Opportunistic Screening for Hepatitis B and C in Primary Care Using a Reflex Testing System: A Microelimination Model.

INTRODUCTION: Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections remain a significant public health concern. Achieving the World Health Organization (WHO) elimination targets by 2030 requires more effective detection strategies than risk factor-based screening. This study evaluates an opportunistic screening program implemented in Primary Care, incorporating an automated diagnostic and referral pathway. PATIENTS AND METHODS: Prospective study of universal HBsAg and anti-HCV screening conducted in a Primary Care center in Barcelona. Adults requiring a blood test for any reason between February 2023 and February 2025 were included. Positive cases were directly referred to the Hepatology Department through an automated care pathway. RESULTS: A total of 3,103 individuals were screened (41% male; mean age 51 years). The prevalence of anti-HCV positivity was 2.0%, with 0.35% having active infection; 82% of viremic patients initiated antiviral treatment. HBsAg prevalence was 0.8%, and 92% of referred cases attended specialist care; 17% initiated treatment. A higher number of risk factors was associated with anti-HCV positivity, whereas no predictors of HBsAg positivity were identified. Notably, 45% of patients with detectable HCV RNA and 44% of HBsAg-positive individuals had neither recognized risk factors nor elevated ALT levels. CONCLUSIONS: Automated opportunistic screening in Primary Care is feasible and effective, identifying HBV and HCV infections that would likely remain undetected using risk factor-based screening strategies. This integrated approach may contribute substantially to the micro-elimination of viral hepatitis.