D3202: Putting the puzzle pieces together: Understanding risk for human exposure to blacklegged ticks (Ixodes scapularis)

In the northeastern United States, blacklegged ticks (Ixodes scapularis Say, Acari: Ixodidae) transmit the causative agent of Lyme disease and several other pathogens to humans. To better understand tick bite risk, we examined 615 ticks submitted to the WCSU Tick Lab by Connecticut residents as part of several Lyme and other tickborne disease prevention studies. In this study, the scutal index was used to determine the duration of tick attachment. These findings were compared to a survey in which those submitting ticks were asked about their daily activities prior to tick detection. Of 166 blacklegged ticks found crawling on or attached to humans, 76% were likely encountered in the residential setting. Adult ticks were more likely to be detected within 0-24 hours than smaller nymphal stage ticks. The majority (88%) of nymphs were found after having already attached to the human body, whereas more than one-third of adult ticks were detected while crawling. The primary activities associated with tick exposure were yardwork, gardening, and playing. Our findings reinforce previous studies indicating high risk for backyard tick exposure in Connecticut, and further emphasize the need to improve residential preventative behaviors, particularly for reducing human encounters with nymphal stage I. scapularis.