Nationwide Seroprevalence Study of Hepatitis B and Hepatitis C Viruses Among Blood Donors in Paraguay

The true burden of Hepatitis B virus (HBV) and Hepatitis C virus (HCV) in Paraguay remains poorly defined, hindering effective public health planning toward the WHO's 2030 elimination goal. This cross-sectional study aimed to establish a comprehensive, nationally representative epidemiological baseline among blood donors.We prospectively analyzed 85,811 blood donor samples. Screening involved chemiluminescent immunoassays for anti-HBc, HBsAg, and anti-HCV, followed by confirmatory Nucleic Acid Amplification Testing (NAT) for HBV-DNA and HCV-RNA.Overall seroprevalence was low: 1.35% for anti-HBc, 0.086% for HBsAg, and 0.267% for anti-HCV. However, significant regional variations were noted, with anti-HBc prevalence ranging from 0.70% to 3.86% (p < 0.001). Anti-HBc also increased with age (0.27% in < 20 years to 3.10% in > 50 years). Critically, no HBV markers were detected in donors born after the national 2003 vaccination program. Only 1 of 229 anti-HCV reactive samples was HCV-RNA positive.While low overall seroprevalence confirms blood safety standards, pronounced regional disparities require targeted public health interventions focused on specific epidemiological hotspots. The absence of HBV markers in the post-vaccination cohort provides strong evidence of the national immunization program's success, offering an invaluable baseline for future elimination strategies.