Tick-borne diseases are commonly reported in the United States, but frequency of tick bites and care-seeking behaviors following tick bites are poorly understood. We used nationally representative survey data to describe the frequency of tick bites among people living in the United States and how often, where, and why care-seeking associated with tick bites occurs. We found that over 31 million people (nearly 1 in 10) living in the United States might experience a tick bite each year and highlight regional trends in associated care-seeking behaviors. These findings emphasize the need for effective tick bite prevention education and regionally tailored healthcare provider recommendations for management of tick-borne diseases.

BACKGROUND: Commercial insurance claims data are a stable and consistent source of information on Lyme disease diagnoses in the United States and can contribute to our understanding of overall disease burden and the tracking of epidemiological trends. Algorithms consisting of diagnosis codes and antimicrobial treatment information have been used to identify Lyme disease diagnoses in claims data, but there might be opportunity to improve their accuracy. METHODS: We developed three modified versions of our existing claims-based Lyme disease algorithm; each reflected refined criteria regarding antimicrobials prescribed and/or maximum days between diagnosis code and qualifying prescription claim. We applied each to a large national commercial claims database to identify Lyme disease diagnoses during 2016-2019. We then compared characteristics of Lyme disease diagnoses identified by each of the modified algorithms to those identified by our original algorithm to assess differences from expected trends in demographics, seasonality, and geography. RESULTS: Observed differences in characteristics of patients with diagnoses identified by the three modified algorithms and our original algorithm were minimal, and differences in age and sex, in particular, were small enough that they could have been due to chance. However, one modified algorithm resulted in proportionally more diagnoses in men, during peak summer months, and in high-incidence jurisdictions, more closely reflecting epidemiological trends documented through public health surveillance. This algorithm limited treatment to only first-line recommended antimicrobials and shortened the timeframe between a Lyme disease diagnosis code and qualifying prescription claim. CONCLUSIONS: As compared to our original algorithm, a modified algorithm that limits the antimicrobials prescribed and shortens the timeframe between a diagnosis code and a qualifying prescription claim might more accurately identify Lyme disease diagnoses when utilizing insurance claims data for supplementary, routine identification and monitoring of Lyme disease diagnoses.

AIMS AND METHODS: In the United States, blacklegged Ixodes spp. ticks are the primary vector of Lyme disease. Minnesota is among the states with the highest reported incidence of Lyme disease, having an average of 1857 cases reported annually during 2011-2019. In contrast to the Northeast and mid-Atlantic United States where exposure to ticks predominately occurs around the home, the circumstances regarding risk for exposure to blacklegged ticks in Minnesota are not well understood, and risk is thought to be highest in rural areas where people often participate in recreational activities (e.g. hiking, visiting cabins). We analysed enhanced surveillance data collected by the Minnesota Department of Health during 2011-2019 to describe epidemiologic and tick exposure characteristics among people with reported Lyme disease. RESULTS: We found that younger age, male gender, residence in a county with lower Lyme disease risk, residence in the Minneapolis-St. Paul metropolitan area, and an illness onset date later in the year were independently associated with higher odds of reporting tick exposures away from the home. We also describe the range of activities associated with tick exposure away from the home, including both recreational and occupational activities. CONCLUSIONS: These findings refine our understanding of Lyme disease risk in Minnesota and highlight the need for heterogeneous public health prevention messaging, including an increased focus on peridomestic prevention measures among older individuals living in high-risk rural areas and recreational and occupational prevention measures among younger individuals living in the Minneapolis-St. Paul metropolitan area.