Amanda Weir

Are needle and syringe programmes associated with a reduction in HIV transmission among people who inject drugs: a systematic review and meta-analysis

BACKGROUND Needle and syringe programmes (NSP) aim to reduce the risk of HIV by providing people who inject drugs (PWID) with sterile injecting equipment. A recent review of reviews (ROR) concluded that there was only tentative evidence to support the effectiveness of NSP in reducing HIV. We carried out a systematic review and meta-analysis to assess the association between NSP and HIV transmission. METHODS Relevant primary articles presenting data on the risk of HIV transmission associated with NSP were identified in two stages: (i) from reviews identified in two published RORs (covering the period 1980-2008); and (ii) a literature search of CINAHL, Cochrane Library, EMBASE, MEDLINE and PsychINFO for primary articles published since the most recent high quality review (covering the period 2008-12). Study results were synthesized using random-effects meta-analysis. RESULTS There were 12 studies comprising at least 12 000 person-years of follow-up. Exposure to NSP was associated with a reduction in HIV transmission: pooled effect size 0·66 [95% confidence interval (CI) 0·43, 1·01] across all studies, and 0·42 (95% CI 0·22, 0·81) across six higher quality studies (according to the Newcastle-Ottawa tool). CONCLUSIONS There is evidence to support the effectiveness of NSP in reducing the transmission of HIV among PWID, although it is likely that other harm reduction interventions have also contributed to the observed reduction in HIV risk. NSP should be considered as just one component of a programme of interventions to reduce both injecting risk and other types of HIV risk behaviour.

The impact and effectiveness of pneumococcal vaccination in Scotland for those aged 65 and over during winter 2003/2004

BackgroundFor winter 2003/2004 in Scotland, it was recommended that all those aged 65 and over be eligible to receive 23-valent polysaccharide pneumococcal vaccine (23vPPV), which has been shown to be effective in reducing the risk of invasive pneumococcal disease (IPD). We assessed the success of the vaccination programme by examining the age specific incidence rates of IPD compared to four previous winter seasons and estimating vaccination effectiveness.MethodsWinter season incidence rates of IPD for vaccine targeted (65 years and over) and non-targeted (0–4, 5–34, 35–49, 50–64) age bands were examined for the Scottish population in a retrospective cohort design for winter 2003/2004. Details of all IPD cases were obtained from the central reference laboratory and population vaccine uptake information was estimated from a GP sentinel practice network. Based on the preceding four winter seasons, standardised incidence ratios (SIR) for invasive pneumococcal disease were determined by age-band and sex during winter 2003/2004. Vaccination effectiveness (VE) was estimated using both screening and indirect cohort methods. Numbers needed to vaccinate were derived from VE results using equivalent annual incidence estimates for winter 2003/2004.ResultsOverall vaccination effectiveness using the screening method (adjusted for age and sex) in those aged 65 and over was 61.7% (95%CI: 45.1, 73.2) which corresponded to a number needed to vaccinate of 5206 (95%CI: 4388, 7122) per IPD case prevented. Estimated effectiveness for the same age group using the indirect cohort method was not significant at 51% (95%CI: -278, 94). Reductions in the winter season incidence rate of IPD were highly significant for all those aged 75+: males SIR = 58.8 (95%CI: 41.6, 80.8); females SIR = 70.0 (95%CI: 55.1, 87.8). In the 65–74 years age-group, the reduction for females was significant: SIR = 60.3 (95%CI: 39.3, 88.4), but not for males: SIR = 74.8 (95%CI: 50.8, 106.3). There was no significant protective effect on mortality.ConclusionThe introduction of 23vPPV for those aged 65 and over in Scotland during winter 2003/2004, was accompanied with a reduction of around one third in the incidence of IPD in this age group. Vaccination effectiveness estimates were comparable with those from other developed countries.

Does informing people who inject drugs of their hepatitis C status influence their injecting behaviour? Analysis of the Networks II study.

BACKGROUND People who inject drugs (PWID) are at risk of hepatitis C virus (HCV). It is plausible that PWID who receive a diagnosis of HCV will reduce their injecting risk out of concern for their injecting partners, although evidence for this is currently limited. The aim of this study was to investigate whether informing PWID of their HCV diagnosis was associated with a change in injecting behaviour. METHODS Prospective, longitudinal study of PWID recruited from street drug markets across Melbourne, Australia. Interviews and HCV testing were conducted at 3-monthly intervals. The association between receiving a diagnosis of HCV and (i) injecting frequency and (ii) injecting equipment borrowing, was examined using generalized estimating equations (GEE) analysis. RESULTS Thirty-five individuals received a diagnosis of HCV during the study period. Receiving a diagnosis of HCV was associated with a decrease of 0.35 injections per month (p=0.046) but there was no change in injecting equipment borrowing (p=0.750). CONCLUSIONS A small reduction in injecting frequency was observed in PWID who received a diagnosis of HCV. This finding should be investigated further in larger studies examining a wider range of injecting risk behaviours.

HCV epidemiology in high-risk groups and the risk of reinfection

Injecting risk behaviours among people who inject drugs (PWID) and high-risk sexual practices among men who have sex with men (MSM) are important routes of hepatitis C virus (HCV) transmission. Current direct-acting antiviral treatment offers unique opportunities for reductions in HCV-related liver disease burden and epidemic control in high-risk groups, but these prospects could be counteracted by HCV reinfection due to on-going risk behaviours after successful treatment. Based on existing data from small and heterogeneous studies of interferon-based treatment, the incidence of reinfection after sustained virological response range from 2-6/100 person years among PWID to 10-15/100 person years among human immunodeficiency virus-infected MSM. These differences mainly reflect heterogeneity in study populations with regards to risk behaviours, but also reflect variations in study designs and applied virological methods. Increasing levels of reinfection are to be expected as we enter the interferon-free treatment era. Individual- and population-level efforts to address and prevent reinfection should therefore be undertaken when providing HCV care for people with on-going risk behaviour. Constructive strategies include acknowledgement, education and counselling, harm reduction optimization, scaled-up treatment including treatment of injecting networks, post-treatment screening, and rapid retreatment of reinfections.

Rise in testing and diagnosis associated with Scotland's Action Plan on Hepatitis C and introduction of dried blood spot testing

Background A key aim of the Hepatitis C Action Plan for Scotland was to reduce the undiagnosed population through awareness-raising activities, for general practitioners and those at risk, and the introduction of dried blood spot (DBS) sampling in community drug services to overcome barriers to testing. This study evaluates the impact of these activities on testing and diagnosis. Methods Data on hepatitis C virus (HCV) testing undertaken between January 1999 and December 2011 in Scotlands four largest health boards were analysed. Segmented regression analysis was used to examine changes in testing following the (1) launch of the Action Plan and (2) introduction of DBS testing. Results Between the pre-Action Plan and Action Plan periods, increases were observed in the average number of HCV tests (19 058–29 045), positive tests (1993–2405) and new diagnoses (1221–1367). Since July 2009, 26% of new diagnoses were made in drug services. The trend in the number of positive tests was raised during the Action Plan, compared to pre-Action Plan, particularly in drug services (rate ratio (RR)=1.4, p<0.001) and prisons (RR=1.2, p<0.001); no change was observed in general practice. Following introduction of DBS testing, there was a 3-fold increase in testing (RR=3.5, p<0.001) and 12-fold increase in positives (RR=12.1, p<0.001) in drug services. Conclusions The introduction of DBS sampling in community drug services has made an appreciable contribution to efforts to diagnose the HCV-infected population in Scotland. These findings are important to other countries, with injecting-related HCV epidemics, needing to scale-up testing/case-finding initiatives.

Hepatitis C reinfection following treatment induced viral clearance among people who have injected drugs.

BACKGROUND Although people who inject drugs (PWID) are an important group to receive Hepatitis C Virus (HCV) antiviral therapy, initiation onto treatment remains low. Concerns over reinfection may make clinicians reluctant to treat this group. We examined the risk of HCV reinfection among a cohort of PWID (encompassing all those reporting a history of injecting drug use) from Scotland who achieved a sustained virological response (SVR). METHODS Clinical and laboratory data were used to monitor RNA testing among PWID who attained SVR following therapy between 2000 and 2009. Data were linked to morbidity and mortality records. Follow-up began one year after completion of therapy, ending on 31st December, 2012. Frequency of RNA testing during follow-up was calculated and the incidence of HCV reinfection estimated. Cox proportional hazards regression was used to examine factors associated with HCV reinfection. RESULTS Among 448 PWID with a SVR, 277 (61.8%) were tested during follow-up, median 4.5 years; 191 (69%) received one RNA test and 86 (31%) received at least two RNA tests. There were seven reinfections over 410 person years generating a reinfection rate of 1.7/100py (95% CI 0.7-3.5). For PWID who have been hospitalised for an opiate or injection related cause post SVR (11%), the risk of HCV reinfection was greater [AHR=12.9, 95% CI 2.2-76.0, p=0.002] and the reinfection rate was 5.7/100py (95% CI 1.8-13.3). CONCLUSION PWID who have been tested, following SVR, for HCV in Scotland appear to be at a low risk of reinfection. Follow-up and monitoring of this population are warranted as treatment is offered more widely.

Assessing the cost‐effectiveness of treating chronic hepatitis C virus in people who inject drugs in Australia

To assess the cost‐effectiveness of hepatitis C virus treatment with pegylated interferon alfa‐2a and ribavirin in current and former people who inject drugs (PWID).

Evidence of continued injecting drug use after attaining sustained treatment-induced clearance of the hepatitis C virus: implications for reinfection

BACKGROUND People who inject drugs (PWID) are at the greatest risk of hepatitis C virus (HCV) infection, yet are often denied immediate treatment due to fears of on-going risk behaviour. Our principal objective was to examine evidence of continued injecting drug use among PWID following successful treatment for HCV and attainment of a sustained viral response (SVR). METHODS PWID who attained SVR between 1992 and June 2012 were selected from the National Scottish Hepatitis C Clinical Database. Hospitalisation and mortality records were sourced for these patients using record linkage techniques. Our primary outcome variable was any hospitalisation or death, which was indicative of injecting drugs post-SVR. RESULTS The cohort comprised 1170 PWID (mean age at SVR 39.6y; 76% male). The Kaplan Meier estimate of incurring the primary outcome after three years of SVR was 10.59% (95% CI, 8.75-12.79) After adjusting for confounding, the risk of an injection related hospital episode or death post-SVR was significantly increased with advancing year of SVR: AHR:1.07 per year (95% CI, 1.01-1.14), having a pre-SVR acute alcohol intoxication-related hospital episode: AHR:1.83 (95% CI, 1.29-2.60), and having a pre-SVR opiate or injection-related hospital episode: AHR:2.59 (95% CI, 1.84-3.64). CONCLUSION Despite attaining the optimal treatment outcome, these data indicate that an increasing significant minority of PWID continue to inject post-SVR at an intensity which leads to either hospitalisation or death and increased risk of reinfection.

Mortality and cause of death in a cohort of people who had ever injected drugs in Glasgow: 1982-2012.

BACKGROUND To describe all-cause and cause-specific mortality in a cohort of people who had ever injected drugs (PWID) with a low prevalence of HIV over 20-30 years. METHODS Using a retrospective study design, identifying data from a cohort of PWID recruited between 1982 and 1993 through in-patient drug treatment services were linked to National Records for Scotland deaths data using probabilistic record linkage. We report all-cause and cause-specific mortality rates; standardized mortality ratios (SMR) across time, gender and age were estimated. RESULTS Among 456 PWID, 139 (30.5%) died over 9024 person-years (PY) of follow-up. Mortality within the cohort was almost nine times higher than the general population, and remained elevated across all age groups. The greatest excess mortality rate was in the youngest age group, who were 15-24 years of age (SMR 31.6, 95% CI 21.2-47.1). Drug-related deaths declined over time and mortality was significantly higher among HIV positive participants. Although SMRs declined with follow-up, the SMR of the oldest age group (45-60) was 4.5 (95% CI 3.0-6.9). There were no significant differences in all-cause mortality rates between participants who were 25 years and older at cohort entry compared to younger participants. CONCLUSION Mortality rates remained higher than the general population across all age groups. Screening services that identify a history of injecting drug use may be an opportunity to address risk factors faced by an ageing population of PWID and potentially have implications for future health care planning.

The prevalence of hepatitis C virus among people of South Asian origin in Glasgow – Results from a community based survey and laboratory surveillance

BACKGROUND South Asians often present late with HCV or HBV related liver disease which could have been avoided with early diagnosis and subsequent treatment; however the prevalence of HCV/HBV among South Asians in Glasgow is not known. Accordingly, to inform the need for case finding among this group we aimed to examine the prevalence of Hepatitis C virus (HCV) among South Asians living in Glasgow. METHODS A community-based survey recruited individuals at six mosques and four community centres serving the South Asian community during 2009-2010; participants had predominantly never been HCV tested. Laboratory surveillance data involving all individuals tested for HCV during 1993-2009 were examined and South Asians were identified using Nam Pehchan software. RESULTS In the community-based survey, 2.6% of 1288 participants tested HCV-antibody positive; the prevalence ranged from 0.6% among those born in the UK to 3.1% among those born in Pakistan. The odds of testing HCV-antibody positive were significantly raised among those who had surgery in South Asia (aOR: 5.0, 95% CI: 2.0-12.3) and had either medical/dental treatment or an injection in South Asia (aOR: 2.2, 95% CI: 1.0-5.0). Of 6404 South Asians identified from laboratory surveillance data, 9.3% tested HCV positive. An estimated 38% (330/870) of HCV-infected South Asians living in Glasgow remain undiagnosed. CONCLUSIONS South Asians living in Glasgow, particularly those born outside the UK are at greater risk of HCV infection than the general population. Efforts to increase awareness and testing in this population are warranted.