Take Precautions Against Lyme Disease
Recent reports have suggested that tick populations may be particularly high this year, leading to an increased risk of Lyme disease in the Northeast and Mid-Atlantic regions of the U.S.
Although it is unclear whether the number of ticks actually is higher this year — and if so, why — it nonetheless always is a good idea to take precautions to avoid ticks and the diseases they can transmit, according to entomologists in Penn State’s College of Agricultural Sciences.
“Some people believe a perceived increase in ticks can be blamed on a mild winter, an early spring, certain precipitation patterns or a large crop of acorns that leads to an overabundance of mice that host ticks,” said Steven Jacobs, senior extension associate in entomology. “However, some of these theories have little scientific basis, and most scientists agree that nature is too complex to attribute a rise or fall in the tick population to any one factor.”
Joyce Sakamoto, a research associate in entomology who studies tick biology, said the impression that tick populations are higher this year may have come from the fact that ticks emerged earlier than usual from winter dormancy.
“The number of ticks I’m finding…is comparable to previous years,” she said. “But I did start seeing active adult ticks earlier than usual — in February — both this year and last year.”
Sakamoto noted that 40-60 percent of the ticks she tests carry the Lyme disease pathogen, though that doesn’t necessarily mean all of them are capable of transmitting the illness, she explained.
Whether there has been a spike in ticks this year or not, there is no question about the long-term trend. “Fifteen or 20 years ago, the ticks that carry Lyme disease were rare in many [areas], but unfortunately that has changed,” Jacobs said.
Sakamoto added that public awareness of ticks also has increased with growth and development. “We keep expanding into habitats where ticks are found,” she said. “And as that continues, we need to change our behavior to avoid them.”
Lyme disease symptoms
Even though ticks can transmit a variety of pathogens, it is no secret why Lyme disease gets the most attention. Lyme disease can cause a variety of symptoms, including a bull’s-eye-like rash, fever, stiff neck, muscle aches and headaches. Left untreated, victims can suffer facial palsy, arthritis and even paralysis. It normally is treated with antibiotics, but if not caught early, recovery can be slow and difficult.
The primary vector of the Lyme disease bacterium is the blacklegged tick — often called the “deer tick.” Adult ticks can be active from fall through spring if temperatures remain above 28 Fahrenheit. Ticks in the nymphal (immature) stages are active in May, June and July.
Nymphs will attach to mice, chipmunks, birds and other small animals. Adults typically attach to white-tailed deer or other large mammals. While awaiting a suitable host, the ticks usually are found on leaf litter or low branches in brushy, wooded areas.
“The larval and nymphal stages of the tick are no bigger than a pinhead,” Jacobs said. “Adult ticks are slightly larger. Research in the eastern United States has shown that ticks most often transmit Lyme disease to humans during the nymphal stages. That’s probably because nymphs are so small they go unnoticed on a person’s body, meaning they typically have more time to feed and transmit the infection before they are detected.”
Avoiding Lyme disease
Jacobs recommends avoiding tick-infested areas such as woods with a high deer population, especially in May, June and July when the nymphs are active.
The D.C. Department of Health urges people to take the following precautions:
- Use insect repellents containing DEET.
- Wear light colored clothing that covers legs and arms so that ticks may be more easily seen and removed.
- Tuck pants into socks and/or boots.
- Tuck shirt into pants.
- Do a daily tick check; examine all parts of the body daily for the presence of ticks.
- Remove ticks promptly by using gentle, steady traction with tweezers applied close to the skin to avoid leaving parts in the skin. Following removal, clean the bite area with soap and water.
“Be especially vigilant near perimeter areas of tick habitat, such as the edge of woods and along paths and trails,” Sakamoto said. “Ticks can sense carbon dioxide, heat, vibration and chemical cues left by other ticks, and there’s evidence that they may be more concentrated in areas where they’re more likely to encounter potential hosts.”
Also, know the signs of Lyme disease and see your doctor if symptoms develop, Jacobs said. “If a tick is found attached to a person, it should be removed by carefully grasping the tick with tweezers as close to the skin as possible and pulling straight back with a slow, steady force. Avoid crushing the tick’s body.”
He said a tick can be identified by placing it in a small vial filled with rubbing alcohol and taking it to the health department or a county agricultural extension office.
To learn more about blacklegged ticks and Lyme disease, visit the CDC’s website.
Chuck Gill contributed to this report.