Lyme disease in New Jersey outdoor workers: a statewide survey of seroprevalence and tick exposure.

To evaluate the spread of Lyme disease in New Jersey, we conducted a statewide cross-sectional study of Lyme disease seroprevalence in a high-risk occupational group of outdoor employees. Of the 689 employees who participated in the study, 39 (5.7 percent) were positive for antibody to B. burgdorferi, the causative agent of Lyme disease. Seroprevalence varied markedly by county; unexpectedly high seroprevalence rates were found in several northern counties (Sussex, Hudson, and Hunterdon). Furthermore, some southern counties (Atlantic, Cape May, and Ocean) with large tick populations (as measured by self-reported exposure to ticks) had low seroprevalence rates which were inversely correlated with self-reported preventive practices. These data suggest that lyme disease, as measured by seroprevalence of antibody to B. burgdorferi, may be spreading beyond the southern portion of the state where it had been previously well documented and that preventive behaviors may play an important role in minimizing the risk of the disease.