Sections of Berrien, Van Buren and Cass are among the locations where the Michigan health department will spray Sunday evening for mosquitoes that carry the rare but potentially fatal Eastern equine encephalitis.
With nine human cases and three deaths, this is the largest outbreak of EEE since the illness was first found here in 1980, according to Dr. Joneigh Khaldun, with the Michigan Department of Health and Human Services, who participated Friday in a conference call to answer questions about the spraying. In all, parts of 14 counties will be treated.
A second case has been confirmed in Berrien County, reported Gillian Conrad, communications director for the county health department. Deaths from the mosquito-borne illness occurred in Van Buren and Cass counties, as well as Kalamazoo County.
The number of human cases this year is larger than the total for the last 10 years, added Dr. Mary Grace Stobierski, State Public Health Veterinarian. Other states, including Massachusetts and Rhode Island, are experiencing outbreaks, as well.
The spraying was ordered as a way to reduce the mosquito population before the first hard frost that will kill off the insects, officials explained. This is the first time that widespread spraying to combat EEE has taken place since 1980. It is estimated to cost between $1.5 million and $1.8 million.
The aerial spraying is scheduled to start around 8 p.m. Sunday, weather permitting, and continue until 4:30 a.m.
In Berrien County, the spraying will take place in portions of Pipestone Township, Berrien Township, and the village of Eau Claire. In Van Buren County, areas targeted include a section along the Allegan County border, as well as central and east-central and southwest parts of the county. Sections in central and northeast Cass County will be sprayed.
The pesticides will be applied as an ultra-low volume spray as aerosol droplets that stay suspended in the air and kill adult mosquitoes on contact. The concentration will be one ounce per acre, equivalent to two tablespoons over a football field, experts said.
The pesticide being used is Merus 3.0 which is an organic pesticide containing 5 percent pyrethrin, chemicals found naturally in some chrysanthemum flowers. There are no health risks expected, but those who are sensitive to pyrethrin can stay indoors at the time of the spraying to reduce exposure. There is no anticipated risk to ground water or drinking water.
The spraying is being done at night when other insects, such as honeybees, will be in their hives and not exposed to the pesticide.
Dr. Rick Johansen, medical director of the Berrien County Health Department (BCHD), noted that EEE is an extremely rare, but dangerous, disease. About 30 percent of cases result in death. A small percentage of those bitten by a mosquito carrying EEE will become ill, and a smaller percentage will have serious effects, including brain swelling that can cause permanent disabilities.
Berrien’s two cases involved people who were exposed six weeks ago, Johansen said, and the county’s animal cases occurred even before that. After the latest confirmation of a case in Berrien, no other suspected cases are pending.
But with the risk of transmission still there, state officials decided to take the step of spraying, said Nicki Britten, health officer at the BCHD.
Berrien officials have had “robust conversations” with Michigan departments after being informed of the pending spraying on Sunday, Conrad said.
County officials reminded state workers about the requirement for public notice, Johansen said. They also were able to convince them to use a more agriculturally friendly spray, he added.
“We’re happy with the insecticide they ultimately decided to use,” he said.
Along with monitoring the disease, the health department has been busy educating residents about what they can do to reduce their exposure, Conrad said.
The state health department recommended that schools reschedule outdoor events that take place around dusk, stating the “MDHHS recommendation is being made out of an abundance of caution to protect the public health and applies until the first hard frost of the year.”
The Berrien health department did not take that step after considering the low risk, Britten said. They did suggest avoiding activities around swampy areas where mosquitoes breed.
U.S. Rep. Fred Upton, R-St. Joseph, has enlisted himself in the fight against Eastern equine encephalitis.
Following reports that three Michigan residents have died from the mosquito-borne virus, Upton sent a letter to the Center for Disease Control and Prevention requesting a congressional briefing to learn more about the CDC’s efforts to prevent the spread of the disease.
“Given the record numbers of EEE cases in Michigan and other at-risk states, we would appreciate the opportunity to learn more about the CDC’s efforts to prevent the spread of this vector-borne illness. I would also like to learn of any effort to develop treatments for those who have already contracted this disease,” Upton wrote.
Six counties in Upton’s Sixth District have been affected.
Information from the Berrien County Health Department, including a map of areas to be sprayed, is at www.berriencounty.org/CivicAlerts.
Contact: jmatuszak@TheHP.com, 932-0360, Twitter: @HPMatuszak