Factors that Affect the Incidence of Babesia and Blood Donor Testing in Select States: A Regression Analysis

Aims: Babesiosis is a serious health concern that has resulted in fatalities and more than two hundred cases of transfusiontransmitted Babesiosis (TTB) in the United States. A study was conducted to identify climate factors that affect the number of cases of Babesia, and in addition pinpoint factors that may have impacted required testing on blood donors in select states. Methods: Logistic regression was performed using state as the dependent variable, and babesia cases and deaths as predictor variables. Multiple regression was performed using babesia cases as the dependent variable and temperature and precipitation as predictor variables. Cases of Babesia by state was accessed from the CDC for the years 2011-2020. Monthly climate data was accessed from the Northeast Regional Climate Center for the same timeframe. The number of deaths from Babesia was retrieved from state health departments. Statistical significance was set at P<.05. Results: Logistic regression revealed that the number of deaths from Babesia was a statistically significant factor in assessing what factors effected required donor testing (P<.05). Multiple regression revealed that temperature and precipitation had a significant effect (P<.05) on the number of cases of Babesia from 2011 to 2020. Conclusion: These findings add to the body of knowledge regarding Babesia transmission characteristics and factors prompting changes to donor testing across multiple states. Babesia microti is the most common transfusion transmitted parasite prompting continued surveillance of variables affecting transmission and evaluation of testing requirements.