Potential for exposure to tick bites in recreational parks in a Lyme disease endemic area.

Eight recreational parks located in a Lyme disease endemic area of southern New York State were surveyed for the presence of ticks during the summer of 1985 by drag sampling. Ixodes dammini, the primary vector of Lyme disease in the northeast, was found in all but one park and accounted for 580 (91.8 per cent) of the 632 ticks collected. Of these, 18 per cent were larvae, 80 per cent were nymphs, and 2 per cent were adults. An I. dammini encounter distance, defined as the mean number of meters traveled before encountering a nymphal or adult I. dammini on a drag cloth, ranged from 36 m in high-risk parks, to infinity (no tick encounters). Generally, areas of high use presented higher encounter distances (lower risk) than those of the entire park. Two of the three parks with the highest annual attendance also had the highest I. dammini population indices as projected from our sampling regimen. These results indicate that recreational parks in Lyme disease endemic areas represent a substantial human risk for tick bites and Lyme disease.