A comparative national survey on the gradual decline of hepatitis C virus prevalence in Thailand, 2004, 2014, and 2024.

This study investigates the seroprevalence and trends of Hepatitis C virus (HCV) infection in Thailand in 2024 through a nationwide serosurvey. A cross-sectional study was conducted from May to July 2024, recruiting 6069 participants aged 6 months to 80 years from four provinces representing Thailand's geographical regions. Serum samples were tested using the Elecsys® HCV Duo-assay, with confirmatory HCV RT-PCR performed on positive cases. The Elecsys® HCV Duo-assay identified 0.33% (20/6069) of participants as positive; among these, 0.18% were anti-HCV positive, and 0.26% were HCVcAg positive. Notably, seven cases were confirmed positive by RT-PCR. Participants born before 1992 (aged ≥ 32 years) exhibited a significantly higher seroprevalence compared to those aged < 32 years (p < 0.001). Comparative national estimates from 2004, 2014, and 2024 revealed a substantial decline in anti-HCV seroprevalence, from 2.15 to 0.94% and then to 0.56%, particularly among the general population under 40 years old. Correspondingly, HCV viremia gradually declined from 1.00 to 0.39% and subsequently to 0.36%, respectively. Thailand has made significant progress in reducing HCV seroprevalence over the past two decades, attributed to effective preventive measures policies. However, targeted interventions in high-risk and older populations remain essential to achieve the WHO's goal of HCV elimination by 2030.