The Carlisle Mosquito Online

Friday, May 18, 2007


It's tick time again

Approximate sizes of the deer tick at different stages of the life cycle.
Long days, beautiful weather, sports, gardening and yard work all draw people closer to nature at this time of year. Here in Carlisle, that nature includes deer ticks, increasing numbers of which carry the bacterium, borrelia burgdorfi, that will infect humans and pets with Lyme disease in the coming months.

The number of Carlisle residents treated for Lyme disease continues to grow. Lyme disease can present an array of symptoms, and townspeople who have written or spoken with the Mosquito over the years have experienced the gamut from simple rashes, to headaches and 104°F fevers, to painful arthritis, and both temporary and permanent neurological complications.

Often, but not always, a rash will develop at the site of a deer-tick bite, from three days to a month after the bite. Starting with a red spot the rash can spread into a "bulls-eye" shape. Flu-like symptoms are common. The initial symptoms may clear up by themselves, or the rash may reappear in other locations, away from the site of the bite. Without antibiotic treatment, the disease can become chronic, leading to more serious problems. According to the Massachusetts Department of Public Health (DPH), of those who are not treated, almost two-thirds later develop arthritis in the knees, elbow or wrist, and one or two out of ten untreated people will later develop problems with their central nervous system, such as meningitis, facial (Bell's) palsy, pain or weakness in their arms or legs. Less frequently, Lyme disease can affect the heart.


Deer ticks are found on plants near the ground in fields or woods, waiting to hitch a ride with a person or animal that brushes by the plants. The youngest, dot-sized ticks pick up the disease when they bite infected animals. According to the DPH, humans are most likely to be infected by older ticks. It takes a while for the bacteria to be transferred to the new host after a tick begins to bite, and therefore removing the tick within the first 24 hours will greatly reduce the chance of infection.


Check skin for ticks daily and after any outing in the brush or woods. This is especially important now through August when Lyme infection is most common. Light-colored clothing helps make it easier to spot ticks. When it is too hot to wear long sleeves and long pants, insecticides containing DEET can be used to repel ticks.

Further reading

For more information, visit the Board of Health on the web at:, or the web site: Also, see the following articles in the Mosquito on-line archive: "Know the basics of Lyme disease prevention," by Dr. Claudia Talland, May 16, 2003, and "Carlisle residents tell their tales of Lyme disease," by Marilyn Harte, September 2, 2005.

2007 The Carlisle Mosquito