Abstract
Observed differences in tick characteristics between the 2 data sources may represent real differences between tick populations and human encounters. Some differences may be explained by observation, reporting, and sampling biases. Increased observations of ticks at the beginning of the season indicate potential utility of enhanced human Lyme disease surveillance at that time. These One Health findings signal an opportunity for early identification of high tick-borne disease years through integrated active and passive tick surveillance that informs the conduct of human disease surveillance.