FRIDAY, Dec. 16 (HealthDay News) -- The prevalence of babesiosis among elderly Medicare beneficiaries in the United States increased from 2006 to 2008, with significant variations across race, gender, age, and state of diagnosis, according to a study published online Dec. 14 in the U.S. Centers for Disease Control and Prevention's Emerging Infectious Diseases.
Mikhail Menis, from the U.S. Food and Drug Administration in Rockville, Md., and colleagues assessed annual rates of babesiosis among elderly Medicare beneficiaries (aged 65 years and older) in the United States during 2006 to 2008, using Medicare & Medicaid Services administrative databases. The estimated rates were stratified by year, age, sex, race, state of residence, and month of diagnosis.
The investigators found that 985, 851, and 1,223 babesiosis cases were recorded in 2006, 2007, and 2008, respectively, yielding corresponding annual rates of 3.6, 3.2, and 4.7 per 100,000 beneficiaries. Annual babesiosis rates for those years were significantly higher among white elderly (4.0, 3.6, and 5.2, respectively) compared to non-white elderly beneficiaries (0.6, 0.9, and 1.4, respectively). Significantly higher rates were observed for men than women, and for young elderly women (65 to 84 years) than older elderly women (≥85 years). July and August saw the highest number of cases, with 74.4 percent of diagnoses occurring in May through October. The top 10 states and District of Columbia accounted for 84.7, 83.3, and 83.7 percent of cases in 2006, 2007, and 2008, respectively. The highest rates were seen in Connecticut, Rhode Island, New York, and Massachusetts.
"Overall, our three-year study suggests that there were more cases of babesiosis in 2008 compared with previous years," the authors write.