Mapping the hepatitis C cascade of care in people attending drug treatment services in England: A data linkage study
Number new diagnoses,Linkage to care
Laboratory-based antibody test,Laboratory-based PCR/RNA (confirmatory) test
Introduction: Hepatitis C (HCV) infection in England primarily affects people who inject drugs (PWID). We describe persons HCV tested, estimate incidence and establish the cascade of care (CoC) for people engaging with drug services. Method(s): Persons testing for HCV in drug services in Sentinel Surveillance of Blood Borne Virus Testing (SSBBV) between 2008 and 2016 were linked with people attending drug services in the National Drug and Treatment Monitoring System (NDTMS). We describe risk characteristics, establish the CoC, and estimate HCV incidence in PWID diagnosed in drug services. Result(s): Of 46,721 persons tested for anti-HCV in SSBBV in drug services, 29,773 (63.7%) linked to NDTMS. Of these, 9100 (30.6%) were antiV positive and anti-HCV positivity was 45.0% in persons reporting urgent housing problems and 43.8% in persons reporting ever injecting. Among persons anti-HCV positive, half had >=1 positive anti-HCV test. For persons' first anti-HCV positive between 2008 and 2013 (n = 3123), 74.9% were HCV RNA tested, of whom 71.2% were RNA positive, and of these, 14.0% had evidence of interferon-based treatment, with 52.8% achieving cure. Among PWID, HCV incidence was 8.7 per 100 person-years (95% CI: 8.1-9.2). Conclusion(s): Through record linkage of surveillance datasets, we estimated the HCV CoC for people attending drug services, providing a benchmark from which to monitor the impact of strategies to scale-up prevention, testing, and curative treatment with direct acting antivirals. Our study highlights wasteful repeated testing and poor linkage to care for this high risk population which need to be addressed. Copyright © 2019 Elsevier B.V.