Identification of Unrecognized Hepatitis B, C, and D Infections Through the Private Laboratory-Based RE-LINK Screening Project in Romania: A Micro-Elimination Initiative

Background/Objectives: Chronic hepatitis B (HBV) and C (HCV) remain major public health challenges in Romania despite vaccination and antiviral therapy. Understanding infection patterns in different healthcare settings is essential for targeted elimination strategies. Methods: We conducted the prospective screening phase of the RE-LINK project (January–June 2025) through two nationwide private laboratory networks. Adults undergoing routine testing were screened for HBsAg and anti-HCV. HBsAg-positive samples were further analyzed for HBV DNA, HBeAg, anti-HBe, anti-HDV, and HDV RNA, while anti-HCV-positive cases were tested for HCV RNA. Risk factors were assessed using chi-square and logistic regression analyses. Results: Among 9149 individuals (66.6% women with a median age of 53 years), HBsAg prevalence was 2.9%, and anti-HCV was 1.3%, both increasing significantly with age (p < 0.001). Of all HBsAg-positive individuals, 12.5% had undetectable HBV DNA, 70.4% had low viremia (<2000 IU/mL), and 17.1% had high viral loads. Anti-HDV antibodies were detected in 2.3% of HBsAg-positive subjects, all with detectable HDV RNA (range 1250–680,000 IU/mL). Significant risk factors for HBsAg positivity were male sex, older age, urban residence, physician-indicated testing, neuropsychiatric comorbidity, family or parental hepatitis, and institutional/orphanage care, while HBV vaccination and moderate alcohol use were protective. Anti-HCV positivity correlated with older age, cardiovascular disease, elevated transaminases, transfusions, surgery, and HIV co-infection. Only 20.2% of anti-HCV-positive individuals were viremic. Conclusions: Private-laboratory screening reveals residual low-replicative HBV and declining viremic HCV, while community programs uncover HDV and advanced disease in vulnerable groups. A coordinated approach integrating private, community, and hospital-based pathways can accelerate elimination efforts and ensure that HDV is not overlooked.