Abstract
Background
Human babesiosis is a mild-to-severe parasitic infection that poses health concerns especially in older and other at-risk populations. The study objective was to assess babesiosis occurrence among the U.S. Medicare beneficiaries, ages 65 and older, during 2006-2017.
Methods
Our retrospective claims-based study utilized Medicare databases. Babesiosis cases were identified using recorded diagnosis codes. The study estimated rates (per 100,000 beneficiary-years) overall, by year, diagnosis month, demographics, state and county of residence.
Results
Nationwide, 19,469 beneficiaries had babesiosis recorded, a rate of 6 per 100,000 person-years, ranging from 4 in 2006 to 9 in 2017 (p<0.05). The highest babesiosis rates were in: Massachusetts (62), Rhode Island (61), Connecticut (51), New York (30), and New Jersey (19). The highest rates by county were in: Nantucket, MA (1,089); Dukes, MA (236); Barnstable, MA (213); and Dutchess, NY (205). Increasing rates, from 2006 through 2017 (p<0.05), were identified in multiple states, including states previously considered non-endemic. New Hampshire, Maine, Vermont, Pennsylvania, and Delaware saw rates increase by several times.
Conclusion
Our 12-year study shows substantially increasing babesiosis diagnosis trends, with highest rates in well-established endemic states. It also suggests expansion of babesiosis infections in other states and highlights the utility of real-world evidence.
Babesiosis Occurrence among the U.S. Medicare Beneficiaries Ages 65 and Older, During 2006-2017: Overall, and by State and County of Residence