COVID-19 pandemic impact on blood donations and discards from screening tests for transfusion-transmitted infections in a Brazil Brazilian metropolitan area

The COVID-19 pandemic posed a worldwide challenge for blood services. We aimed to evaluate the impact of the COVID-19 pandemic on blood donations and blood discards resulting from screening tests for transfused-transmitted infections (TTIs) in a Brazilian metropolitan. Time-series cohort study including data of all blood donors from January 2018 to December 2021 at the Brasília Blood Center Foundation, Federal District, Brazil. The causal impact analysis was used to evaluate the impact of COVID-19 on blood donations, and a propensity score matching was used to evaluate the effect of the COVID-19 pandemic on the seroprevalence of TTIs. There were 205 965 blood donations during the study period. The blood donations significantly reduced soon after the onset of the COVID-19 pandemic in Brasilia, Brazil, in March 2020 until August 2020 (absolute effect per week: -2952; 95% CI: -4627 to -1355). However, from September 2020 to December 2021, blood donations had returned to the levels foreseen by the time-series model. Compared to the pre-COVID-19 period, the period between September 2020 and December 2021 was associated with a decrease of at least one reactive or indeterminate screening test for TTI (OR: 0.753, 95% CI: 0.665-0.854, p <0.001). There was a substantial decrease in blood donations soon after COVID-19 onset in Brazil. However, within a few months, the donation levels had returned to those projected by the model, possibly due to measures implemented by the blood centre for blood donations. The seroprevalence of TTIs decreased during the COVID-19 pandemic.