Progressing towards global hepatitis C elimination: a systematic review and meta-analysis of care cascades in key populations

Background: Hepatitis C virus (HCV) remains a global health concern, with cascade gaps hindering elimination. We aim to assess and compare HCV care cascades in four key populations: people living with HIV (PLHIV), people who inject drugs (PWID), men who have sex with men (MSM), and incarcerated individuals. Methods: We conducted a systematic review and meta-analysis of observational studies (Jan 2019-Sept 2025) reporting ≥1 care cascade stage, including screening, confirmatory testing, linkage to care, treatment uptake and completion, and cure, among key populations (PROSPERO CRD42024577740). Four databases were searched. Pooled stage-specific proportions were estimated using random-effects meta-analysis, stratified by population and region. Findings: We included 219 studies (884,450 individuals) from 46 countries. HCV screening coverage remained suboptimal across populations and was lowest in MSM, below 70% in half of countries. Linkage-to-care data were limited yet indicated low linkage in most countries. Treatment uptake was the weakest stage: 90% of those treated completed therapy and >85% were assessed for SVR. In contrast, indicators were substantially worse in lower-income countries, with gaps across stages. Interpretation: Suboptimal HCV screening, weak care linkage, treatment gaps, and regional inequities persist. Enhanced integrated services, better screening, expanded access, and robust data systems are critical to accelerate elimination in resource-limited settings. Funding: National Natural Science Foundation of China.