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Abstract: Background: Unsafe injecting practices put injecting drug users (IDUs) at repeat exposure to infection with the hepatitis C virus (HCV). It has not yet been determined if spontaneously clearing one''s primary infection influences the risk of reinfection; our aim was to estimate the relative risk of reinfection in IDUs who have cleared the virus. Methods: We conducted a retrospective study using a large database of HCV test results covering Greater Glasgow Health Board during 1993–2007 to calculate rates of infection and reinfection in current/former IDUs. The relative risk of (re)infection in previously infected compared with never-infected IDUs was estimated using Poisson regression, adjusting for age at study entry, sex, and calendar period of test. Results: Although the rate of reinfection in IDUs who were HCV antibody-positive, RNA-negative at baseline was lower (7/100 person-years, 95% CI: 5–9) than the rate of acute infection in IDUs who were HCV antibody-negative at baseline (10/100 person-years, 95% CI: 9–12), the risk of reinfection was not significantly different than the risk of initial infection (adjusted rate ratio=0.78, 95% CI: 0.57–1.08). Conclusion: We found only weak evidence for a reduced risk of HCV reinfection in IDUs who had cleared their previous infection. Further research among those who have cleared infection through antiviral therapy is needed to help inform decisions regarding treatment of IDUs. [Copyright &y& Elsevier]

Abstract: Background: We investigated the association between actual and self-reported hepatitis C virus (HCV) status and alcohol consumption among injecting drug users (IDUs) to determine whether IDUs who self-report as HCV infected comply with UK guidelines on safe drinking and to determine risk factors for drinking. Methods: We conducted a repeat cross-sectional survey of IDUs accessing harm reduction services in Glasgow in 2005 and 2007. We measured self-reported weekly alcohol consumption, excess drinking (defined as exceeding the UK Royal College of Physician''s guidelines for safe drinking of 14units/week for women and 21units/week for men) and HCV antibodies (anonymously in oral fluid). Results: Among IDUs who tested HCV antibody positive, 65% drank alcohol and 29% drank to excess, compared to 61% (p =0.3) and 18% (p <0.001) of those who tested negative, respectively. IDUs who self-reported as HCV positive were less likely to drink but as likely to drink to excess as self-reported negatives or those with HCV status unknown, both among all IDUs and those who tested HCV antibody positive. Among the antibody positives, excess drinking was associated with incarceration (aOR=2.56; 95% CI: 1.28–5.12), homelessness within six months of interview (aOR=3.60; 95% CI: 2.00–6.48) and homelessness more than six months before interview (aOR=1.93; 95% CI: 1.06–3.53). Conclusions: IDUs who believe they are HCV infected are more likely to abstain from alcohol, but those who drink continue to do so to excess. IDUs diagnosed with HCV need greater support to reduce their alcohol consumption. [Copyright &y& Elsevier]

We re-analyse data on new diagnoses of Hepatitis C virus (HCV) for injectors in prison or attending general practices which were relied on for the cost-effectiveness of HCV testing in injectors. We use these revised estimates to suggest readily achievable targets in Scottish general practices on HCV diagnoses for injectors born in 1956–1975. Using audit data from general practices around Edinburgh, we confirm that, with effort, the suggested targets are achievable. On re-analysis, we found that over 20% of HCV-undiagnosed injectors in English prisons accepted HCV testing, and half the injectors aged 30–54 years who attended a Glasgow general practice. On the basis of 30% HCV test uptake and 80% of ever-injectors having self-identified, a target of 2500 HCV diagnoses within a year in known ever-injectors born in 1956–1975 attending Scottish general practices is feasible. Its target of five new HCV diagnoses was achieved during an HCV testing intervention by Muirhouse Practice, Edinburgh. During a 2-year audit period, 86 other general practices around Edinburgh providing enhanced services for drug users increased HCV test uptake by known ever-injectors from 43% (314/727) to 62% (655/1062) in the 1956–1975 birth-cohort. Their new HCV diagnoses in ever-injectors were 171 over two years against a target of 166 within 1 year. [ABSTRACT FROM AUTHOR]

The aim of this study was to explore the influence of testing for hepatitis C virus (HCV) and perceived HCV status on injecting risk behavior. A cross-sectional, community-wide survey was undertaken at multiple sites throughout Greater Glasgow during 2001-2002. Four hundred ninety-seven injecting drug users (IDUs) consented to participate and were interviewed using a structured questionnaire to ascertain HCV test history and injecting risk behavior. The average age of participants was 27 years and the majority of the sample were male (70.4%). Participants had been injecting for an average duration of 2.5 years. Logistic regression analysis revealed no significant associations between having been tested and injecting risk behavior. After adjustment for potential confounding variables, HCV-negatives were significantly less likely to borrow needles/syringes and spoons or filters as compared with unawares and were significantly less likely to borrow spoons or filters as compared with HCV-positives. Due to the cross-sectional design of the study, it is uncertain whether this reduction in risk behavior could be attributed to perception of HCV status. Further research is recommended to consolidate the evidence for this relationship. [ABSTRACT FROM AUTHOR]

Background: Few studies of the prevalence of hepatitis C virus (HCV) infection have focussed on women who work as street sex workers to finance their drug use. Methods: The investigators report the survey findings of such a population in Glasgow. All women attending the health and social care drop-in centre, situated in Glasgow's "Red Light Area", during a four-week period in 1999 were invited to participate in a survey involving the provision of a saliva sample for anonymous HCV testing and the self-completion of a questionnaire seeking demographic, sexual and injecting practice data. Results: Of the 223 women who attended, 51% agreed to participate. Of the 98 women who provided a sufficient saliva sample, 64% (95% CI: 54%-74%) tested HCV antibody positive; 98% of those who tested positive had ever injected drugs. Adjusting for the 85% sensitivity of the saliva test, the HCV antibody prevalence among IDU sex workers sampled was 81%; a rate which is considerably higher than those recorded, contemporaneously, among Glasgow IDUs generally. Two factors were independently associated with HCV antibody positivity in saliva: ever shared needles and syringes (adjusted OR 5.7, 95% CI 2-16) and number of times imprisoned (adjusted OR 7.3, 95% CI 1.4-39, for more than five times compared to zero times). Conclusion: Women who engage in street sex work to finance their drug habit are a particularly desperate, chaotic and vulnerable population. This study demonstrates that their HCV infection risk may be greater than that for other IDUs. Those responsible for designing interventions to prevent HCV infection among IDUs should consider the special needs of this group. [ABSTRACT FROM AUTHOR]

Abstract: Stochastic simulation was used to model quantitatively the transmission of HCV through the sharing of used needles/syringes among IDUs in Glasgow. This combined information on (a) the incidence and cessation of injecting drug use, (b) the frequencies with which IDUs injected and shared needles/syringes, and (c) the susceptibility, transmissibility and carriage of HCV infection. The model that considered higher infectivity following infection produced seroprevalences (median: 62–72%) and incidences (18–30 per 100 susceptible injector-years) consistent with observed data during the 1990s. The annual number of new HCV infections among Glasgow IDUs was estimated to be low during 1960–1976 (median: 10–60), rise steeply during the early 1980s to peak in 1985 (1120), stabilise during 1991–1997 (510–610) and rise again during 1998–2000 (710–780). Scenario analyses indicated that 4500 HCV infections (10th–90th percentiles: 2400–7700) had potentially been prevented in Glasgow during 1988–2000 as a result of harm-reduction measures. Also, HCV incidence can be successfully reduced if IDUs who, unavoidably, share needles/syringes confine their borrowing to one person; with this strategy alone, an estimated 5300 HCV infections (10th–90th percentiles: 4100–6700) could have been averted in Glasgow during 1988–2000. Such insights will inform those responsible for developing new ways to prevent HCV transmission among IDU populations. [Copyright &y& Elsevier]

Abstract: Estimation of and trends in the size of injecting drug user (IDU) populations is fundamental to the planning and development of health-care services for this group. In Glasgow, log–linear modelling of capture–recapture data estimated 8490 (95% CI 7490–9720) and 7190 (6090–8620) current IDUs in 1990 and 2000, respectively. Hitherto, however, no consensus had been sought on the size and shape of its IDU epidemic curve. A modified Delphi approach was used to elicit one for Glasgow. Twelve experts were asked to provide their opinion on the prevalence, incidence and cessation of injecting for quinquennia during 1960–2000. Instead of the usual iterative process to refine experts’ consensus, the elicitation of IDU incidence and cessation provided an opportunity, not previously explored, to combine these data and examine coherence with capture–recapture IDU prevalence estimates. Scrutiny of consensus data indicated that experts had underestimated incidence during 1985–1990, and overestimated prevalence during 1995–2000 and cessation during 1985–2000. Coherent median estimates indicated that prevalence (149–557), incidence (28–49) and cessation (1–2%) remained low and stable during 1960–1975, rose steeply between 1975 and 1990 (prevalence from 557 to 8238; incidence from 49 to 1375; cessation from 2 to 10%), and by 2000 there had been a decline in prevalence (6809) and incidence (1195) but a further rise in cessation (15%). Prevalence estimates from capture–recapture studies were essential to anchor experts’ consensus and derive coherent data. Further efforts are required to collect data which allow accurate estimation of the incidence and cessation of IDU. [Copyright &y& Elsevier]

The authors present findings from a Bayesian analysis of Scotland's four primary capture-recapture data sources for 2000 that was carried out to estimate numbers of current injecting drug users by region (Greater Glasgow vs. elsewhere in Scotland), sex (male vs. female), and age group (15–34 years vs. ≥35 years). A secondary goal of the analysis was to obtain Bayesian estimates and credible intervals for the demographic influences on Scotland's drug-related death rate per 100 current injectors. Incorporation of informative priors altered the models with highest posterior probability. Expert opinion on how demography influenced Scottish drug injectors' propensity to be listed in different data sources was taken into account, along with external information about European injectors' drug-related death rates and male:female ratios. Higher drug-related mortality was confirmed in older drug injectors and those outside of Greater Glasgow. Female injectors' lower drug-related death rate was not sustained beyond 34 years of age. The authors recommend that demographic influences be accommodated in behavioral capture-recapture estimation, especially when it is a prelude to secondary analysis, such as the analysis of drug-related death rates presented here. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]