Passive Tick Surveillance for Ixodes scapularis and the Incidence of Lyme Disease in Connecticut

Lyme disease is a tick-borne disease, transmitted to humans via the bite of an Ixodes scapularis tick infected with the spirochetal bacterium Borrelia burgdorferi. This disease is endemic in Connecticut and has been increasing in prevalence throughout New England for the past 30 years. Data collected from I. scapularis ticks submitted by the public to the Connecticut Agricultural Experiment Station and the Connecticut Veterinary Medical Diagnostic Laboratory for B. burgdorferi testing from 2002 to 2012 were compared with Lyme disease case data from the Connecticut Department of Public Health to determine the capacity at which passive tick surveillance can be used to assess the risk of acquiring Lyme disease. The cumulative number of passively submitted ticks was moderately correlated with the number of reported Lyme disease cases among all Connecticut towns (r =0.488, p\u3e0.0001, n=169 towns). Passive tick submissions and Lyme disease cases were also correlated using data within the same surveillance year as well as the following surveillance year (r=0.473, p\u3e0.0001 and r=0.250, p\u3e0.001, respectively). The results of this project suggest that passive tick surveillance, using ticks submitted by the public for B. burgdorferi testing, may be used to evaluate the spatial and temporal impacts on Lyme disease incidence in Connecticut. However, the results of this study further imply that passive tick surveillance was more strongly correlated to the temporal measures examined in comparison to the spatial predictors examined. Consequently, passive tick surveillance may not be a reliable method for evaluating the spatial aspects of Connecticut’s Lyme disease incidence, but it may be a better predictor of Lyme disease incidence from year to year