Getera Isack Nyangi^1,, Godfrey Nyandidi², Victoria Avelin Marunda³

Human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) remain major global public health challenges, contributing substantially to chronic liver disease and premature mortality. Married couples represent an important population for understanding long-term exposure and potential intra-household transmission; however, data on viral infections and co-infections among couples in rural Tanzania are limited. This study aimed to determine the seroprevalence and patterns of HIV, HBV, and HCV mono-infections and co-infections among married couples in Kakonko District, Kigoma Region, western Tanzania. A community-based cross-sectional study was conducted between August and October 2025 among 263 married couples (526 individuals). Finger-prick blood samples were tested for HIV using the national rapid diagnostic testing algorithm, HBV using hepatitis B surface antigen (HBsAg) rapid tests, and HCV using anti-HCV antibody rapid assays. Socio-demographic data were collected using structured questionnaires, and data were analyzed using Stata version 16. Among 526 participants, HIV prevalence was 0.4%, HBV prevalence was 4.5%, and HCV prevalence was 0.4%. HIV–HBV co-infection was identified in one participant (0.19%), while no HIV–HCV, HBV–HCV, or triple infections were detected. Serodiscordant infection was observed in two couples for HIV, eighteen couples for HBV, and two couples for HCV, while HBV seroconcordance was identified in two couples. In conclusion, HBV infection remains moderately prevalent among married couples in Kakonko District, whereas HIV and HCV prevalence are low and viral co-infections are rare. Strengthening HBV screening, adult vaccination, and couple-based education programs is recommended.

HIV, Hepatitis B, Hepatitis C, Co-infection, Married couples, Tanzania