Title

UND scientists prove Lyme disease is in Grand Forks County

Document Type

News Article

Publication Date

11-19-2014

Campus Unit

School of Medicine & Health Sciences

Abstract

GRAND FORKS, N.D.—University of North Dakota scientists warn that all of the variables for contracting Lyme disease are now present and established in Grand Forks County. Although eastern North Dakota borders Minnesota counties where the risk of contracting the tick-borne Lyme disease is moderate to high based on confirmed human cases, few studies have been done on the migration of the disease farther west.

Lyme disease is the most common tick-borne illness of humans in the United States, causing an estimated 300,000 cases per year. Lyme disease is a debilitating and significant public health problem that can result in arthritis, heart problems, and neurological impairment and disability. While Lyme disease can be treated effectively with antibiotics, some people continue to suffer with pain, fatigue, and memory problems called post-treatment Lyme disease syndrome.

Now, a joint research team, led by Professor Jefferson Vaughan, PhD, from the UND Department of Biology, and Assistant Professor Catherine Brissette, PhD, a biomedical scientist in the Department of Basic Sciences at the University of North Dakota School of Medicine and Health Sciences, reports they have verified that Lyme disease has spread to Grand Forks County. Brissette's laboratory works on the causative agent of Lyme disease, the bacterium Borrelia burgdorferi.

"Jeff Vaughan's student, Nate Russart, a UND graduate student in biology, was surveying ticks and tick-borne pathogens across the state of North Dakota," Brissette said.

This included trapping small rodents (mice and voles) in order to collect ticks. Russart had detected Borrelia burgdorferi DNA in black-legged, or deer, ticks (Ixodes) from Grand Forks County. Russart's work was recently published in the Journal of Medical Entomology at http://www.ncbi.nlm.nih.gov/pubmed/25276942.

"This suggested that the Lyme disease bacterium was in our area," Brissette said. "But it didn't prove that getting bitten by one of these ticks would transmit the Lyme disease bacterium. We wondered if we could isolate live B. burgdorferi bacteria from those local mice or voles."

"We were able to isolate live B. burgdorferi from the hearts of mice and voles from the Forest River and Turtle River areas of Grand Forks County," she said. "We showed that these bacteria were indeed the Lyme disease bacterium. We were also able to show that these bacteria were related closely to B. burgdorferi from Minnesota, Wisconsin, and eastern Manitoba, demonstrating that B. burgdorferi has migrated westward.”

Next the research team tested the ability of these bacteria to transmit disease. In nature, female ticks feed on deer, and then lay their eggs. When the eggs hatch, the larval ticks do not carry the Lyme disease bacterium. The larval ticks only become infected if they feed on an infected animal; usually a mouse or other small rodent. These ticks will feed, and then molt to the next life stage called a nymph. Infected nymphs can then transmit the infection to another small mammal (thus maintaining the bacterium in the environment); the nymphs can feed on an end host, like a person or pet. To test and prove that local bacteria were infectious, the research team looked at each stage of the infectious cycle in the laboratory.

"Prevention is key," Brissette said. "The ticks are very small, the size of a poppy seed. The tick has to feed for at least 24 hours before it can transmit the Lyme disease bacterium, so it's important to check yourself carefully for ticks after being in the woods. Wearing long sleeves and pants can help, as well as using repellents that contain DEET. Most people become infected in the summer months; you may notice an expanding rash from the site of the tick bite. Early Lyme disease is characterized by flu-like symptoms, like feeling tired, and achy all over. There is a vaccine for dogs, but unfortunately not for people. Lyme disease is treatable with antibiotics—the earlier, the better."

She said people who live in or visit eastern North Dakota shouldn't be complacent about Lyme disease. "The risk isn't high at this point, but—."

For future research, Vaughan is interested in whether voles might be an important reservoir in our area for the Lyme disease bacterium. Brissette is interested in what other bacteria or viruses these ticks might carry, and how that influences the transmission of disease.

"We would like to know if having multiple disease-causing agents in one tick increases the likelihood of someone getting sick, or decrease their chances of getting a particular infection," she said "We are also interested in whether being bitten by a tick with multiple pathogens affects the severity of disease—are people sicker if they contract Lyme disease and another tick-borne pathogen at the same time?"

The research paper titled "The Western Progression of Lyme Disease: Infectious and Non-clonal Borrelia burgdorferi sensu lato Populations in Grand Forks County, North Dakota" is available online from the Journal of Applied and Environmental Microbiology at http://aem.asm.org/content/early/2014/10/06/AEM.02422-14.abstract. Authors of the paper were Nathan M. Russart, MS, and Jefferson A. Vaughan from the UND Department of Biology, and Brandee L. Stone, MS, Robert A. Gaultney, Angela M. Floden, and Catherine Brissette from the Department of Basic Sciences at the UND SMHS.

Funding for the research was supported, in whole or in part, by grants from ND EPSCoR—the North Dakota Experimental Program to Stimulate Competitive Research, and grants to Brissette from UND SMHS start-up funds.

For more information about prevention, please visit the North Dakota Department of Health's website "Tickborne Diseases" at http://www.ndhealth.gov/disease/tickborne/default.htm.

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