Here & Now

Earlier Spring Start for Deer Tick Nymphs Spurs Lyme Disease

Frederica Freyberg:

In other news, tick populations in Wisconsin have been growing slowly for decades. This spring, however, new and early activity has the attention of scientists who study these tiny carriers of disease. Marisa Wojcik took a walk in the woods with UW entomologist and director of the Upper Midwestern Center of Excellence for Vector-Borne Disease, Susan Paskewitz, to learn more.

Susan Paskewitz:

We’re seeing more ticks in more places.

Marisa Wojcik:

Susan Paskewitz’s job is to seek out the crawling creatures that make the rest of us cringe. Ticks.

Susan Paskewitz:

They’ve invaded a lot of locations in the state where we didn’t used to be able to find them and that’s particularly down in the southern quarter and then the eastern, say, quarter to third of the state. The immature stages are either going to be really low so down here in the leaf litter, they may be up on some of this vegetation, and our research really focuses on what increases people’s risk of exposure and then, two, what can we do about it.

Marisa Wojcik:

She drags her white canvas over the forest floor to find these minuscule parasites.

Susan Paskewitz:

They are very much associated with wooded locations.

Marisa Wojcik:

And the research points to a growing population.

Susan Paskewitz:

Ten, twenty years ago, maybe 50 of the 72 Wisconsin counties had an established population of deer ticks and now there’s only one county where we don’t find them.

Marisa Wojcik:

While that growth has taken decades, this spring, there’s a new development.

Susan Paskewitz:

One new thing we’ve seen this year is earlier activity of the juvenile stage that we call a nymph.

Marisa Wojcik:

Or, as she also referred to them, teenager ticks.

Susan Paskewitz:

The nymphs are the most important stage in terms of disease transmission and we think that that’s because they’re so much smaller than the adult deer ticks.

Marisa Wojcik:

Deer ticks are the smallest and most commonly known to spread Lyme disease.

Susan Paskewitz:

Adult deer ticks are big enough so that you’re going to feel them when they’re crawling on you, usually, or even if you don’t, when you’re checking your body, you may feel a little lump and so you recognize and you can remove those quickly. The nymphs, though, they really don’t trigger any kind of a response. You don’t feel them moving on you and they’re so small, like the size of a poppy seed or small freckle, they are actually hard to detect on your body.

Marisa Wojcik:

The earlier activity of the nymph means more chances to spread Lyme.

Susan Paskewitz:

This year, we saw nymphs in middle May for the first time so a good week to two weeks before we’d usually be able to pick them up, and that is probably related to warmer springs, warmer temperatures and they’re getting active earlier. In terms of Lyme disease, which is the disease that we see the most human cases in our state, we’ve been seeing a steady increase. I think last year, it was over 4,000 cases that were reported to the state.

Marisa Wojcik:

Lyme disease is usually spotted by a telltale sign.

Susan Paskewitz:

For people who get a bull’s-eye rash at the site of the tick bite or doesn’t always look like a bull’s-eye but a large rash there, it’s not hard. A doctor will know right away what that is and how to treat it.

Marisa Wojcik:

To help the human tussle with ticks, they’re using technology.

Susan Paskewitz:

The tick app is a research tool that we developed.

Marisa Wojcik:

To both educate people and learn more about where ticks and Lyme disease are being found.

Susan Paskewitz:

You’d have this option, if you did get any ticks on you, to take pictures, send them directly to the scientists. We can identify them, give you an estimate for how long the tick has been feeding and then make some suggestions about what you might want to do as your next steps. It also has some really great information in it that you can use to identify the tick yourself.

Marisa Wojcik:

And perhaps one day harness machine learning to identify ticks. In the meantime, researchers like Paskewitz are also learning about humans.

Susan Paskewitz:

Some of the things that we’ve learned from our tick app tool are that people maybe don’t really realize where they’re being exposed to ticks. An adult tick wouldn’t be on you for more than a week, seven days, and yet we have people telling us that they picked up ticks in places that they visited a couple of weeks ago. Many people are imagining that it’s when they go to their cabins or when they’re out in the woods hiking, instead of in their own yards.

Marisa Wojcik:

In spite of all this, she says that doesn’t mean that you can’t still get outdoors.

Susan Paskewitz:

We certainly want people to be out enjoying our beautiful woods in Wisconsin and not to be afraid to do that because of ticks, but they should just take the precautions to make sure that they, their kids, their pets are protected. Wearing light-colored clothing so that if you get a tick on you, you’d be able to see it against that background. If you potentially have some ticks that are on the clothing that maybe you don’t see, if you put them in the dryer at a high temperature for 20, 30 minutes that will take care of that. We also recommend that people use a repellant and that can be the same kind of repellants that you use for mosquito prevention, and then do a shower where you’re just removing anything that might be on your person, perhaps not yet attached and trying to feed.

Marisa Wojcik:

Reporting from the woods, I’m Marisa Wojcik for “Here & Now.”