This isn't a problem that's coming. It's already here or almost here, really here, as in here in southeastern Wisconsin. So get used to the idea that even if you go for a walk in the Kettle Morraine State Forest, at Bong State Recreation Area, along the Fox River, or in other wooded portions of Racine County, you're not necessarily safe from ticks and Lyme disease.

It used to be that the deer ticks which carry Lyme disease were something we thought of only during visits to the north woods, and one could almost draw a line along the Wisconsin River and know that the danger lay west and north. Now a recently compiled survey has found that the deer ticks have crept eastward and southward in Wisconsin. Creeping isn't really the word. Ticks hitchhike.

"It's possible that people and their dogs move them around," said Susan Paskewitz, a professor of entomology at the University of Wisconsin-Madison and the person who headed the tick survey. "I think that birds are really likely. Studies have shown the birds moving up and down the flyway during the migration season can actually transfer them pretty long distances. And of course the deer can, too."

Every year, Paskewitz said, university entomologists receive specimens of the lone star tick sent in by Wisconsin residents. Named for the prominent white dot on its back, the tick is native to the southern and southeastern United States. It's likely that these insects are picked up by people or their pets while traveling, then drop off and are found when the people return to Wisconsin, Paskewitz said. "We've already gotten our first one in this year."

Last fall, Paskewitz said, her group hired students from various universities, including the University of Wisconsin-Parkside, to go to state deer registration stations and examine some of the dead animals for ticks.

A comparison with the last survey, about nine years ago, showed that many eastern counties have ticks now with some being heavily infested, she said.

"For example, in Waukesha County and Walworth County where before every other time we've looked in those areas we haven't seen anything on deer … this time we really did."

The only survey spot in Racine and Kenosha counties was at Paddock Lake. Only 20 deer were brought in on the day of the survey, Paskewitz said, but the habitat is right. Checks of Bong - done by dragging a trap through the grass - have found only dog ticks.

What worries Paskewitz is the pattern of the spread. There's typically a lag between the establishment of a tick population and a subsequent surge in the number of Lyme disease cases, she said. Portage, Waushara, Marquette and Adams counties in central Wisconsin are all now showing significant increases in the number of Lyme disease cases.

"So that's why I'm a little concerned over what we may see over the next 10 to 15 years in southeastern Wisconsin."

In Illinois, the state health department reports that deer ticks are believed to be established in Cook, DuPage and Will counties around Chicago, and that ticks may be established in Lake County right across the Wisconsin border.

This becomes important for people going to wooded parks in Wisconsin or in Illinois. Many city parks may be infested with ticks, Paskewitz said. So people need to exercise caution there, and also on their own properties if they adjoin wooded areas.

There really aren't any new treatments for ticks or Lyme disease, said Stephanie Marquis, spokeswoman for the state Department of Health Services.

"What we really try to promote is prevention."

The advice hasn't changed, she said. Wear long pants and tuck them into your shoes or boots. Use a good repellent such as those containing DEET.

"The old preventions are really the best, avoiding wooded areas, long-grass areas. Try to stay on trails when you visit parks," she said.

You can also create a barrier around a home or cottage by using bark or rocks. Ticks are forest creatures and can be dried out by heat.

"Short grass helps, but, again, if you have a property that buts up against woods or tall grass, if you can create some kind of boundary there it can make it more difficult for them to get into your yard," Marquis said.

Alternate critters

Although the ticks are named for and associated with deer, one doesn't need deer to keep the life cycle of the Lyme organism going, Paskewitz said. There is evidence that it can exist in chipmunks and that they can become a living reservoir, infecting successive generations of ticks.

There is more work to be done. Paskewitz is preparing the results of her survey for publication in a scientific journal, and in conjunction with the U.S. Centers for Disease Control and Prevention she'll be doing a project in the Kettle Moraine State Forest to assess how much people know about ticks and their risk of exposure to Lyme disease. This summer she'll also be starting a project to collect ticks and examine how many are infected with the Lyme disease organism and whether that changes over time.

For the rest of us, the word is caution. We have to be careful where there are ticks, and in Wisconsin that now means just about everywhere.

Found a tick?

If you've found a deer tick on yourself after walking somewhere in Racine County, entomologist Susan Paskewitz of the University of Wisconsin-Madison would like to know. You may call her at (608) 262-1269, but a more reliable method is e-mail: paskewit@entomology.wisc.edu

By the Numbers

9,154 - Total Lyme disease cases in Wisconsin 2000-07

18 - Total number of Lyme cases in Racine County 2000-07

591 - Cases in Portage County, the county with the highest total

13.5 - Lyme disease cases per 100,000 people in Wisconsin 1992-2006

8 - Wisconsin's rank by number of cases per 100,000 people

Sources: Wisconsin Department of Health Services, U.S. Centers for Disease Control and Prevention