Significant amelioration of hepatitis C virus infection in a hyperendemic area: longitudinal evidence from the COMPACT Study in Taiwan.

Objectives: Hepatitis C virus (HCV) infection is the leading cause of cirrhosis and hepatocellular carcinoma worldwide. Tzukuan, located in the southwestern area of Taiwan, is an HCV hyperendemic area (>30%). This study aimed to assess the changing epidemiological characteristics of HCV infection and to evaluate the long-term outcomes after the implementation of public health strategies for two decades.

Design: A population-based retrospective cohort study.

Setting: A comprehensive care programme was implemented, namely COMPACT Study, in Tzukuan since 1997.

Participants: A total of 10 714 residents participated the screening.

Outcome Measures: The HCV status, demographic and clinical profiles of the participants were recorded and validated annually from 2000 through 2019.

Results: The HCV infection prevalence rates were 21.1% (1076/5099) in 2000-2004, 18.8% (239/1269) in 2005-2009, 14.1% (292/2071) in 2010-2014 and 10.3% (234/2275) in 2015-2019 (p for trend test <0.0001). Among them, 1614 underwent repeated tests during the follow-up period. The annual incidence rates were 0.54% in 2005-2009, 0.4% in 2010-2014 and 0.22% in 2015-2019, respectively (p=0.01). In addition to old age, lower education level was a major risk factor for HCV infection across different periods. HCV infection prevalence rate among those illiterates reached 40.9%, followed by 28.5% in those with elementary school level, and <10% in those with high school or higher levels. The major risk factor has shifted from iatrogenic exposure in 2000-2009 to household transmission after 2010.

Conclusions: HCV infection has been decreasing and the epidemiological features are changing in the hyperendemic area by continuing education, prevention and treatment strategies.