Blood donor deferral in Minas Gerais State, Brazil: blood centers as sentinels of urban population health

BACKGROUND: Shortage of safe blood donors is frequent and it is important to understand the causes of deferral of potential donors, who reside mainly in urban areas, to improve recruitment campaigns aiming at the quality/availability of donors.
STUDY DESIGN AND METHODS: In Minas Gerais State, Brazil, Hemominas Foundation collects, analyzes, and distributes more than 90 percent of blood. Blood is collected in 19 centers in cities. In 2006, data from 335,109 attempts to donate were analyzed.
RESULTS: Seventy-seven percent of donor candidates were less than 40 years old, with 57.1 percent nonwhite and 66 percent male. A total of 21.6 percent were deferred at the interview. Women were more clinically deferred than men (25.5% vs. 19.6%). In larger cities, the proportion of first-time donors (FTs) was higher (67.8%). The main causes of permanent deferral among FTs were neurologic diseases (37.5%), chronic hypertension (22.2%), and endocrinologic diseases (9.9%). The main causes of temporary clinical deferral in this group were risky behavior for sexually transmitted diseases (32.6%), anemia (8.5%), and hypertension (6%). The main causes of permanent deferral in repeat donors (RTs) were chronic hypertension (31.6%) and neurologic diseases (22.1%); for temporary deferral it was anemia (22.6%). A total of 2.9% of the collected blood bags were discarded due to reactive tests (FTs = 34.82/1000; RTs = 3.51/1000).
CONCLUSION: A deferral study in blood donor candidates may shed light on regional diversity, highlighting how social inequalities and health status of the general population may affect the blood supply. Risk factors and marker rates derived from the donor pool may be useful to gain insights regarding public health issues.