Lyme disease is expanding geographically in the US. Johns Hopkins researchers utilized Google Health Trends data to analyze internet Lyme disease searches to identify geographic patterns over time to better identify Lyme disease geographic risk. This approach was shown to be an effective tool that could complement traditional disease surveillance (case reports, lab test results, insurance claims data, electronic health records) to help inform the public and health care providers of high incidence, underreported, and emerging regions that form the leading-edge of disease expansion.

The geographic footprint of Lyme disease is expanding in the United States, which calls for novel methods to identify emerging endemic areas. The ubiquity of internet use coupled with the dominance of Google’s search engine makes Google user search data a compelling data source for epidemiological research. We analyzed internet search rates for Lyme disease-related queries at the designated market area (DMA) level (n = 206) for the 2011–2019 and 2020–2021 (COVID-19 pandemic) periods. Mapping DMA-level changes in “Lyme disease” search rates revealed an expanding area of higher rates occurring along the edges of the northeastern focus of Lyme disease. Bivariate maps comparing search rates and CDC-reported incidence rates also showed a stronger than expected signal from Google Health Trends in some high-risk adjacent states such as Michigan, North Carolina, and Ohio, which may be further indication of a geographic leading edge of Lyme disease that is not fully apparent from routine surveillance. Searches for “Lyme disease” were a significant predictor of CDC-reported disease incidence. Google Health Trends data may help track the expansion of Lyme disease and inform the public and health care providers about emerging risks in their areas.