Occurrence of erythema chronicum migrans and Lyme disease among children in two noncontiguous Connecticut counties.

In May-November 1977 erythema chronicum migrans of Lyme arthritis occurred in at least 12 children in New London County, Connecticut, east of the original 3-town epidemic focus. The attack rate (0.15 cases per 1,000 persons under 18) was considerably lower than within the focus itself but similar to the rate in towns west of the focus. No cases were identified in Litchfield County in northwest Connecticut. Observed rates of Lyme disease varied markedly within Connecticut in 1977.