How to prevent Lyme disease
The bite of a deer tick can cause major headaches, and more.
© Beth Gauper
In late April, a hiker picked up a deer tick near Cable, Wis.
In the woods, the first ticks appear along with warmer weather, usually by late April.
Regular ticks are bad enough, scuttling into hidden niches on the human body and gorging themselves on blood. But their ick factor pales next to the danger posed by black-legged ticks, which can transmit Lyme disease.
Black-legged ticks, also known as deer ticks, need to be attached to the skin for 24 to 36 hours to transmit the disease. Even then, it’s easily treatable if caught promptly.
But if untreated, symptoms include fatigue, fever and achiness; eventually, it can lead to nerve damage and chronic joint pain.
Minnesota has nearly overtaken Wisconsin as the epicenter of Lyme disease
in the Upper Midwest, with 1,174 confirmed and 631 probable cases in 2015, according to
the Centers for Disease Control and Prevention.
In Wisconsin, there were 1,309 confirmed cases and 585 probable cases in 2015. Cases in both states rose.
Field studies in Minnesota have shown that about one-third of adult ticks and one in five young ticks, called nymphs, carry the bacteria that causes Lyme disease.
A Scientific American map shows where humans are at most risk of Lyme disease. The incidence of the disease is even higher in New England, with 107 cases per 100,000 people in Vermont, as opposed to 26 cases per 100,000 in Minnesota.
Here are the best ways to prevent infection.
Tuck in shirts and pants. To make ticks easier to see, wear light-colored clothing. Nymphs may look like a moving freckle.
Spray skin and clothing with bug spray containing 30 percent DEET, or spray clothing with Permethrin clothing repellent. An aerosol can that will spray three sets of clothing costs about $10. They're available at outdoors stores.
Run hands over skin
to detect the smaller ticks, then again in the shower.
If you find one, grasp its head gently, with
tweezers or your fingers, and pull it out slowly. Then, disinfect the bite site.
Ticks also can hide in the folds of clothing or boots and crawl onto the body later. Putting clothing in a dryer on high heat for at least 10 minutes will kill them.
And here's an ingenious idea: Wrap a strip of duct tape, sticky side out, around your cuffs
to keep ticks
from crawling up your legs and arms.
If you want to be especially safe,
wrap it around your collar, too, to keep them out of your hair — although ticks don't drop out of trees; they get to your head by crawling.
If you spend a lot of time in tick country, and you think you still might get bitten, some doctors recommend you get an advance prescription for a one-time, 200 milligram dose of the antibiotic doxycycline. You still need to go to the doctor, but at least you can get a head start on treatment.
Depending on location, says Dr. Russell Johnson, a microbiologist who studies agents of Lyme disease at the University of Minnesota, 40 to 60 percent of adult
female black-legged ticks carry Lyme disease.
Inside the fish hook: a female deer tick, left, with a male (below her) and two nymphs. On the right, a common dog tick.
The first ticks out mostly are adults; the nymphs that appear from mid-May to early July carry the disease at about half that rate, but all are looking for blood meals and are harder to see.
Deer-tick nymphs appear as black dots, the size of a poppy seed; adults are the size of a sesame seed.
About 80 percent of people will develop an even red rash that may look like a bull’s-eye rash, Johnson said.
But even if you don’t, and you develop an unexplained fever or ache about two weeks after spending time in woods, consider the possibility of Lyme disease.
Robert Sitko of Stillwater, Minn., a beekeeper who tends apiaries in the heavily infested St. Croix River Valley and likes to go camping, knew he was at risk. One year, he saw the tell-tale bull’s-eye rash of Lyme disease on his body and went to a doctor, who prescribed three weeks of antibiotics.
That was that — until a year later, when he ran a 105-degree fever and landed in the hospital. That time, it was anaplasmosis, also known as ehrlichiosis, another bacterium transmitted by deer ticks.
Now, Sitko does everything he can to avoid being bitten by a deer tick. He tucks his pants legs into his socks. He checks skin and clothes religiously. He uses insect repellents.
He might have taken the vaccine if it hadn’t been discontinued for human use, but he gets a shot of it for his German shorthair dog every year.
And after he found a deer tick while cutting trees in his back yard, he drove to a sporting-goods store and bought a canister of Permethrin clothing repellent.
“What you do is spray it on your clothes, let it dry two hours, and it’s supposed to last six weeks or six washings,’’ he said. “Supposedly, it kills ticks on contact. I thought, that’s the perfect thing for people going on a week’s camping trip.’’
Microbiologist Johnson confirms that the product does work.
“It works very well,’’ he says. “In fact, it kills ticks within seconds of contact.’’
Western Wisconsin and the St. Croix Valley of Minnesota are considered hot spots for Lyme-carrying deer ticks, but they’ve expanded their range northward and westward to northern Minnesota, Johnson said.
In Iowa, 130 cases were confirmed in 2015, and in Illinois, 287 cases. In Michigan, 125 cases were confirmed in 2015. Cases rose in all three states.
The Minnesota DNR has a page about deer ticks.
The Centers for Disease Control lists signs and symptoms of Lyme disease.
Read a fascinating story about "The Rise of the Tick'' in Outside magazine, which quotes the Institute of Medicine declaring ticks “the Swiss Army knife of disease vectors.”
The story also includes guidelines for keeping ticks away, with a photo of the tell-tale bull's-eye rash.
Business Insider calls it a "hidden epidemic'' that has "ballooned into a public-health fiasco."
In 2016, the New York Times reported that a new strain of tick-borne bacteria had been found in the Upper Midwest.
Last updated on May 7, 2018