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Ticks

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Although last winter was particularly severe both in its cold and snow cover, many Vineyarders complained early this summer that there were more ticks than ever. This is intriguing because the proliferation of these pests in earlier years was often ascribed to relatively mild winters. There may be other examples of such dubious assumptions, which have led to flawed proposals for controlling ticks.

The apparent contradiction of received wisdom about the arachnids reminded me of a campaign last year to reduce their number by slashing the Vineyard’s deer population (MV Times,  Aug. 29, 2013, “Sam Telford from Tufts talks tough on ticks”; Vineyard Gazette, Jan. 31, 2013). Although the main advocate for drastically reducing or extirpating deer, Sam Telford, has made a strong argument for re-approving the vaccine against the disease, which became yet another victim of our litigious culture when it was withdrawn from the market after lawsuits, my experience suggests that his direct linkage between the number of deer and cases of Lyme disease is weaker, and is based on a failure to compare different eco-systems.

Here’s the current doctrine: the main vector for Lyme disease is deer ticks — that much is certainly true — as Mr. Telford says, up to 94 percent of female ticks have fed on deer. This is where I become suspicious for a couple of reasons. First, because of the words “up to,” which indicate that there is a range. The second is because the specific numbers of both ticks and deer in such diverse environments as wetland forests and grasslands, and most importantly the ratio between them, is essential to understanding the true significance of any numbers, and the factors behind them. Ninety-four percent of 100 ticks per acre with two deer would be utterly different, to take an extreme example, in its impact on humans, than 94 percent of 10,000 ticks per acre with one deer.

My reasons for suspecting that Mr. Telford’s conclusions are based on an incomplete analysis are founded on decades of life outdoors on the Vineyard. Here’s what I’ve noticed. When my family and I walk along mown paths in oak forests between Menemsha and the Brickyard in June and July, we almost invariably pick up a few deer ticks, despite the fact that we can see for considerable distances under the trees, and deer are usually absent or sparse. But after 20 years and tens of thousands of hours of yard work and thrashing through brush in a sassafras, beech, maple and tupelo (Beetlebung) forest in Aquinnah during the same months, we have yet to pick up a single tick, although deer are visible all day long in an area with far more places to hide.

Mr. Telford might be tempted to respond that these observations are just the anecdotal experiences of one man and his family, but I’d suggest that the difference has been too great and consistent over decades to be easily dismissed. It would be wiser to find the reasons behind the observations than to dismiss them. Here’s my hypothesis.

The abundance of deer and near absence of ticks in Aquinnah’s lush wetland forest, and abundance of ticks despite a lower number of deer in Chilmark’s dry oak forest suggest that the differences go deeper than the relationship between deer and their parasites. In fact, it suggests that it has something to do with the types of forest. One of the chief differences between them is that oak forests produce more starch in the form of acorns that squirrels can hoard, leaving plenty for other rodents such as white-footed mice, which serve as the hosts for immature deer ticks. The mice are a crucial carrier of the ticks, which thrive, even when there aren’t many deer, if the rodents are plentiful.

The evidence from our forest in Aquinnah also suggests that the contrary is true — that the ticks nearly disappear when there are plenty of deer, but few mice. This difference has been so flagrant in my experience that I think the common term for Ixodes scapularis, “deer tick”, is a misnomer, which misdirects attention towards the wrong animal, just because it is a bigger and more obvious target. The ticks should probably be renamed the “white-footed mouse tick,” “oak tick,” or “acorn tick.”

This brings me to the question of good versus bad solutions. Mr. Telford “makes no bones that his primary short-term objective is to significantly reduce the deer population on the Island” by killing them. Perhaps he should watch a TED talk by Alan Savory in which Mr. Savory says that his greatest regret is that he told African governments to cull ten of thousands of elephants in order to manage their reserves, causing the extermination of 40,000 elephants, although his analysis turned out to be backwards.

There are two better ways to reduce the number of Ixodes scapularis on the Island than unleashing a shooting-fest, one of which is so well-known that I was surprised that Mr. Telford did not mention it. It involves the use of tickicide-treated rollers at passive feeding stations for white-tailed deer. According to Cornell University, study after study (Carroll et al 2002, Pound et al 2000, Pound et al 2000b, Solberg et al 2003) has shown large reductions in tick populations following the use of such devices.

Another entirely compatible solution would be to favor vegetation that does not produce surplus starch for mice. I imagine that this solution would be preferable to people who would rather see a few trees removed from their views, than the disappearance of deer, which provide the countryside with much of its charm.

If I were a hunter, and I am indirectly, in the sense that I have allowed specific hunters to hunt on my land, I would also be opposed to Mr. Telford’s plan, since it would result in the rapid reduction of the very deer hunters enjoy stalking. It might be fun at first, but would end up destroying a pastime that many people enjoy.

One thing I agree on with Mr. Telford is that the problem of Lyme disease and other tick-borne diseases is huge and must be addressed. The question is simply, how? The answer is probably to attack the problem in several ways at once. One way is to continue encouraging sustainable hunting, since it plays a positive role in maintaining the Island’s ecological balance. Another way that should be implemented simultaneously is to install feeding stations or salt licks with tickicide-treated rollers in oak forests and other infested environments. A third one is to favor vegetation that does not encourage the proliferation of mice and their ticks. The fourth way, which Mr. Telford and I agree on whole-heartedly, is to push for the re-approval or improvement of the vaccine.

In the meantime, we should be wary of listening to any calls to manage nature through destructive intervention or violence, since such approaches have caused enormous unintended consequences in the past.

Duncan Caldwell is a Fellow at theMarine and Paleobiological Research Institute of Vineyard Haven and a Lecturer in prehistory, Doctoral module, Muséum National d’Histoire Naturelle, Paris.

Is this red bump a tick bite?

Three weeks ago I was bitten by a tick. I’m sure I got it off before 24 hours, but the bite mark is still red, about the size of a pea. It hasn’t grown in size. Is it unusual to have a bite mark for that long? Could it be that the proboscis is still in there?

Everybody reacts differently to tick or mosquito bites. Then again, everyone has a different reaction to watching Duck Dynasty. And, there are three possibilities to consider even with individual variation in response to tick bite: (1) The tick creates a small hole in your skin. Therefore, like sticking yourself with a fish hook, you could get a local infection from skin bacteria (cellulitis). Any streaks of redness coming from a bite could be cellulitis and need to be evaluated by your doctor. (2) You could be allergic…my bites itch like crazy for weeks.  Ticks leave a little bit of their exoskeleton in the bite (the microscopic backwards facing barbs on the mouthparts sometimes come off) and this attracts immune cells that can cause local redness and itching. Pulling a tick out usually leaves behind even more tick mouthpart materials. Although some may think it gross, it is no different than getting a splinter, which is usually walled off by your body so that it is harmless (splinters too can cause cellulitis which needs to be seen by a doctor; someone in Rhode Island just lost a limb due to flesh-eating bacteria from thorn prick cellulitis). Or, it simply works itself out, depending on how deep it is, because the skin is constantly shedding flakes of the outermost layers. This is why it does not matter if the tick “head” is left in. (3) It could be Tularemia. The Vineyard is uniquely blessed with having dog (wood) ticks (we could say the same about tourists) that are not uncommonly infected by the bacteria that cause Tularemia. Everyone knows about landscapers breathing it in, but it is naturally out there as a tick-transmitted infection. When you get Tularemia from a tick bite, a red area doesn’t enlarge much but turns into an ugly divot and your nearest lymph nodes get big. Usually you will also have a high fever. So any ugly red divot in your skin, nearby swollen glands, and fever needs to be checked out pronto by a doc.

Visit the MV Tick Borne Disease Initiative website, sponsored by the Island-wide boards of health (www.mvboh.org) for tips on prevention.

Sam Telford is Professor of Infectious Disease and Global Health at Tufts University Cummings School of Veterinary Medicine.

Why don’t nudists get Lyme disease?

Believe it or not, there was actually a small study reported in the New England Journal of Medicine back in the late 1980s claiming that nudists don’t get Lyme disease. Although no one has replicated the study, there are many reasons why a nudist might be less likely to get a tick bite. For one, nudists tend to avoid the brush habitat where there are deer ticks…poison ivy and greenbrier don’t go too well with certain body parts. Nudists may look at their skin or that of their fellow nudists frequently and find ticks easily. And, ticks tend to crawl around a lot on a body looking for a dark, clothing constricted place under which to attach. It could also be that nudists use more repellent (mosquito bites and certain body parts don’t mix either).  Perhaps the Vineyard boards of health should advocate for town officials “turning the other cheek” to episodes of public nudity, particularly in the woods. Get rid of those “no nudity” admonitions on all the Land Bank and other trailhead signs!

Nude or clothed, it is tick season and you should try to prevent tick bites.  Use repellents and treated clothing if you wear any.  Visit the MV Tick Borne Disease Initiative website, sponsored by the Island-wide boards of health (www.mvboh.org) for tips on prevention.

Sam Telford is Professor of Infectious Disease and Global Health at Tufts University Cummings School of Veterinary Medicine.

Should I use a lit cigarette to burn an attached tick off of my leg?

There is as much mythology about removing a tick as there is on catching a bluefish.

Over the years, I have known a guy to have burned a tick off his penis with a lit cigarette and a cut-happy surgeon to have cut a tick out of an upper arm, leaving a large divot. C’mon folks, it is just a tick bite. It is not like getting bitten by a taipan (a snake with a highly lethal bite) in the Australian outback, where there is some justification in immediately amputating the bitten body part. An attached tick does not need to be covered in Vaseline, allegedly because it suffocates the tick gradually so that it won’t get panicked and transmit microbes; this is baloney, the tick is not consciously transmitting and nothing you do will speed up or slow down the process. Ticks do not need to be poisoned by kerosene; nor do you need to buy a special tool that rotates the tick counterclockwise. Just pull it out. Use your fingers if you can.  Even better, use some fine forceps or tweezers and grasp the head as close to the skin as possible. Pull steadily upwards. It does not matter if you leave the “head” in, it will be walled off or work itself out like a splinter. You cannot squeeze a disease-causing microbe into you. The tick has a valve in its feeding tube (25-cent word:  pharyngeal valve) that only allows fluids to flow inward so that there is no regurgitation into the feeding cavity. The microbes that cause disease are delivered in tick spit. As you spit out your morning coffee thinking of ticks spitting into you, it should be noted that whereas our spit is a crude mix of starch digesting enzymes, mucus, water, and bacteria, tick spit has evolved over millions of years to contain chemicals that prevent blood from coagulating, immune cells from attacking the tick’s internal parts, and preventing inflammation and pain. This is why some of us believe that ticks are more highly evolved than those other notorious bloodsuckers…lawyers.

Tick bites can be prevented. Wear repellent or treat your clothing. Take a shower. Check for ticks. Visit the MV Tick Borne Disease Initiative website (www.mvboh.org) for tips on prevention.

Sam Telford is Professor of Infectious Disease and Global Health at Tufts University Cummings School of Veterinary Medicine. He is a member of the MV Tick Borne Disease Initiative, which is sponsored by the Island-wide boards of health.

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The riskiest time of the year for contracting Lyme disease is now, experts say.

In the springtime, the nymphal deer tick can be as small as a poppy seed. — Photo by Jim Gathany, Wikimedia

Lyme disease is the most prevalent vector-borne disease in the United States. An estimated 300,000 people contract it every year, and as many Islanders know, we live in a hot zone of the epidemic.

As winter finally loosens its icy grip, deer tick nymphs, the teenagers of the tick world, emerge en masse, hungry for the blood meal that will propel them to adulthood later in the summer. Approximately 30 percent of these nymphs have contracted Borrelia burgdorferi, the bacteria that causes Lyme disease, from the white-footed mice they cozied up with over the winter. Because they’re so small, roughly the size of a poppy seed, and because they excrete a natural anesthetic when they bite, deer tick nymphs are masters at avoiding detection. By the time these terrible teens reach adulthood in late summer, they will be responsible for about 90 percent of the Lyme disease contracted by humans.

Defense is key

“Spring and early summer is the time to use every weapon you have,” tick expert Dr. Sam Telford of Tufts University told The Times in a recent conversation. Mr. Telford has been studying ticks and tick-borne diseases on Nantucket and Martha’s Vineyard for more than 20 years. He’s never been infected with a tick-borne illness.

For defensive weapons, Mr. Telford recommends using a DEET based repellent, wearing long sleeves and long pants and treating a set of clothes, including socks and shoes, with permethrin. Light colored clothes will help make the diminutive nymphs more visible. “Spray the clothes with permethrin until they’re saturated then leave them in a cool dark place to dry,” he said. “Then you’re good to go for the rest of the summer. It’s perfectly safe. Permethrin is the active ingredient in delousing shampoos. It’s not a repellant, but it’s even better, because in three hours, any tick that touches you will be dead.” Mr. Telford added that permethrin is safe on humans and dogs, but not for cats.
A recently released two year study from the University of North Carolina  determined that outdoor workers using permethrin treated clothes had 80% fewer tick bites than those who didn’t.

Permethrin can also be used to make tick tubes — cardboard toilet paper tubes stuffed with permethrin saturate cotton balls. White-footed mice use the cotton to line their nests and any ticks that cozy up to them next winter will die. According to recent information from the American Entomological Society, deer tick larvae don’t have adverse affects on white-footed mice, but in fact they have a symbiotic relationship — the study found male mice with large tick loads were more likely to survive the winter. Breaking up this relationship with tick tubes can save countless cases of Lyme disease in the future. Mr. Telford recommends placing tick tubes every 15 feet along any areas that border on tick habitat, like scrub, woods or stone fences, and repeating the process in the fall.

Why Martha’s Vineyard?

The confluence of several factors, some of them man-made, make the Vineyard a hotspot for tick-borne illnesses. “Part of the reason ticks are so bountiful on the Island is the lack of extreme temperatures and lack of predators,” Mr Telford said. “In New England, we let pastures go to forest, which changed the fauna all to the tick’s advantage. We helped them because more people live in forest to be close to nature, and people are being lazy about leaf litter.”

Bearing out Mr. Telford’s point, last week, the Center for Vector-Borne Disease at the University of Rhode Island released a study that concluded, after examining 14 years of tick surveillance and corresponding weather data, that moisture, specifically in leaf litter, is a major factor in predicting deer tick population.

“If it’s a rainy and damp spring, it’s all the more reason to be vigilant about removing leaf litter and to spray the perimeter of your property, especially if you live, like many Islanders do, in a wooded area,” Mr. Telford said. “Spraying is not a bad word. The sprays are much more environmentally friendly than they were ten years ago. Pyrethroids aren’t harmful to humans. If you’re having grandkids or a wedding in June, you should seriously consider spraying your yard.”
Islanders take note — permethrin spraying on Martha’s Vineyard requires an applicator’s license.

Deer density

deer-with-ticks-1.jpgAnother reason the Island is teeming with ticks is the white-tailed deer population, the primary food source for adult ticks. “There’s no question that deer density has a direct correlation with tick-borne diseases,” Mr. Telford said. “And deer density on the Vineyard is among the highest in the state.”

Last August, at a presentation sponsored by the Martha’s Vineyard Boards of Health Island-Wide Tick Borne Illness Prevention Program (MVBOH), Thomas Millette, professor at Mount Holyoke College, gave the results of a deer density study conducted during the winter of 2012-2013, done by criss-crossing the Island with a thermal imaging camera. “Once we had the answers, I was shocked,” he said. “The Island has an average of over 50 deer per square mile.”

The Massachusetts Division of Fisheries and Wildlife preliminary deer harvest data for the 2013 season showed Island hunters took 713 deer, up significantly from the 2012 tally of 610 deer.

On Tuesday, Mr. Millette shared his preliminary findings from this winter’s study with The Times. It appears that neither hunters nor cars made a dent in the deer population.  “The number of deer we saw this past winter is virtually identical to last winter, within four or five deer,” he said.

Neither study Mr. Millette conducted included deer-rich Chappaquiddick because ground temperatures weren’t cold enough to give the contrast needed to confirm the presence of a warm-blooded deer.

Check please

Ultimately, daily tick checks from now until the end of summer are the best defense against Lyme disease and other tick-borne illnesses like babesiosis, which goes in tandem with Lyme about 10 percent of the time.
According to the New England Journal of Medicine, a single dose of doxycycline administered within 72 hours of a tick bite reduces the risk of Lyme disease by 87 percent.

“Halfway through the time of feeding is when the tick starts to spit infectious material into the host,” Mr. Telford said. “If you pull a nymphal deer tick off within 24 hours, there’s a very good chance you won’t get infected. An adult tick is easy to spot and it takes seven days to feed. Chances are pretty good you’ll find it before three days pass. And as the CDC has said, taking two tablets of doxycycline after recognizing a tick bite dramatically reduces chances of infection.”

Mr. Telford said a major asset the Vineyard has in the battle against Borrelia burgdorferi is the Martha’s Vineyard Boards of Health website and he urges all Islanders to visit it. “It’s one of the best websites in the country,” he said. “I’m delighted Mike Loberg is running it.”

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Dr. Stuart Harris stressed prevention as the first defense against tick borne diseases. — Photo by Nelson Sigelman

“I’ve taken tons of transfers from Martha’s Vineyard Hospital (MVH), but this is my first time on the Island,” Dr. Stuart Harris, chief of the wilderness medicine division and director of emergency medicine at Massachusetts General Hospital (MGH), said as he began his seminar on tick-borne diseases. Through the partnership between MGH and MVH, Dr. Harris has a longstanding working relationship with MVH emergency medicine director Dr. Jeffery Zack.

Dr. Harris was on the Island on Saturday to participate in the annual Martha’s Vineyard Hospital Health Fair. He talked about a wide range of tick-borne diseases – how to spot them, how to treat them, and most importantly, how to prevent them. He is well aware of the impact tick-borne disease has had on the Island.

Ticking clock

Although it still feels like winter, Islanders are already reporting ticks on their pets and on themselves. In a few weeks, ticks will be out en masse. Deer ticks, also known as black legged ticks, are the primary vectors for tick-borne illnesses.

“Spring is time for the nymphs,” Dr. Harris said. “This is when they do the most damage on the human population, in part because they are so hard to spot. Deer tick nymphs can be the size of a period on a page of text. They’ve evolved to block our sensation, they have an anesthetic in their saliva and they can attach and have a nice meal without us feeling it and brushing them off like we would a mosquito. It’s that same saliva that transmits disease from the tick to us.”

Dr. Harris estimated that about 1.4 to three percent of the human population in endemic areas contracts Lyme disease each year. Given that the Island is ground zero for Lyme disease, that statistic could be much higher on the Vineyard.

Not every tick carries Lyme, consequently not every tick bite leads to infection. Tick expert Dr. Sam Telford of Tufts University, said in an email to the Times, “The Lyme infection in nymphal deer ticks in coastal New England ranges from 10 per cent to 35 per cent, and for adult deer ticks, double that.”

Check please

The deciding factor in tick borne illness is how long the tick feeds on its human prey.  “Even if an infected tick bites you, if you catch it before 36 hours, the chance of becoming infected is negligible,” Dr. Harris said.

The majority of infections to humans occur between April and June, and frequent tick checks should be part of every Islander’s daily routine during this time. “At least once a day, do a tick check,” Dr. Harris said. “I can’t stress this one enough. Check yourself, check your kids, check your pets. And don’t just depend on your eyes. We tend to notice them with our fingertips, which is one of the most sensitive parts of the body.”

Dr. Harris recommended paying close attention to the armpits, the hair, behind ears and the crotch. He also advised using blunt-tipped forceps, not fingers, to remove a tick. “Grasp as close to the skin as possible, don’t pull too fast or too hard. If you leave the head, you can try to get it out with a needle.”

Know thine enemies

The telltale bull’s-eye rash that comes with Lyme disease infection shows up about 70 percent of the time, according to Dr. Harris. If Lyme disease goes treated, a host of more severe symptoms can develop, including facial palsy, heart damage, and debilitating arthritis. “If a pregnant woman finds a tick bite, I’d start a course of doxycycline immediately, as a preventative measure. Lyme transmitted to a fetus can be fatal.”

While Lyme disease is the most commonly reported tick-borne illness in the United States, there are a host of other tick-borne illnesses that work in concert with it.

Rocky Mountain spotted fever, while rare, is alive and well in our area and much more virulent than Lyme disease.

“Ironically, it’s found the least in the Rocky Mountain region,” Dr. Harris said. “About 80 percent of the time, Rocky Mountain spotted fever announces its arrival with a spotty red rash that usually starts on the hands and feet. Within hours, nausea and vomiting can lead to multi-system organ failure. If I misdiagnose Lyme, I can correct that; if I misdiagnose Rocky Mountain spotted fever, my patient can be dead the next day.” Dr. Harris said with proper diagnosis and heavy doses of doxycycline, a person can fully recover.

Ehrlichiosis, like Lyme disease, brings on intense, flu-like symptoms. It’s spread by the deer tick, but primarily it’s spread by the Lone Star tick.

“For some reason, it typically affects older men,” Dr. Harris said. “One in 10 people who are infected have Lyme as well. One to five people per hundred die from ehrlichiosis.”  

Although the Lone Star tick is endemic to the southern U.S., it has made its way north, and established populations on Cuttyhunk, Nashawena, and Prudence Island. A few specimens were found on the Island last year, but so far, no year-round populations have been found.

Babesiosis “lines the red blood cells like malaria,” Dr. Harris said. “Twenty percent of the time it is concurrent with Lyme.”

Babesiosis comes with a high fever that mysteriously comes and goes. “It seems to happen more often to people with long hair,” Dr. Harris said with a shrug. Untreated, babesiosis can lead to renal failure, anemia, and ascending paralysis. It’s the only tick-borne disease not cured by doxycycline.  

“With proper doses of Atovaquone, babesiosis is 100 percent treatable,” Dr. Harris said.

Really old Lyme

Because the Borrelia burgdorferi, the bacterium that causes Lyme disease, was discovered in 1982, many people assume Lyme disease is a recent phenomenon.  But Dr. Harris said that while our detection methods are recent, Lyme disease is not.

“Lyme disease has been around a lot longer than most people thought,” Dr. Harris said, showing a slide of Otzi, the well-preserved natural mummy found in 1991 in the Alps between Austria and Italy and who walked the earth around 3300 B.C.  “It turns out Otzi had Lyme too.”

Correction: An earlier version of this story incorrectly quoted Dr. Harris saying that one to three percent of ticks have Lyme disease. Dr. Harris said that one to three percent of humans in endemic areas contract Lyme disease.