Fourth person dies in Michigan from mosquito-borne virus

Detroit News staff and wire reports

A fourth Michigan resident has died from rare mosquito-borne virus that has been recorded across the southern half of the state.

WWMT-TV reports that 79-year-old Stan Zalner of Battle Creek died Wednesday after contracting eastern equine encephalitis, or EEE.

A female Aedes albopictus mosquito acquiring a blood meal from a human host.

Ronna Bagent tells the television station that her father was hospitalized in September with severe flu-like symptoms before doctors were able to confirm the illness through blood tests.

As of Monday, nine cases had been confirmed in six southern or southwestern Michigan counties, according to the Michigan Department of Health and Human Services.  

Cases have also occurred in 33 animals from 15 counties: Allegan, Barry, Berrien, Calhoun, Cass, Genesee, Jackson, Kalamazoo, Kent, Lapeer, Livingston, Montcalm, Newaygo, St. Joseph and Van Buren, the department reported Wednesday.

Two Mexican gray wolf pups at a Battle Creek zoo died from the virus.

"The mosquitos that spread EEE are still active and were caught in traps set Oct. 1 in southwest Michigan," state health officials said in a statement Wednesday.

In a bid to prevent the condition from spreading, state officials have started aerial insecticide spraying for the first time since 1980. Officials said the pesticide, Merus 3.0, will not pose a health risk to humans or animals, including bees and other pollinators such as butterflies.

In announcing the move Friday, Michigan officials cited the large geographic distribution and number of cases along with warm weather projections. Mosquitoes generally do not die until the first hard frost. The pesticides kill adult mosquitoes on contact.

After a delay, the spraying started Monday. The coverage area has been expanded to include parts of Livingston and Washtenaw counties.

Some 186,146 acres across the state have been sprayed, according to the state health department. Inclement weather forced treatments scheduled for Wednesday to be postponed.

Southwest Michigan has experienced outbreaks of the disease in people and horses in the past, with the most recent outbreaks in the early 1980s, mid-1990s and 2010.

Three people were infected in Michigan in 2016, state officials reported. According to the CDC, the state reported seven cases between 2009 and 2018.

Eastern equine encephalitis is among the most dangerous mosquito-borne diseases in the United States. It has a 33% fatality rate in people who become ill and a 90% fatality rate in horses, state health officials said.

EEE is carried by certain types of mosquitoes found primarily in areas with swamps and bogs, according to the state.

The risk of bites from infected mosquitoes is highest for people who work or play outdoors in those areas. According to the Centers for Disease Control and Prevention, EEE is transmitted by mosquitoes that feed on infected bird hosts.

"Persons younger than age 15 and over age 50 are at greatest risk of severe disease following infection," the department said.

Signs of EEE include the sudden onset of fever, chills, and body and joint aches. The condition can develop into severe encephalitis, resulting in headache, disorientation, tremors, seizures and paralysis. Permanent brain damage, coma and death might occur. 

To protect against disease-spreading mosquitoes, health officials advise residents to:

  • Apply insect repellents with the active ingredient DEET, or other U.S. Environmental Protection Agency-approved product, to exposed skin or clothing
  • Wear long-sleeved shirts and long pants when outdoors
  • 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 may lay eggs
  • Use nets and/or fans over outdoor eating areas

For more information: