Peridomestic Lyme disease prevention: results of a population-based case-control study

Peridomestic Lyme disease-prevention initiatives promote personal protection, landscape modification, and chemical control.

A 32-month prospective age- and neighborhood-matched case-control study was conducted in Connecticut to evaluate the effects of peridomestic prevention measures on risk of Lyme disease.

The study was conducted in 24 disease-endemic Connecticut communities from 2005 to 2007. Subjects were interviewed by telephone using a questionnaire designed to elicit disease-prevention measures during the month prior to the case onset of erythema migrans. Data were analyzed in 2008 by conditional logistic regression. Potential confounders, such as occupational/recreational exposures, were examined.

Between April 2005 and November 2007, interviews were conducted with 364 participants with Lyme disease, and 349 (96%) were matched with a suitable control. Checking for ticks within 36 hours of spending time in the yard at home was protective against Lyme disease (OR=0.55; 95% CI=0.32, 0.94). Bathing within 2 hours after spending time in the yard was also protective (OR=0.42; 95% CI=0.23, 0.78). Fencing of any type or height in the yard, whether it was contiguous or not, was protective (OR=0.54; 95% CI=0.33, 0.90). No other landscape modifications or features were significantly protective against Lyme disease.

The results of this study suggest that practical activities such as checking for ticks and bathing after spending time in the yard may reduce the risk of Lyme disease in regions where peridomestic risk is high. Fencing did appear to protect against infection, but the mechanism of its protection is unclear.