Evaluating the population impact of hepatitis C direct acting antiviral treatment as prevention for people who inject drugs (EPIToPe) - a natural experiment (protocol).

INTRODUCTION: Hepatitis C virus (HCV) is the second largest contributor to liver disease in the UK, with injecting drug use as the main risk factor among the estimated 200 000 people currently infected. Despite effective prevention interventions, chronic HCV prevalence remains around 40% among people who inject drugs (PWID). New direct-acting antiviral (DAA) HCV therapies combine high cure rates (>90%) and short treatment duration (8 to 12 weeks). Theoretical mathematical modelling evidence suggests HCV treatment scale-up can prevent transmission and substantially reduce HCV prevalence/incidence among PWID. Our primary aim is to generate empirical evidence on the effectiveness of HCV 'Treatment as Prevention' (TasP) in PWID. METHODS AND ANALYSIS: We plan to establish a natural experiment with Tayside, Scotland, as a single intervention site where HCV care pathways are being expanded (including specialist drug treatment clinics, needle and syringe programmes (NSPs), pharmacies and prison) and HCV treatment for PWID is being rapidly scaled-up. Other sites in Scotland and England will act as potential controls. Over 2 years from 2017/2018, at least 500 PWID will be treated in Tayside, which simulation studies project will reduce chronic HCV prevalence among PWID by 62% (from 26% to 10%) and HCV incidence will fall by approximately 2/3 (from 4.2 per 100 person-years (p100py) to 1.4 p100py). Treatment response and re-infection rates will be monitored. We will conduct focus groups and interviews with service providers and patients that accept and decline treatment to identify barriers and facilitators in implementing TasP. We will conduct longitudinal interviews with up to 40 PWID to assess whether successful HCV treatment alters their perspectives on and engagement with drug treatment and recovery. Trained peer researchers will be involved in data collection and dissemination. The primary outcome - chronic HCV prevalence in PWID - is measured using information from the Needle Exchange Surveillance Initiative survey in Scotland and the Unlinked Anonymous Monitoring Programme in England, conducted at least four times before and three times during and after the intervention. We will adapt Bayesian synthetic control methods (specifically the Causal Impact Method) to generate the cumulative impact of the intervention on chronic HCV prevalence and incidence. We will use a dynamic HCV transmission and economic model to evaluate the cost-effectiveness of the HCV TasP intervention, and to estimate the contribution of the scale-up in HCV treatment to observe changes in HCV prevalence. Through the qualitative data we will systematically explore key mechanisms of TasP real world implementation from provider and patient perspectives to develop a manual for scaling up HCV treatment in other settings. We will compare qualitative accounts of drug treatment and recovery with a 'virtual cohort' of PWID linking information on HCV treatment with Scottish Drug treatment databases to test whether DAA treatment improves drug treatment outcomes. ETHICS AND DISSEMINATION: Extending HCV community care pathways is covered by ethics (ERADICATE C, ISRCTN27564683, Super DOT C Trial clinicaltrials.gov: NCT02706223). Ethical approval for extra data collection from patients including health utilities and qualitative interviews has been granted (REC ref: 18/ES/0128) and ISCRCTN registration has been completed (ISRCTN72038467). Our findings will have direct National Health Service and patient relevance; informing prioritisation given to early HCV treatment for PWID. We will present findings to practitioners and policymakers, and support design of an evaluation of HCV TasP in England.

Spore forming bacteria infections and people who inject drugs: Implications for harm reduction.

BACKGROUND: There is no research on public health interventions that alert people who inject drugs (PWID) to clusters/outbreaks of severe bacterial infections. In Scotland, during the botulism cluster/outbreak of Dec 2014-July 2015 harm reduction (HR) messages detailed on a postcard (Botulism Postcard) were distributed to PWID between Feb-April 2015. We examined the impact of the Botulism Postcard on cluster/outbreak awareness, healthcare seeking and HR behaviours among PWID; and their views on such clusters/outbreaks. METHODS: The Botulism Postcard questionnaire survey was undertaken with 288 PWID recruited in Greater Glasgow and Clyde between May-August 2015. Multivariate logistic regression was undertaken. Between Oct 2015-January 2016 22 in-depth interviews were conducted with PWID in Glasgow and Edinburgh, these underwent thematic analysis. RESULTS: 38% (108/284) had never seen the postcard, 14% (40/284) had only seen it, 34% (98/284) read but not discussed it and 13% (38/284) had discussed it with service staff. Cluster/outbreak awareness was higher among those who had read (adjusted odds ratio (aOR) = 5.374, CI 2.394-11.349, p < 0.001) or discussed the postcard (aOR = 25.114, CI 3.188-190.550, p < 0.001); and symptom awareness was higher among those who had read (aOR = 2.664, CI 1.322-4.890, p < 0.001) or discussed the postcard (aOR = 6.707, CI 2.744 16.252, p < 0.001) than among those who had never seen it. The odds of introducing HR was higher among those who had discussed the postcard (AOR = 3.304 CI 1.425 7.660, p < 0.01) than those who had only read it. PWID learnt about clusters/outbreaks from several sources and despite concerns they continued to inject during such events. CONCLUSION: More widespread exposure to the Botulism Postcard during the outbreak/cluster was needed. The Botulism Postcard distributed to PWID may raise awareness of such events, the symptoms, and may encourage HR particularly when used as a tool by frontline staff to initiate discussion. Acknowledging that people continue to inject during clusters/outbreaks of such infections necessitates a pragmatic HR approach.