See if you agree with me that the following account reads like a detective novel:
In 1975, a cluster of more than 50 people, including children, contracted a mysterious disease. After much investigation, Dr. Willy Burgdorfer, “snagged” the wiggling culprit. It was a spirochete bacterium, code name: Borrelia burgdorferi.
The carrying agent was Ixodes dammini, the deer tick. Also implicated in the disease were white-footed mice and other small mammals, birds, dogs, deer, and humans. The cluster of cases had occurred in Lyme, Connecticut, and henceforth the sickness was called Lyme disease. While the original mystery was solved long ago, investigation of the tick and the disease continues.
You’ll probably be surprised to know that the deer tick is now known as the black-legged tick. Its scientific name has been changed from Ixodes dammini to Ixodes scapularis.
Its numbers have been steadily increasing since the 1960’s. Some people feel that a larger deer population may account for the increase in ticks.
Across the nation, cases of Lyme disease have been reported in all states except Alaska. Migrant birds may have helped spread the disease. Pennsylvania, New York, and the lower part of New England have the heaviest concentration of the illness. In PA, most of the cases occur in the most densely populated counties, Montgomery, Bucks, Delaware, and Philadelphia.
Ongoing research includes vaccine testing at two large pharmaceutical companies, better diagnostic testing, and improved antibiotic treatment. Other experimentation includes using pheromones to increase the effectiveness of insecticides.
The black-legged tick is much smaller than the more familiar American dog tick (Dermacentor variabilis). Ixodes scapularis has a black head and a brick red abdomen. The body color changes to gray after feeding. Ticks are not insects, but arthropods related to spiders and scorpions. Ticks are parasites that crawl (not jump!) onto warm-blooded animals from the tips of grasses and shrubs (not from trees). Tick habitat includes the forest, brushy areas, meadow, and even lawns and gardens. Not all black-legged ticks carry the spirochete that causes Lyme disease.
The life cycle comprises four stages that occur over a two year period. The tick only needs three meals to survive, one at each stage, except the egg stage.
Egg: Up to 3,000 eggs are laid in spring.
Larva: The larva has six legs rather than the usual eight. It is as tiny as the period at the end of this sentence, or a grain of sand. It is most active in late summer, but is not usually infected with the bacterium. Larval ticks are most likely to feed on mice. They molt into a nymph over the winter.
Nymph: The nymph is about the size of a poppy seed. It feeds on rodents and other hosts. It is most active in summer. After its meal, the tick drops into the leaf litter and molts into an adult in late summer.
Adult: Adult black-legged ticks are 2 mm in size, like a sesame seed. They feed mostly in the fall, after which eggs are laid that hatch into larvae in the spring.
Most bites are from nymphs that are more likely to go undetected and thus transmit disease. You won’t feel the bite, so remember to check the places that they like to attach: the back of the knees, groin, belt line, under the arms, and the back of the neck. Those found on the scalp have crawled there from the lower part of the body. If left undisturbed, they will feed for three to four days. That is about the same amount of time it takes for disease transmission.
To remove a tick, use a fine-tipped tweezer. Grab the tick as close to the skin as possible and pull it out, gently, but firmly. Try not to aggravate the tick by using a match, Vaseline, or nail polish remover because then it is more likely to inject you with the spirochete. Don’t worry if the head remains embedded. Mouthparts alone cannot transmit the disease. Wash the bite site and use alcohol or an antibiotic ointment. Save the tick in a jar of alcohol in case disease symptoms appear.
An early symptom that not all people get is a slowly expanding red rash. The rash begins as a small red spot that expands to a diameter of 1 to 18 inches. After several days, the center of the rash may clear partially. Other early symptoms are flu-like, such as fatigue, nausea, diarrhea, stiff neck, muscle and joint pain, headache, and fever. Later symptoms may include Bell’s palsy, joint problems (similar to arthritis), heart and nervous system complications. These symptoms usually don’t develop if the person is treated for the rash.
If you have the symptoms, a blood test will be performed at least six weeks after the bite for the detection of antibody. If symptoms continue though the test was negative, it is repeated. Even so, tests for Lyme disease are often inconclusive.
Lyme disease is treated with antibiotics, such as doxycycline, amoxicillin or cefuroxime. They are given by mouth or intravenously in severe cases. Even with those patients who are treated in the later stages, full recovery is possible.
As a naturalist, I’m not going to recommend that you stay out of the woods. Let's not let the threat of Lyme disease ruin our interest in nature! Ticks are part of the ecosystem and they’ve been here for eons. Instead, take some preventive measures like:
Wearing light-colored clothing so that ticks can be seen better
Tucking pant legs into boots or socks
Walking in the center of the trail, which we should do anyway to lessen our impact in the woods
Doing a “frecklecheck” when you come back inside
Being knowledgeable about disease symptoms and responding quickly if you notice any signs
Meanwhile, remember that real freckles don’t have squiggly little legs. Don’t be overcome by irrational fears. Enjoy your time in the out-of-doors!