Risk Factors for Viral Coinfections in Blood Donors in Bahia, Brazil

Human Immunodeficiency Virus (HIV), Human T Lymphotropic Virus (HTLV), Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) coinfection may lead to disease progression or worsen its clinical presentation. Viral coinfections screening during blood donation is critical. To identify risk factors for coinfection among blood donors, we assessed the blood donations at the Fundação de Hematologia e Hemoterapia da Bahia, from 2008 to 2017. We compared serological/molecular evidence of single infection versus two or more viral blood-borne infections-BBI). A multivariable logistic regression model was performed to evaluate independent associations between characteristics of donors with single infection and multiple infection using "non-infection" category as reference. Among 777,446 collected blood donations, 27 358 (3.5%) were reactive, most (n = 26 677, 97.6%) for a single infection and 681 (2.4%) for coinfection. The most frequent coinfections were HBV-HIV (30.6%), HBV-HCV (30.4%), and HBV-HTLV (24.4%). Male sex, lower education, being single, and being a first-time donor were independently associated with both single and coinfections. Nevertheless, the adjusted odds for risk factors of coinfections were much higher than those for single infection. Donors with single and coinfection for BBI shared identical risks, but they were significantly higher for coinfection. Preventive strategies addressing the identified risks can decrease transmission of viral BBI by blood transfusion.