Scientists Seek Solutions to the Ever-Growing Problem of Ticks — and the Diseases They Carry 

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• Courtesy Of Sophie Allen
• From left: Bill Landesman with students Jess Beliveau and Kali Wooster

Not many years ago, it was unusual to encounter a tick in the Northeast Kingdom. Now the blood-sucking arachnids are a fact of life at the NorthWoods Stewardship Center in East Charleston.

NorthWoods provides training for environmental conservation workers on 1,500 mostly wooded acres just outside Island Pond. Crew members who work in the forest undergrowth regularly discover that the tiny invaders have found their way through socks and pants to latch on for a blood meal.

"The record we have had in the last few years is somebody had 15 ticks on them at one time," said Maria Young, the nonprofit's executive director.

That's a worry, because some of those hitchhikers are black-legged ticks — also known as deer ticks — that are carrying Lyme disease, the bacterial infection often characterized by a bull's-eye rash. The infection, treated by antibiotics, can cause a scary range of ills, including fever, rash, facial paralysis and arthritis. Cases of Lyme have nearly doubled nationwide since 1991, and the problem is accelerating particularly fast in Vermont, where the incidence of the disease is among the highest in the country.

For many Vermonters, the prospect of catching a tick-borne disease has put a damper on outdoor activity. When Young works with school groups, she notices that a fear of ticks distracts some kids from the experience.

"What makes me sad is I see it with those folks who are not as comfortable in the outdoors already," Young said. "It sets up another barrier."

It's not just young people. David Munyak, owner of 30 rural acres in Middletown Springs, speaks for many when he says, "I find myself reluctant to go out in the woods during tick season."

Munyak, who once picked 18 ticks off his clothes and body after doing some brush hogging, contracted a serious case of Lyme disease a few years ago.

"I had every single symptom that is part of it: the aches, the chills, the fever, the fatigue. It was horrible," said Munyak, who thinks Lyme also caused him memory and cognition problems.

"I don't ever want to have Lyme disease like that again," he said.

Researchers across New England are looking for ways to allay such fears. Alarm over the tick population explosion and its threat to public health has spurred a huge increase in studies of tick ecology and epidemiology. The goal of much of this research: to give property owners and outdoor enthusiasts effective strategies to reduce the risk of a tick bite.

Full answers are likely some way off. Scientists caution that they're far from certain about how many ticks there are, where they are and how to control their numbers. It's not even clear how much the tick population has grown in recent years — there just aren't enough baseline data to draw a conclusion.

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• Courtesy Of Sophie Allen
• Vial of ticks

But this year, researchers in New England are tackling one potentially fruitful avenue of inquiry. They have launched a region-wide survey to understand what techniques landowners are using — including chemical spraying and other treatments — to suppress tick populations, and which are most effective.

Many of the projects are happening through the New England Center of Excellence in Vector-Borne Diseases at the University of Massachusetts Amherst. The center's research, which started last July, marks the first time so many biologists in the region have joined forces to work on the issue of tick-borne diseases.

The Vermont leader in this work is Bill Landesman, an associate professor of biology who studies tick ecology at Northern Vermont University-Johnson. Landesman and his counterparts are surveying property owners this spring as part of a study called "Is Tick Control Helping?" or Project ITCH. They will visit some respondents' homes repeatedly over four years to assess tick populations by dragging a white piece of fabric across the ground, or carrying a flag that touches shrubs, and counting the number of ticks they pick up. The resulting data will help assess how residents' tick-control measures are working.

"We know from other studies that some measures are more effective than others, but there's a lack of good information on what works," said University of Rhode Island entomology professor Thomas Mather, an ITCH investigator.

When Landesman advertised his survey on Front Porch Forum, hundreds of Vermonters got in touch. But he's been studying ticks in his lab and in the field since long before ITCH. Student lab assistants help him grind up the tick samples and extract the DNA. He stores his collection of whole ticks from his years in the field, and also tick DNA, in a freezer in his lab.

For the past decade, he's been sampling parasitic populations at six sites in Rutland County. One is Munyak's home in Middletown Springs. There, Landesman has found that some invasive species, such as Japanese barberry, garlic mustard, and bush honeysuckle, seem to be associated with larger tick populations. When Munyak removed those plants, Landesman said, tick numbers appeared to drop precipitously.

"After we start doing some kind of intervention, we can see the effects of vegetation removal on the number of ticks in a forest," he said.

It irritates Mather, the University of Rhode Island researcher, to hear unscientific tick mitigation suggestions. He's director of the university's online tick information center, TickEncounter, so he has heard plenty of questionable theories. A common one is that chickens, opossums or guinea hens can be deployed to eat the ticks. The use of opossums is based on one poorly executed study, he said.

"People say, 'I'm not going to spray anything; I'm going to get me some opossums,'" Mather said. "Really? You're going to drive down to Walmart and pick some up? How are you going to orchestrate that? Opossums have their own mind, and they're not going to hang out on your land."

While chickens do eat insects and spiders, he noted, domestic fowl also serve as hosts for ticks.

"Residential tick control is kind of a Wild West activity right now," said Mather, who sprays the pesticide permethrin in his own yard. "People are making assumptions about what they want to work."

Pest control companies and many scientists say spraying permethrin in brush and grass is the most effective way to kill ticks, which live for two or three years, feeding on different hosts. But there's concern that the chemicals are killing beneficial insects and spiders.

Ecologist Jason Hill from the Vermont Center for Ecostudies is hoping to find out more. Earlier this month, he launched a study of tick control and heard from hundreds of property owners who offered their land for surveying purposes.

"There is a tremendous interest in what is driving global declines of insect populations and what we as homeowners can do to stop that," he said.

Hill will make several visits and count ticks at properties that have been sprayed with pesticides or alternatives such as organic oils. He'll also assess properties that haven't been treated at all.

"Hopefully, by surveying enough properties, we'll see if there is a reduction, or no change at all, in the number of ticks and the number of insects we encounter," Hill said.

The University of Vermont is studying alternatives to the chemical pesticides, including a granular fungus that lives in the soil and can kill tick larvae. Spraying it on bushes and grass is one possible management tool, according to Cheryl Frank Sullivan, a researcher at UVM's Entomology Research Laboratory.

Lyme disease isn't the only concern. The bacterium anaplasmosis is now the second most common tick-borne disease in Vermont. Babesiosis, a tick-borne disease that can be fatal, has become endemic. And the state has also seen alpha-gal syndrome, an allergic reaction to red meat that is triggered by a bite from the lone star tick — a native of the southern U.S. that has been found in Vermont.

Clinical trials are under way for new vaccines against Lyme disease, but so far there's nothing on the market that can prevent it in humans.

Teaching people to identify ticks could reduce some of the fear around them, said Mather, whose TickEncounter website lists best practices for dealing with the parasites. For example, if you know what kind of tick has latched on, it's easier to assess the risk of disease. Black-legged ticks have black or dark brown legs, a reddish-brown body, and a black shield on the back.

It's also important to know the tick's stage of life, because that has a bearing on the likelihood of infection. Scientists think most Lyme disease is transmitted by ticks at the nymph stage, in May and June, when the arachnids are tiny and more difficult to detect.

For those who detach a tick, Mather recommends sending the body in to the University of Rhode Island's TickSpotters program to get a risk assessment. As for prevention, he said, it helps to walk in the center of the trail, not near the underbrush, and wear light-colored clothes to make it easier to spot ticks. Tucking pants into socks, and shirt into pants, can keep them from crawling under clothes. Permethrin applied to clothes is the most effective repellent, he said; it kills the bugs and stays effective even after clothes are washed.

Hill, the Vermont Center for Ecostudies researcher, recommends preparation, acceptance and management. He estimated that he pulls about 50 ticks off his body and clothing after a typical day in the field. If he walks through a brushy area in May or June, he emerges covered in black-legged tick nymphs.

"It looks like somebody has thrown thousands of chia seeds against your pants," he said.

Tick populations will continue to grow as it gets warmer year-round, Hill said. When people tell him they've stopped using their yards because of the parasites, he counsels that with education and adaptation, they can go back outside.

Sullivan agreed that acceptance is key. Awareness is, too, she said.

"There's no one silver bullet to manage ticks," Sullivan said. "Chemical pesticides or biological pesticides are one tool in the tick management kit, paired with surveillance on yourself and your pets."

The Tick Top 10

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• Courtesy Of Cheryl Frank Sullivan
• Female black-legged tick with dime

Thomas Mather is director of the University of Rhode Island's Centerfor Vector-Borne Disease and its TickEncounter resource center. Here are the 10 things Mather thinks everyone should know about ticks.

1. Ticks crawl up.
Ticks don't jump, fly or drop from trees. If you find one attached to your head or back, it likely crawled up your body to get there.

2. All ticks, including deer ticks, come in small, medium and large sizes.
Ticks hatch from eggs and develop through three active (and blood-feeding) stages: larvae (when they are the size of a grain of sand); nymphs (when they're the size of a poppy seed); and adults (when they're the size of an apple seed). Ticks bigger than that are probably full, or partly full, of blood.

3. Ticks can be active in winter.
Adult-stage deer ticks become active after the first frost. They're not killed by freezing temperatures, and they're active any winter day that the ground is not frozen or covered in snow.

4. Ticks carry disease-causing microbes.
Scientists are finding ever more disease-causing microbes transmitted by ticks. These days, a tick bite is much more likely than in the past to make you sick.

5. Only deer ticks transmit Lyme disease bacteria.
The only way to get Lyme disease is to be bitten by a deer tick, also known as the black-legged tick, or by one of its close relations around the world. It's important to save any tick that bites you in order to identify it. Doing so can eliminate unnecessary doctor visits and treatments.

6. For most tick-borne diseases, you have at least 24 hours to find and remove a feeding tick before it transmits an infection.

7. Deer tick nymphs look like poppy seeds.
One out of four nymph-stage deer ticks carries nasty germs, including Lyme disease, in the northeastern, mid-Atlantic and upper midwestern states.

8. The easiest and safest way to remove a tick is with pointy tweezers.
A tick is a little germ-filled balloon. If you squeeze it too hard on the back end, the germs are pushed to the front end. Using pointy tweezers, pull the tick out like a splinter. Don't worry if the mouthpart stays in the skin, as long as the rest of the tick has been pulled out by its head. Other tick removal methods, such as a hot match, Vaseline, dish soap and cotton, and little key-like devices don't work as well or consistently as pointy tweezers. Remember to save the tick and try to identify it.

9. Wear clothing with built-in tick repellent.
Tick repellent should go on clothing, not skin. Commercially treated tick-repellent clothes last through several washes; using kits or sprays to treat your own outdoor wardrobe can last through six washes.

10. Tick-borne disease and tick bites are preventable.
Reducing tick abundance in your yard, wearing tick-repellent clothing, treating pets with tick-repellent products and doing body scans to find ticks can prevent tick bites.