Seroprevalence and Risk Factors of STIs among Rejected Blood Donors at the National Blood Transfusion Service in Angola

Sexually transmitted infections (STIs) are a global health concern. Blood donation centres employ comprehensive screening measures to identify donors with STIs, such as HIV, HBV, HCV, and syphilis, which can also transmitted through blood transfusions. Herein, we investigated the seroprevalence of STIs and demographic determinants related to multiple infections among rejected blood donors at the National Blood Transfusion Service (NBTS) in Angola. This was a cross-sectional study conducted with 1885 rejected blood donors serologically screened for anti-HBsAg, anti-HCV, anti-HIV, and anti-TP during pre-donation screening at the NBTS, located in Luanda, the capital city of Angola, between March 2022 to July 2023. Overall, HIV (11.2%), HBsAg (71.7%), HCV (9.30%), and Syphilis (8.80%) were detected. The multiple infection rate was 2.30%. HIV and syphilis were associated with age (p < 0.05). HBV was related to age, areas of residence, and occupation (p < 0.05). HCV was related to areas of residence and educational level (p < 0.05). No relationship was observed between demographic characteristics with multiple infections (p > 0.05). Individuals aged over 40 years (OR: 2.48, p = 0.393), males (OR: 1.33, p = 0.639), non-urbanized regions (OR: 1.18, p = 0.594), low educational level (OR: 3.46, p = 0.222), and employed (OR: 1.34, p = 0.423), were more likely to have multiple infections. Our results demonstrate a high rate of circulation of STIs among blood donation candidates in Luanda. HBV was the main reason for the rejection of candidates. However, nucleic acid-based screening techniques should be considered to ensure better quality screening for occult infections in blood donor candidates.