Risk factors for human immunodeficiency virus infection among blood donors in Sao Paulo, Brazil, and their relevance to current donor deferral criteria

BACKGROUND: The objective of this study was to investigate risk factors of human immunodeficiency virus (HIV)‐seropositive blood donors in Brazil and to determine if current donor deferral criteria are appropriate. STUDY DESIGN AND METHODS: Demographic and behavioral data among cases with confirmed HIV seropositivity (n = 272) were compared with those who had a false‐positive serology (n = 468) between January 1999 and December 2003 in a case‐control analysis with logistic regression. RESULTS: Risk factors that should have resulted in predonation deferral were reported by 48.9 percent of HIV‐positive and 9.4 percent of false‐positive donors. In multivariate analysis, male cases were significantly more likely to report male‐male sex (adjusted odds ratio [AOR], 26.2; 95% confidence interval [CI], 7.8‐87.4), a previous sexually transmitted disease diagnosis (AOR, 3.2; 95% CI, 1.5‐6.9), exchanging money for sex (AOR, 2.1; 95% CI, 1.0‐4.2), and at least two partners in the past 12 months (AOR, 2.3; 95% CI, 1.4‐3.6). HIV‐positive male donors were also more likely to be reactive for the presence of hepatitis C virus antibody (AOR, 4.0; 95% CI, 1.3‐12.0) and hepatitis B virus core antibody (AOR, 3.8; 95% CI, 1.9‐7.7). Female cases were more likely to report an intravenous drug user partner (AOR, 12.4; 95% CI, 1.3‐120.2), a sexual partner with multiple sex partners or who had a history of sex with a sex worker (AOR, 13.0; 95% CI, 2.7‐63.2), and at least two partners in the past 12 months (AOR, 2.2; 95% CI, 1.0‐5.3). CONCLUSION: A substantial number of HIV‐infected donors reported a risk factor that could have been identified in the predonation screening. Male‐male sexual behavior was still the strongest determinant of HIV status in the studied population.