What is required for achieving hepatitis C virus elimination in Singapore? A modeling study

Background and Aim The vast majority of hepatitis C virus (HCV) infection in Singapore is among those with a history of injecting drug use (IDU), yet harm reduction is not available and what is required to achieve the World Health Organization (WHO) HCV elimination targets (80% incidence reduction and 65% mortality reduction by 2030) is unknown. We model the intervention scale‐up required to achieve WHO targets in Singapore. Methods A dynamic model of HCV transmission and progression among those with a history of IDU was calibrated to Singapore, a setting with declining IDU and no harm reduction (~11 000 people with IDU history in 2017 and 45% HCV seropositive). We projected HCV treatment scale‐up from 2019 required to achieve WHO targets with varying prioritization scenarios, with/without opiate substitution therapy scale‐up (to 40% among people who inject drugs [PWID]). Results We estimated 3855 (95% confidence interval: 2635–5446) chronically HCV‐infected individuals with a history of IDU and 148 (87–284) incident HCV cases in Singapore in 2019. Reaching the HCV incidence target requires 272 (187–384) treatments in 2019, totaling 2444 (1683–3452) across 2019–2030. By prioritizing PWID or PWID and cirrhotics, 60% or 30% fewer treatments are required, respectively, whereas the target cannot be achieved with cirrhosis prioritization. Opiate substitution therapy scale‐up reduces treatments required by 21–24%. Achieving both WHO targets requires treating 631 (359–1047) in 2019, totaling 3816 (2664–5423) across 2019–2030. Conclusions Hepatitis C virus elimination is achievable in Singapore but even with declining IDU requires immediate treatment scale‐up among PWID. Harm reduction provision reduces treatments required and provides additional benefits.