A giant plush-toy tick hovers over Dr. Bobbi Pritt from atop the high-powered microscope at her Mayo Clinic office.

She pays it no mind as she examines slides of various parasites, describing each creature in a merry tone of voice.

"This one is the head of a tapeworm that lives inside your gut," she chirped. "It basically just gets longer and longer and it kind of just absorbs the food that you're eating. So you're eating for two."

Ewww.

That's how most people react when they see and hear about such creepy, crawly things. But not Pritt, director of the Mayo's Clinical Parasitology Lab and a world-renowned researcher of diseases caused by parasites.

She moves in for a closer look.

Though fascinated by all parasites, she has a special fondness for ticks, a main focus of her research. She recently was involved in a major discovery regarding Lyme disease: helping to identify a new species of bacteria that causes the disease in Minnesota and is transmitted to people by the black-legged tick.

"We can learn a lot from parasites," she said. "My primary goal in studying them is to learn how we can better diagnose parasitic infections and therefore improve patient lives."

Growing up in rural Vermont, Pritt was into bugs even as a child.

"I definitely liked to go out and play in the dirt, and pull up worms and stuff," she said. "I guess I wasn't scared of them. I thought they were fascinating."

Playing in the sandbox she shared with her younger sister, Julie, she would hold out her finger and try to coax bumblebees to land so she could pet them.

"She said they were really pretty," recalled Julie Pritt, of Rochester.

A natural educator

The natural world — especially its tiniest creatures — always captivated Bobbi Pritt.

"That was a fascination of hers for a very long time," Julie Pritt said, noting that her sister also had an urge to share this knowledge with whomever was willing to listen. "She learned that other people would be fascinated. She wanted to educate them."

Her path to medicine was an unconventional one.

The first in her family to go to college, she started out at a community college, where she earned an associate degree in marketing. She went on to study biology at a four-year university before eventually heading to medical school at the University of Vermont. In between, she worked in graphic design for a 'zine aimed at girls.

Studying parasites was a way to merge both her passions — science and art.

"Parasites are very visually interesting," she said.

While doing a stint at the London College of Tropical Medicine about 10 years ago, Pritt started a blog on parasites. Calling herself "Parasite Gal," she began blogging about the exotic cases she was seeing in London to share with colleagues back in the United States.

The blog — dubbed "Creepy, Dreadful, Wonderful Parasites" — became her way of dashing off a wish-you-were-here postcard to fellow parasitologists. Soon it was drawing interest from nonscientists who were fascinated by the photos and descriptions of interesting bugs she was finding.

She still blogs. She regularly posts a "Case of the Week," inviting visitors to try to diagnose the disease and identify the culprit. Many are cases that Pritt and her team at the Mayo Clinic are investigating. But people from around the world also submit case studies.

Bins of bugs

At the Mayo lab are thousands of specimens collected over many years from all over the globe.

Standing in the lab in her white coat and blue gloves to prevent infection, Pritt showed off some of the samples from what she affectionately calls "the cabinet of wonders."

She held up a jar containing what looked like a very large rubber band. It was a single tapeworm taken from someone's intestine. She pulled out another jar, which she called the snow globe of ticks, and then demonstrated — shaking its contents and watching the ticks swirl and float to the bottom.

"We're really lucky," she said of the wide array of specimens available at the lab. "It's great for teaching."

Curiosity is what drives her to study parasites and to educate others about them, her sister said. And her graphic design background leads to unusual ways of doing that.

Take, for instance, the parasite wall calendar. Pritt collected close-up, artful images of lice, mites, bedbugs, ticks and tapeworms and turned them into a 12-month wall calendar that she gave as Christmas presents to friends and family members last year.

She also has designed parasite cellphone cases – likewise decorated with whimsical designs that come from her creepy-crawly slide collection.

Both the calendars and the phone cases were a hit, said her husband, Alex Ball.

"You'd be surprised at how many people – once they know Bobbi and her work – say that's fascinating. Then they'll want to sit down with her and talk to her and ask her to explain it all," he said.

At the same time, all that parasite expertise has its drawbacks, he said.

"The dinner table conversation occasionally can go astray when you live with a microbiologist."

Tracking Lyme disease

Despite the lighthearted air she often exudes, there's an ultraserious side to Pritt's work, too.

Earlier this year, she and her colleagues discovered a new strain of Lyme disease that does not produce the bull's-eye rash that typically alerts people to the condition. They were able to identify a different set of symptoms, a major development because when not caught and treated early, Lyme disease can be very serious.

Before the discovery, scientists knew of only one kind of bacteria — Borrelia burgdorferi — that caused the disease. But the Mayo team detected a different type of bacteria in the bloodstream of six local patients with Lyme disease.

In the course of the investigation that led to the discovery, Pritt said she learned how to go out in the field and collect ticks. It's called dragging for ticks, she said, and involves taking a big sheet of white flannel out into the woods.

"Ticks essentially will climb to the nearest blade of grass. So they'll climb up to the top and they'll stick their little legs out. They essentially wait for anything to walk by," she explained. "If something walks by, it grabs on."

"So that's actually how you collect them. You go out with the sheet, you drag it along, and the ticks will grab on. Then you hold up the sheet, you pick them off, you identify them and bring them back to the lab and test them," she said.

"I own a little bit of property in Wisconsin where I go up for fun, and that's now become one of the things I do when I go up there — I drag for ticks."

Allie Shah • 612-673-4488

@allieshah