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The Land of 10,000 Mosquitoes Fights Back
By Brent Wolfe
May 28, 1999
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Mosquito experts are expecting a bumper crop after all the recent wet weather. That's troubling for health officials in the Twin Cities and southeastern Minnesota - areas of the state with mosquitos that carry encephalitis. Nearly a quarter of the state's encephalitis cases since 1985 were recorded in sparcely populated Houston County in the far southeast corner of the state. Houston County officials are using a new technique to reduce the number of encephalitis cases.

LAST SUMMER, SORIN LEHMAN THOUGHT her daughter Morgan had a bad case of the flu. Then one day, eight-year-old Morgan was eating a peanut butter sandwich when she went into a siezure. "She could not hear," her mother recalls. "She did not respond. She also had seemingly no control of her limbs. Her arms would just raise for no apparent reason and almost like float above her and I'd bring her hand down and it would just once again go up again."

Lehman rushed to the hosptial in La Crosse and 10 minutes after they arrived, Morgan stopped breathing. She had encephalitis, or swelling of the brain. She was on a respirator for five hours and in the hospital for five days before her body fought off the infection. Morgan got the virus that caused the infection from a tree-hole mosquito.

Usually, doctors say, adults can fight off the virus but in Minnesota four or five children become sick from it each year. Houston County Public Health Director Linda Sorensen says the symptoms can be long-lasting. "You don't want to see your children starting off with neurological deficits whether speech problems, developmental delays, gate and coordination problems,"Sorenson says. "If you think about the parts of your brain that are damaged by the swelling it would be similar to what a stroke patient would go through with the swelling in the brain from the bleeding in the brain."

There is no cure for encephalitis. Sorensen says the best way to fight it is to reduce the population of tree-hole mosquitoes. Dave Geske chases these mosquitoes for a living with the La Crosse County Health Department. He says tree-hole mosquitoes were not prolific breeders until humans gave them an edge.

"Tree holes just aren't a very efficient habitat," says Geske. "The natural habitat is not very efficient. So in nature, we don't find these in real large numbers these. But what's happened is man has come along and provided better habitat particularly with unrimmed tires. Well find it breeding in tin cans and buckets and a number of containers that are left outside but unrimmed tires are an ideal incubator for this species."

While scientists did once find some tree hole mosquitoes breeding in the ear of a G.I. Joe doll left outside in a cool spot, Geske says tires have provided the habitat for 80 percent of the recorded cases of encephalitis. So Houston County officials secured a nearly $25,000 grant from the Minnesota Pollution Control Agency to clean up old tires dumped in ditches or abandoned on people's property.

Houston County Solid Waste Administrator Rick Frank is supervises a sentence-to-serve crew loading a pile of dirty, worn, and cracked tires into the back of a semi-trailer. The county used the MPCA grant to purchase equipment that allowed them to lift tires out of remote ravines. In one spot, they found almost 400 tires. County residents can bring up to four tires at a time to the recycling center for free. Frank says the fee for additional tires will be waived through June.

Twenty-three people are on a waiting list who have large numbers of tires to discard. Rick Frank hopes to ship off 10,000 to 15,000 tires in the next four weeks. The county also sends out surveillance teams looking for abandoned tires and after the tire amnesty ends in June, the county will send out crews to pick them up and send the property owner a bill.