SummaryBackgroundPeople who inject drugs (PWID) experience a high prevalence of incarceration and might be at high risk of HIV and hepatitis C virus (HCV) infection during or after incarceration. We aimed to assess whether incarceration history elevates HIV or HCV acquisition risk among PWID.MethodsIn this systematic review and meta-analysis, we searched MEDLINE, Embase, and PsycINFO databases for studies in any language published from Jan 1, 2000 until June 13, 2017 assessing HIV or HCV incidence among PWID. We included studies that measured HIV or HCV incidence among community-recruited PWID. We included only studies reporting original results and excluded studies that evaluated incident infections by self-report. We contacted authors of cohort studies that met the inclusion or exclusion criteria, but that did not report on the outcomes of interest, to request data. We extracted and pooled data from the included studies using random-effects meta-analyses to quantify the associations between recent (past 3, 6, or 12 months or since last follow-up) or past incarceration and HIV or HCV acquisition (primary infection or reinfection) risk among PWID. We assessed the risk of bias of included studies using the Newcastle-Ottawa Scale. Between-study heterogeneity was evaluated using the I2 statistic and the P-value for heterogeneity.FindingsWe included published results from 20 studies and unpublished results from 21 studies. These studies originated from Australasia, western and eastern Europe, North and Latin America, and east and southeast Asia. Recent incarceration was associated with an 81% (relative risk [RR] 1·81, 95% CI 1·40–2·34) increase in HIV acquisition risk, with moderate heterogeneity between studies (I2=63·5%; p=0·001), and a 62% (RR 1·62, 95% CI 1·28–2·05) increase in HCV acquisition risk, also with moderate heterogeneity between studies (I2=57·3%; p=0·002). Past incarceration was associated with a 25% increase in HIV (RR 1·25, 95% CI 0·94–1·65) and a 21% increase in HCV (1·21, 1·02–1·43) acquisition risk.InterpretationIncarceration is associated with substantial short-term increases in HIV and HCV acquisition risk among PWID and could be a significant driver of HCV and HIV transmission among PWID. These findings support the need for developing novel interventions to minimise the risk of HCV and HIV acquisition, including addressing structural risks associated with drug laws and excessive incarceration of PWID.FundingEngineering and Physical Sciences Research Council, National Institute for Health Research, National Institutes of Health.

Objectives To examine the relationship between non-fatal overdose and risk of subsequent fatal overdose. Methods We assessed risk factors for overdose death among two prospective cohorts of persons who inject drugs (PWID) in Vancouver, Canada. Extended Cox regression was used to examine if reports of non-fatal overdose were associated with the time to fatal overdose while adjusting for other behavioral, social and structural confounders. Results Between May, 1996 and December, 2011, 2,317 individuals were followed for a median of 60.8 months. In total, 134 fatal overdose deaths were identified for an incidence density of 8.94 (95% confidence interval [CI]: 7.55 – 10.59) deaths per 1,000 person-years. During the study period there were 1795 reports of non-fatal overdose. In a multivariate model, recent non-fatal overdose was independently associated with the time to overdose mortality (adjusted hazard ratio [AHR] = 1.95; 95% CI: 1.17 - 3.27). As well, there was a dose response effect of increasing cumulative reports of non-fatal overdose on subsequent fatal overdose. Conclusion Reports of recent non-fatal overdose were independently associated with subsequent overdose mortality in a dose-response relationship. These findings suggest that individuals reporting recent non-fatal overdose should be engaged with intensive overdose prevention interventions.

Aims Despite proven benefits of antiretroviral therapy (ART), many HIV-infected injection drug users (IDU) do not access treatment even in settings with free health care. We examined whether methadone maintenance therapy (MMT) increased initiation and adherence to ART among an IDU population with free health care. Design We prospectively examined a cohort of opioid-using antiretroviral-naïve HIV-infected IDU and investigated factors associated with initiation of antiretroviral therapy as well as subsequent adherence. Factors independently associated with time to first initiation of antiretroviral therapy were modelled using Cox proportional hazards regression. Findings Between May 1996 and April 2008, 231 antiretroviral-naïve HIV-infected opioid using IDU were enrolled, among whom 152 (65.8%) initiated ART, for an incidence density of 30.5 (95% confidence interval [CI]: 25.9–35.6) per 100 person-years. After adjustment for time-updated clinical characteristics and other potential confounders, use of MMT was independently associated with more rapid uptake of antiretroviral therapy (relative hazard = 1.62 [95% CI: 1.15–2.28]; p = 0.006). Those prescribed methadone also had higher rates of ART adherence after first antiretroviral initiation (odds ratio = 1.49 [95% CI: 1.07–2.08]; p = 0.019). Conclusion These results demonstrate that MMT contributes to more rapid initiation and subsequent adherence to ART among opioid-using HIV-infected IDU. Addressing international barriers to the use and availability of methadone may dramatically increase uptake of HIV treatment among this population.