UMass ‘tick lab’ tests pests for Lyme, but cautions reading too much into results

Last modified: Tuesday, June 24, 2014
The UMass Laboratory of Medical Zoology in Fernald Hall gets a lot of mail. In the spring and fall — the busiest times of year — that means about 100 to 200 pieces of mail a day.

Most people wouldn’t be excited to be spammed with envelopes full of ticks, but this laboratory is in the business of testing people’s ticks. And business is good.

People from all over the country are continually mailing ticks of all varieties to the lab to get tested for the bacteria that causes Lyme disease, among other things. Those who pay $50 to have a tick tested get the results in about five days, and the scientists at the University of Massachusetts Laboratory of Medical Zoology get data to help track the spread of Lyme and other pathogens. The lab staff also provide the data to local public health agencies and make it available to the public on the lab’s website, www.tickdiseases.org. Scientists at the lab also study malaria.

Lyme disease, most commonly associated with symptoms including fever, joint pain, fatigue and a bulls-eye rash, has become much more common in the western part of the state over the last 10 years, Rich said. About 30,000 cases of Lyme are reported to the Center for Disease Control each year in the U.S., with almost cases concentrated in the Northeast and upper Midwest.

Uptick in testing

With concern about Lyme disease rising to a fever pitch in the Connecticut River Valley, it’s not surprising that more and more people are taking advantage of the service. The incoming number of ticks has doubled every year since the lab opened in 2006, said Stephen Rich, director of the laboratory. But this year, he expects the number to triple or quadruple.

Also expected to increase the number of submissions is a $110,000 state grant that will allow people in 32 communities to get ticks tested for free this year and next. In western Massachusetts, that includes the Franklin County towns of Buckland, Charlemont, Conway, Deerfield, Gill, Hawley, Heath, Leyden, Monroe and Shelburne.

Scientifically speaking, it is a very good thing that the number of people sending ticks is growing, Rich said. The data the lab is producing becomes more accurate as the pool of samples gets bigger.

“Now, we’re getting 100 ticks from a town, which we could never get before,” he said.

People can type in their zip codes at stats.tickdiseases.org and see what percentage of ticks tested from their city or town carried Lyme and if rarer tick-borne diseases are in their area.

While the data is certainly valuable for the public, Rich said one of the dilemmas of running a tick lab is how to ensure that the people who pay to have a tick tested are taking a balanced look at the results. Those reading the results need to recognize what they mean, but also what they do not mean.

“Just because you had a tick carrying the pathogen does not mean you have Lyme,” said Lora Miller, an undergraduate environmental science student who was working at the lab Friday. Your immune system may have fought off the infection, she explained, or the tick may not have transmitted the bacteria that causes Lyme, Borrelia burgdorferi. Depending on which expert you ask, there is a 12- to 48-hour window before the tick transmits the bacteria.

At the same time, someone could get a clean test result from a tick they submitted, yet still have Lyme disease from a different tick or an old infection, he said.

“We go out of our way to tell people, ‘Don’t make your decision based on the results of a tick test,’ ” Rich said. If people use the results as the basis for stopping antibiotic treatment or giving up on any other diagnosis, the results are not helpful, but harmful, he said.

Rich said he knew this would be a problem when he launched the lab in 2006.

“I was pretty squeamish about it because my colleagues said, ‘it isn’t useful information,’” he said. “But I think it does provide useful information,” from the species of ticks that are living in an area to the percentage of ticks that are infected.

As more symptoms become linked to Lyme disease — some experts say gastrointestinal, neurological and psychiatric problems can plague Lyme victims for years after they were first infected — that may mean more people to take their positive tick result as a diagnosis for what ails them.

But, Rich said, a test result used the right way can be an important tool for doctors to use in making decisions about testing, diagnosing and treating their patients.

“A lot of doctors do like to have that information,” said Elisheva Neffinger, a lab employee who recently graduated with a degree in plant, soil and insect sciences.

Other illnesses

Test results that are positive for the more rare tick-borne diseases Babesiosis and Anaplasmosis can be especially helpful for doctors, Rich said, because the incidence in this area is less than 5 percent. Both diseases have some symptoms in common with Lyme and can be fatal if the victim has a weakened immune system.

If someone is sick with anaplasmosis, not many doctors around here would be likely to put the symptoms together and come up with the correct diagnosis just because it is so rare, he said. “But if you go in with a tick that bit you and it has tested positive for anaplasmosis, that opens the conversation,” he said.

Unlike Lyme tests for humans, which can produce false positive and negative results, the DNA test the tick lab uses is 99.9 percent accurate.

After the ticks are photographed under a microscope, a lab worker puts them into a machine that extracts the DNA. “We crush up and extract all the DNA that is in the tick, including any bacteria,” such as the bacteria that causes Lyme, Miller said in the lab Friday.

The DNA test is very accurate because it uses the whole tick, Miller said, and that is why it is not practical for use on humans. “You could take a DNA sample from a human and test it... but you can’t say where the Lyme is going to be in the body on any given day,” she said.

Once the DNA is extracted, a lab worker puts it into a tray that holds 96 samples, adds “primers” that amplify the DNA of whatever kind of bacteria they are looking for, and puts it into a machine that graphs the DNA on a computer screen. The graph will show the tick’s DNA as well as the DNA of any other bacteria it is carrying. They test for different tick-borne pathogens depending on the kind of tick, Miller said.

People often ask if the lab can test old or damaged ticks, “and the answer is always ‘yes,’ ” she said. “DNA is really stable, so it could be 50 years old and we could test it,” Miller said. The samples are saved in a freezer, so people can order different tests in the future.

Talking ticks

For the first time this year, the Laboratory of Medical Zoology is staffing its office at 102 Fernald Hall between 10 a.m. and 4 p.m. Monday through Friday so that people can drop off ticks in person and talk to lab staff, Rich said.

He hopes that the face-to-face contact with people submitting ticks will be a good opportunity for staff to drive home the message that the results are not diagnoses.

And while staff won’t be handing out medical advice, they can give tips, data, and other information to anyone looking to get educated on tick-borne diseases.

Miller said one of the most frequent pieces of advice she gives people is, “if you find a tick, don’t panic.”

“We live in an area with lots of ticks, so it’s probably going to happen,” she said. “If it bit you, it’s always a good idea to consult a doctor and monitor the tick bite area for a rash, and be aware for any signs of illness.”

Miller said that while trying to diagnose and treat Lyme can be difficult, preventing tick bites is straight forward. “I just check myself,” she said. Wearing light colored clothes can help, she said, and if she thinks there may be ticks on her clothes, she puts them in the dryer for 20 minutes to kill the pests. Insecticides like permethrin will kill ticks if applied to clothes, but not everyone likes the idea of dousing their clothes in chemicals, she said.

Rebecca Everett can be reached at reverett@gazettenet.com.