1720. Regional Differences in Trends of Hospitalizations Associated With Tick-Borne Diseases in the United States, 2009–2014

BACKGROUND: Tick-borne diseases are increasing in incidence in the United States; however, limited data exist on regional trends of associated hospitalizations. Using a nationally distributed dataset of US hospital-based medical records, we aimed to assess trends in incidence of hospitalizations from tick-borne disease by geographic region. METHODS: Data were examined from 156 US hospitals from 2009 to 2014 to identify hospitalizations with tick-borne disease. Cases were described and Poisson regression used to estimate the annual percent change (APC) and associated 95% confidence intervals (CI) in incidence by region over time. RESULTS: Overall, 2,543 hospitalized patients with tick-borne disease were identified (average annual incidence = 28.4 cases/100,000 hospitalized persons), including 1,613 (63%) with Lyme disease, 379 (15%) tick-borne fever, 293 (12%) ehrlichiosis, 93 (4%) babesiosis, 43 (2%) rickettsiosis, and 122 (4%) multiple tick-related diagnoses. Tick-borne diseases varied significantly by region, with Lyme disease more frequent in those residing in the Northeast (68%) than the South (57%) or West (42%) and tick-borne fever more common in the West (28%) vs. the South (18%), Midwest (14%), and Northeast (13%) (P < 0.0001). Significant increases in tick-borne disease hospitalizations were identified across nearly all US regions, ranging from 15% per year in the South (95% CI=8–24%) to 45% per year in the West (34–58%), with the exception of the Northeast, where incidence declined by 6% per year (0.04–11%). Lyme disease hospitalizations showed similar trends, with the greatest increase in the South (APC = 53%, 95% CI = 33–76%) and a decrease in the Northeast (APC = 13%; 3%–23%). Hospitalizations with tick-borne fever increased in the Midwest (APC = 49%; 8–206%) and Northeast (APC = 18%; 4–34%); with ehrlichiosisincreased in the West (APC = 231%; 75–306%); and with babesiosis increased in the South (APC = 50%; 12–201%) and the Midwest (APC = 21%; 5–39%). CONCLUSION: Incidence of hospitalizations from tick-borne disease is increasing throughout much of the nation, except in the Northeast where decreases in Lyme disease were observed. While hospitalizations with tick-borne diseases remain rare, the increases noted are substantial and may reflect rising incidence of these diseases within the represented states. [Image: see text] DISCLOSURES: All authors: No reported disclosures.