The city mouse and the country mouse have even more in common than meets the eye — the tick that carries Lyme disease. Usually associated with deer, the blacklegged tick, known as Ixodes scapularis in the Northeastern United States, is carried by Whitetails that are infiltrating the urban landscape in record numbers.
Deer, however, may be getting a bad rap. They do spread the blacklegged tick, but it’s the white-footed mouse, in fact, that is responsible for infecting over 90 percent of these tiny ecoparasites with Lyme disease.
How Lyme is Spreading to the City
According to the CDC, documented cases of Lyme have increased three-fold since the 1990’s, and undocumented infections may be as high as ten times that. What’s to blame?
Researchers the Cary Institute point to many factors and have studied both temperature and the availability of food for deer, but found no significant correlation. What they did find is that a surge in the population of mice in any given area is strongly predictive of an increase in Lyme disease.
Why is this happening? Scientists aren’t sure, but what they’ve noticed is that in areas where Lyme disease is spreading rapidly — the northeast, mid-Atlantic and north-central United States — the habitat for both deer and mice is expanding. Contrary to popular belief that human encroachment into wooded areas is always to blame, investigators say that a renewed interest in bringing some of nature to the city in the form of parks, preserves and reclaimed agricultural areas is bringing black-legged ticks right to the human buffet.
Tick Bite Prevention
Until urban and public health planners develop a comprehensive plan for control, tick bite prevention is the most effective way to avoid Lyme disease. The CDC recommends the following measures.
- Avoid walking in tall grass and leaf litter both at home and during outdoor excursions.
- Bring some sun into the yard. The nymph form of the blacklegged tick that spreads Lyme disease needs humidity to thrive. Removing high grass, moisture-retaining shrubs and piles of wet lawn debris eliminate tick habitat and naturally reduce exposure potential.
- Apply pesticide or tick repellant in high-risk areas of the yard. Keep pets treated for ticks and consider a fence to keep deer out.
- Cover up. Wear long pants and pull socks over the hem. Light-colored long-sleeve shirts provide bite protection as well as a surface that make tiny Ixodes scapularis nymphs more visible. A wide-brimmed hat completes the ensemble.
- Treat clothing and footwear products containing 0.5% permethrin.
- Visit the Environmental Protection Agency website for a list of approved insect repellants as well as guidance for effective use.
- Check your body after being outdoors. Carefully inspect around the hairline and in moist skin folds in the groin, around the waist, under the arms, and behind the knees.
What to Do After a Tick Bite
If you find a tick on your body, remove it. Use fine-tipped tweezers to grasp the tick close to the skin and pull with gentle, even pressure. Cleanse the area thoroughly with soap and water.
Evidence suggests that ticks need to be embedded in the skin for at least 24 hours to impart Lyme disease. However, this idea is evolving, and all tick bites should be carefully monitored for a least a few weeks. Since only a third of those with Lyme disease recall being bitten by a tick, see a doctor promptly for these symptoms.
Early Symptoms of Lyme Disease
- A red rash surrounding the bite. Such a rash is present in only 30-80 percent of cases and may not cause noticeable symptoms like pain or itching.
- Flu-like symptoms including fever, chills, muscle aches and swollen glands.
Late Symptoms of Lyme Disease
- Neurological symptoms including Bell’s Palsy, a partial paralysis of the facial muscles
- Joint pain and inflammation
- Changes in heart rate and rhythm
- Profound fatigue with difficulty concentrating
Testing and Treatment for Lyme Disease
In addition to a health history and symptom evaluation, one of several simple blood tests can diagnose Lyme disease.
Treatment of early symptoms is an average of three weeks of a common antibiotic such as doxycycline or amoxicillin. In the late stages, intravenous antibiotics and additional supportive care may be needed. With appropriate treatment, most people recover quickly and thoroughly, however, in a few cases, symptoms may persist.
Tick bite prevention is the best medicine in the fight against Lyme disease, but if suspicious symptoms arise, seeing a doctor promptly ensures the best chance of a full and uneventful recovery.