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N.D. deer tick tests positive for Lyme disease

Researchers studying deer ticks in North Dakota have confirmed Lyme disease in one of the ticks captured during a research project that began last spring.

Researchers studying deer ticks in North Dakota have confirmed Lyme disease in one of the ticks captured during a research project that began last spring.

The tick-transmitted disease can affect the skin, nervous system, heart and joints.

According to Nate Russart, a UND graduate student working on the tick study, Lyme disease was confirmed in a single adult deer tick captured in Steele County. Researchers sampled 92 deer ticks, mostly in eastern North Dakota, and none of the other ticks tested positive for the disease, Russart said.

The study marks the first time deer ticks have been confirmed in North Dakota.

Relatively common in Minnesota, which has more of the forested habitat deer ticks prefer, Lyme disease remains uncommon in North Dakota. But more cases have shown up in recent years. According to the North Dakota Department of Health, the state had 15 confirmed or suspected cases of Lyme disease in 2009, along with 11 cases in 2008, 12 cases in 2007 and seven cases in 2006.

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From 2000 to 2005, North Dakota had no more than three cases, and there were no reports of Lyme disease in 2001, 2003 and 2004, the health department said.

Minnesota, by comparison, has averaged 900 to more than 1,200 Lyme disease cases since 2005, according to statistics from the state health department.

No surprise

Russart said he wasn't surprised to find Lyme disease in one of the deer ticks. If anything, he said he would have expected more of the ticks to test positive.

"It might indicate the ticks have moved into the area, and the Lyme disease hasn't yet, but that's just speculation," Russart said. "Our sample size isn't really big enough to draw those kinds of conclusions."

Dr. Jennifer Cope, an epidemiologist for the state Health Department in Bismarck, said the confirmed presence of deer ticks is the most important finding in the study so far. Even though tests found only one tick with Lyme disease, she said the presence of the ticks in North Dakota means there's potential for more cases of the disease.

The goal, she said, is to educate clinicians who might not routinely diagnose Lyme disease to be on the lookout.

"The potential (for Lyme disease) is there; we have the vector, so that's probably the most important message," Cope said. "If treated early, it's a very curable disease."

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Cope said additional research is planned for next year.

"We have a baseline now, and we'd like to get to different areas" to sample for deer ticks, she said.

The state Health and Game and Fish departments helped fund the study, which also includes researchers from North Dakota State University.

Sampling ticks

As part of the project, researchers sampled for ticks by dragging white sheets through vegetation -- a process called "flagging" or "dragging" -- and by trapping small mammals such as mice and checking for ticks.

Russart said most of the deer ticks were on the small mammals, and they found the ticks in the larval, nymph and adult stages. Researchers also captured hundreds of the larger, more common dog ticks, or wood ticks, which Russart said will be tested for other diseases. Wood ticks are known to carry diseases such as Rocky Mountain spotted fever but not Lyme disease.

Russart said he also plans to test the deer ticks for other diseases.

"So far, all I've tested are the deer ticks for Lyme disease," he said.

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Russart said he made two sweeps across the state collecting ticks, along with additional sampling closer to Grand Forks, and the deer ticks were most abundant in northeastern North Dakota. He said Grand Forks County had more adult deer ticks than anywhere else in the state, and the researchers found a high number of larval deer ticks in Grahams Island State Park.

Definitely here

It's difficult to say, he said, whether Grahams Island has a higher proportion of deer ticks or if he just happened to stumble onto a hotspot. He also said he can't conclude deer ticks are becoming more abundant in the state, but the findings confirm they're here.

"It seems like they are spreading," he said. "Just from talking to people, there was kind of a notion there weren't any deer ticks in the state. It's been shown in other areas that they've been spreading, and I think the same thing is happening" in North Dakota.

Russart said two deer hunters -- one in Minnesota and one in North Dakota -- brought him ticks this week that he confirmed as deer ticks.

"I heard other people say they saw some, too," he said. "So, obviously, they're out there; it's warm enough for them yet."

Meanwhile, Russart said, people who spend a lot of time outdoors, especially in more forested areas, should be aware of the potential for encountering deer ticks west of the Red River.

Adult deer ticks are about half the size of a wood tick, and the nymph and larval stages are even smaller.

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"There are deer ticks, and we have Lyme disease in the state," Russart said. "There might not be a very high prevalence of it, but it's possible, and people should make sure they check themselves after they've been outside."

N.D. lyme disease cases

Here's a look at the number of Lyme disease cases in North Dakota since 2000:

- 2000: Two.

- 2001: Zero.

- 2002: One.

- 2003: Zero.

- 2004: Zero.

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- 2005: Three.

- 2006: Seven.

- 2007: 12.

- 2008: 11.

- 2009: 15.

-- North Dakota Department of Health

Dokken reports on outdoors. Reach him at (701) 780-1148; (800) 477-6572, ext. 148; or send e-mail to bdokken@gfherald.com .

Brad Dokken joined the Herald company in November 1985 as a copy editor for Agweek magazine and has been the Grand Forks Herald's outdoors editor since 1998.

Besides his role as an outdoors writer, Dokken has an extensive background in northwest Minnesota and Canadian border issues and provides occasional coverage on those topics.

Reach him at bdokken@gfherald.com, by phone at (701) 780-1148 or on Twitter at @gfhoutdoor.
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