Local scientists are keeping tabs on ticks and Lyme disease


Call them by their scientific family names -- Ixodidae, Argasidae and Nuttalliellidae -- and ticks sound rather regal.

In reality, the thought or sight of any of these tiny members of the arachnid suborder is enough to make a mortal's skin crawl.

Ixodidae, the primary hard tick family, which includes the American dog tick (Dermacentor variabilis) and the blacklegged tick (Ixodes scapularis, aka deer tick), attach themselves to a host body to feed on its blood. Ticks are also known to carry different bacteria, which can be transmitted to the host while feeding.

There are hundreds of species of ticks in existence in the world, but only a few interact with humans.

It is the blacklegged tick that has gained notoriety in recent decades for carrying Borrelia burgdorferi, the pathogen responsible for causing Lyme disease, which has been found in both humans and some animals. Though the bacterium is found in white-tailed deer, it is more prevalent in mice, which blacklegged ticks feed on.

"Most people don't think much of them, but parasites are very fascinating animals if you just get over the fact one is crawling up your leg," said Thomas "Tom" Tyning, longtime professor of environmental science at Berkshire Community College in Pittsfield.

"A lot of them don't bother people. Ticks are very specific -- some are specific to mammals, some are specific to birds, some are specific to reptiles. For example, nobody would ever see bird ticks on them," he said.

Tyning regularly takes students on research and study trips through the county's fields and meadows, which are popular tick breeding and feeding grounds.

He and his classes take proper precautions like wearing long nylon pants and checking for ticks on their bodies after being in the field.

"If someone has a tick crawling on them, there's really no worry," said Tyning. "Not all ticks carry disease. It's the bacterium that infects, and [a tick] really has to get embedded into you for at least 48 hours for you to get sick."

About 15 years ago, Tyning learned about it firsthand when he contracted Lyme disease during a trip on Nantucket. He developed one of the classic telltale symptoms of Lyme -- a clear area at the site of the bite surrounded by a flat, red rash resembling a bullseye pattern.

He was prescribed the antibiotic doxycycline right away and has been Lyme-free since. Still, he keeps himself educated and takes preventative precautions when heading outside.

At the Center for Agriculture at the University of Massachusetts at Amherst, and at the UMass Laboratory for Medical Zoology, scientists believe research and prevention are key to better understanding ticks, the communicable diseases they carry, and learning how to protect people and pets from harmful pathogens.

Dr. Craig Hollingsworth of the Center's UMass Extension said there has been an increased tick population this spring. He said both adults and the young ticks, known as nymphs, have overwintered.

"Nymphs are generally dormant in the spring and most active in mid-summer, but some people are finding nymphs feeding on them even now," wrote Hollingsworth in an online article for UMass.

"So the ticks have been here all along, but when people become more active outdoors, we see more tick feeding," he said.

At the UMass Laboratory of Medical Zoology, scientists test tick specimens for about a dozen different kinds of tick-borne pathogens, including the Lyme disease-causing Borrelia burgdorferi. Specimens are sent in generally by private citizens who are bitten, but the lab also sees samples across the board, from veterinarians to municipal public health departments.

Test results from the tick are then recorded and added to a public database, so people can see what kinds of pathogens ticks are testing positive for in a given geographic region.

As animals and humans who host ticks move and migrate, so do tickborne diseases. Once a coastal organism found commonly on places like Cape Cod, ticks are now regularly found in places like Berkshire County.

"The first thing to know about [Lyme disease] is that it's really a disease of wildlife. It gets to us by accident," said lab director Dr. Stephen Rich, a professor of microbiology.

"In North Adams, for example, you wouldn't have found many ticks 15 to 20 years ago, and definitely not 30 years ago. Now, Berkshire County is used to seeing them," Rich said.

In the UMass medical zoology lab, researchers look at tick specimens from a genetic standpoint to understand how ticks and host species develop and transmit pathogens between one another.

Rich said unlike a mosquito, which draws blood much in the manner of a hypodermic needle, ticks use their hooked front legs and pincers to latch onto an organism and stay on it for days. In that position, the tick is able to "spit and slurp" saliva and other chemical secretions to maintain a "feeding lesion," thus "creating a perfect little environment" for pathogens to move between the tick and host.

The history of understanding tickborne diseases is relatively new.

"Right now our level of understanding of Lyme is pretty high. If you wound the clock back to the 1970s, we didn't know about Lyme," said Rich. It took scientists until the 1980s to understand the cause of and cycle of Lyme transmission.

Rich said in coming decades, researchers may learn that the multitudes of bacteria found in ticks could be causing other problems in humans.

For example, researchers at Yale University published a study this year after finding unique symptoms of infection in 18 patients in the Northeast. The disease was traced to the pathogen Borrelia miyamotoi, one which has been more commonly found among tick-bitten patients in Asia and Europe, not the U.S.

"We could be on the cusp of finding other diseases," said Rich. "Ticks are very dirty bugs, many of which are not carefully identified," which is why "it's important to have a whole-biology picture" of the subject.

"What's most important to know about Lyme disease is that it's preventable," said Rich. "That's the reason we engage in the work that we do. We feel like we're educating people, and that's what can make a difference."

Tick and Lyme disease resources

-- Lyme Alliance of the Berkshiresberkshirelyme.blogspot.com

-- "Lyme Disease in Massachusetts: A Report Issued by the Special Commission to Conduct an Investigation and Study of the Incidence and Impacts of Lyme Disease," published Feb. 28, 2013: http://1.usa.gov/13HJuEP

-- University of Massachusetts Laboratory of Medical Zoologywww.tickdiseases.org

-- University of Rhode Island TickEncounter Resource Center: www.tickencounter.org

-- Ticket Management Handbook of the Connecticut Agricultural Experiment Station (free download): http://1.usa.gov/EBsDy

-- Centers for Disease Control and Prevention: www.cdc.gov/ticks


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