YOURSELF
Arboviruses, such as the three mentioned above, are transmitted by mosquitoes or other insects. Health officials encourage Michiganders to take steps to prevent being bitten.
“It only takes one bite from an infected mosquito to cause a severe illness,” Dr. Joneigh Khaldun, chief medical executive and chief deputy director for health at MDHHS, said in a news release reporting the Jamestown Canyon virus cases.
“We urge Michiganders to take precautions, such as using an EPA-registered insect repellent when outdoors, avoiding areas where mosquitoes are present if possible, and wearing clothing to cover arms and legs to prevent bites.”
Other tips include:
• Fixing and maintaining screening on doors and windows; and
• Emptying standing water, such as in buckets, pools or old tires, to reduce areas mosquitoes can lay eggs.
For more information, visit michigan.gov/emergingdiseases.
