Background Peer support can enable patient engagement with healthcare services, particularly for marginalised populations. In this randomised controlled trial, the efficacy of a peer support intervention at promoting successful engagement with clinical services for chronic hepatitis C was assessed. Methods In London, UK, potential participants were approached through outreach services for problematic drug use and homelessness. Individuals positive for hepatitis C virus (HCV) after confirmatory testing were randomised using an online service to the intervention (peer support) or standard of care. The primary outcome of interest was successful engagement with clinical hepatitis services. The study was non-blinded. Absolute differences were calculated using a generalised linear model and the results compared to logistic regression. Results Three hundred sixty-four individuals consented to participate. One hundred one had chronic hepatitis C and were randomised, 63 to receive the intervention (peer support). A successful outcome was achieved by 23 individuals in this arm (36.5%) and seven (18.4%) receiving the standard of care, giving an absolute increase of 18.1% (95% confidence interval 1.0–35.2%, p value = 0.04). This was mirrored in the logistic regression (odds ratio 2.55 (0.97–6.70), p = 0.06). No serious adverse events were reported. Conclusions Peer support can improve the engagement of patients with chronic HCV with healthcare services. Trial registration ISRCTN24707359 . Registered 19th October 2012. Electronic supplementary material The online version of this article (10.1186/s12916-019-1300-2) contains supplementary material, which is available to authorized users.

Treatment as Prevention (TasP) using directly-acting antivirals has been advocated for Hepatitis C Virus (HCV) in people who inject drugs (PWID), but treatment is expensive and TasP’s effectiveness is uncertain. Previous modelling has assumed a homogeneously-mixed population or a static network lacking turnover in the population and injecting partnerships. We developed a transmission-dynamic model on a dynamic network of injecting partnerships using data from survey of injecting behaviour carried out in London, UK. We studied transmission on a novel exponential-clustered network, as well as on two simpler networks for comparison, an exponential unclustered and a random network, and found that TasP’s effectiveness differs markedly. With respect to an exponential-clustered network, the random network (and homogeneously-mixed population) overestimate TasP’s effectiveness, whereas the exponential-unclustered network underestimates it. For all network types TasP’s effectiveness depends on whether treated patients change risk behaviour, and on treatment coverage: higher coverage requires fewer total treatments for the same health gain. Whilst TasP can greatly reduce HCV prevalence, incidence of infection, and incidence of reinfection in PWID, assessment of TasP’s effectiveness needs to take account of the injecting-partnership network structure and post-treatment behaviour change, and further empirical study is required.

Background In the UK, hepatitis B virus (HBV) incidence is associated with migrants from particular high-burden countries and population groups deemed ‘hard-to-reach’ by standard healthcare services: the homeless, people who inject drugs and ex-prisoners. Currently, there is a national targeted HBV vaccine policy for such at-risk groups, but there is limited recent evidence about 1) the levels of vaccine uptake, 2) the factors associated with incomplete vaccination, and 3) reasons for incomplete vaccination. Methods A questionnaire capturing social and medical history, demographic factors and information about HBV vaccination status was completed by individuals deemed hard-to-reach due to socio-structural factors that criminalise, isolate and stigmatise who consented to participate in a randomised controlled trial of a peer intervention to promote engagement with hepatitis C services. The questionnaire also captured the reasons for incomplete vaccination. Descriptive, univariable and multivariable regression analyses were undertaken. Results Three hundred fourty six participants completed the questionnaire. 1) 52.3% ( n = 181) reported full HBV vaccination. 2) Within a multivariable model adjusting for sociodemographic variables, the presence of one or two or more socio-structural factors that are included in the national targeted vaccination policy was associated with protection against incomplete HBV vaccination (51.7% vaccine coverage in those with one factor, odds ratio 0.43 [95% confidence interval 0.20–0.92]); 70.1% coverage with two or more factors, 0.19 [0.09–0.39]; overall p -value < 0.001). Being female was also associated with lower vaccine uptake (2.37 [1.24–4.57], 0.01). Examining the socio-structural factors individually, intravenous drug use was associated with protection against incomplete HBV vaccination. 3) The most common reasons declared for incomplete vaccination were never being offered the vaccine or not returning for further doses. Conclusion Within this study of HBV vaccination uptake among hard-to-reach population groups in London, UK, we document 52.3% coverage of the full vaccine course. Critically, although participants recommended for immunisation within national guidelines had an increased likelihood of receiving a complete vaccine course, we note surprisingly low coverage in the presence of the risk factors that are national indicators for vaccination. Public health bodies should make additional efforts to improve coverage in the hard-to-reach through improved vaccine delivery systems. Trial registration ISRCTN24707359 , Registered 19th October 2012. Electronic supplementary material The online version of this article (10.1186/s12879-019-3926-2) contains supplementary material, which is available to authorized users.

Background HCV infection disproportionately affects underserved populations such as homeless individuals, people who inject drugs and prison populations. Peer advocacy can enable active engagement with healthcare services and increase the likelihood of favourable treatment outcomes. Objectives This observational study aims to assess the burden of disease in these underserved populations and describe the role of peer support in linking these individuals to specialist treatment services. Methods Services were identified if they had a high proportion of individuals with risk factors for HCV, such as injecting drug use or homelessness. Individuals were screened for HCV using point-of-care tests and a portable FibroScan. All positive cases received peer support for linkage to specialist care. Information was gathered on risk factors, demographics and follow-up information regarding linkage to care and treatment outcomes. Results A total of 461 individuals were screened, of which 197 (42.7%) were chronically infected with HCV. Referral was made to secondary care for 176 (89.3%) and all received peer support, with 104 (52.8%) individuals engaged with treatment centres. Of these, 89 (85.6%) started treatment and 76 (85.4%) had a favourable outcome. Factors associated with not being approved for treatment were recent homelessness, younger age and current crack cocaine injecting. Conclusions Highly trained peer support workers working as part of a specialist outreach clinical team help to identify a high proportion of individuals exposed to HCV, achieve high rates of engagement with treatment services and maintain high rates of treatment success amongst a population with complex needs.