Community-Based Micro-Elimination of Hepatitis C Virus in a Defined Rural Cohort: Outcomes From the Nagawa Project.

Background and aims: Hepatitis C virus (HCV) infection remains a global public health concern, with many carriers remaining undiagnosed because of its asymptomatic nature. Although Japan was previously considered to be on track for national HCV elimination by 2030, recent global modeling studies and updated elimination dashboards indicate that Japan is currently not on track. This underscores the importance of locally coordinated efforts to detect residual cases. Micro-elimination has recently emerged as a pragmatic and scalable approach by targeting defined populations or geographic areas. The Nagawa Project sought to identify HCV positive individuals through community-wide screening and directing viremic cases to appropriate direct-acting antiviral (DAA) therapy. The present study describes the implementation and outcomes of this cohort-based HCV micro-elimination strategy.

Methods: All 5027 adult residents of Nagawa town, Japan, aged ≥ 20 years were prospectively targeted for HCV antibody testing through routine health check-ups, outpatient visits, and mailed invitations between June 2021 and March 2024. HCV Antibody positive individuals underwent additional HCV core antigen testing to confirm viremia.

Results: A total of 3121 residents (62.1%) underwent HCV antibody testing. Testing rates were significantly higher in early-stage elderly (65-74 years; 73.7%) residents than in both adult (20-64 years; 54.5%) (p < 0.001) and late-stage elderly (≥ 75 years; 66.7%) (p < 0.001) residents. Twenty-eight individuals (0.897%) were HCV antibody positive, with three cases (0.096%) confirmed as viremic. Antibody positivity was significantly higher in late-stage elderly residents (1.91%; p < 0.001 vs. adult and p = 0.031 vs. early-stage elderly residents). Two viremic individuals received DAA therapy and achieved a sustained virological response. After adjusting for age and sex by propensity score matching, no significant difference in overall survival was observed between HCV antibody positive and negative individuals.

Conclusion: The Nagawa Project illustrates the success of a locally coordinated HCV micro-elimination approach. It offers a practical framework for identifying and managing residual HCV infections, contributing to progress toward Japan's alignment with the World Health Organization's 2030 HCV elimination goals.