Geng Zang

The rising prevalence of prescription opioid injection and its association with hepatitis C incidence among street-drug users

AIMS   To examine trends in prescription opioid (PO) injection and to assess its association with hepatitis C virus (HCV) seroconversion among injection drug users (IDUs). DESIGN   Prospective cohort study. SETTING   Montreal, Canada. PARTICIPANTS   HCV-negative IDUs at baseline, reporting injection in the past month. MEASUREMENTS   Semi-annual visits included HCV antibody testing and an interview-administered questionnaire assessing risk behaviours. HCV incidence rate was calculated using the person-time method. Time-updated Cox regression models were conducted to examine predictors of HCV incidence. FINDINGS   The proportion of IDUs reporting PO injection increased from 21% to 75% between 2004 and 2009 (P < 0.001). Of the 246 participants (81.6% male; mean age 34.5 years; mean follow-up time 23 months), 83 seroconverted to HCV [incidence rate: 17.9 per 100 person-years; 95% confidence interval (CI) 14.3, 22.1]. Compared to non-PO injectors, PO injectors were more likely to become infected [adjusted hazard ratio (AHR): 1.87; 95%CI:1.16, 3.03]. An effect modification was also found: PO injectors who did not inject heroin were more likely to become infected (AHR: 2.88; 95%CI: 1.52, 5.45) whereas no association was found for participants using both drugs (AHR: 1.19; 95% CI: 0.61, 2.30). Other independent predictors of HCV incidence were: cocaine injection, recent incarceration and >30 injections per month. CONCLUSIONS   Prescription opioid injectors who do not inject heroin are at greater risk for HCV seroconversion than are those injecting both heroin and prescription opioids. Important differences in age, behaviour and social context suggest a need for targeted outreach strategies to this population.

Plasma interferon‐gamma‐inducible protein‐10 (IP‐10) levels during acute hepatitis C virus infection

Systemic levels of interferon‐gamma‐inducible protein‐10 (IP‐10) are predictive of treatment‐induced clearance in chronic hepatitis C virus (HCV). In the present study, factors associated with plasma IP‐10 levels at the time of acute HCV detection and the association between IP‐10 levels and spontaneous clearance were assessed in three cohorts of acute HCV infection. Among 299 individuals, 245 (181 male, 47 human immunodeficiency virus‐positive [HIV+]) were HCV RNA+ at acute HCV detection. In adjusted analysis, factors independently associated with IP‐10 levels ≥150 pg/mL (median level) included HCV RNA levels >6 log IU/mL, HIV coinfection and non‐Aboriginal ethnicity. Among 245 HCV RNA+ at acute HCV detection, 214 were untreated (n = 137) or had persistent infection (infection duration ≥26 weeks) at treatment initiation (n = 77). Spontaneous clearance occurred in 14% (29 of 214). Individuals without spontaneous clearance had significantly higher mean plasma IP‐10 levels at the time of acute HCV detection than those with clearance (248 ± 32 versus 142 ± 22 pg/mL, P = 0.008). The proportion of individuals with spontaneous clearance was 0% (0 of 22, P = 0.048) and 16% (27 of 165) and in those with and without plasma IP‐10 levels ≥380 pg/mL. In adjusted analyses, favorable IL28B genotype was associated with spontaneous clearance, while higher HCV RNA level was independently associated with lower odds of spontaneous clearance. Conclusion: High IP‐10 levels at acute HCV detection were associated with failure to spontaneously clear HCV. Patients with acute HCV and high baseline IP‐10 levels, particularly >380 pg/mL, should be considered for early therapeutic intervention, and those with low levels should defer therapy for potential spontaneous clearance. (HEPATOLOGY 2013;)

Sustained Drug Use Changes After Hepatitis C Screening and Counseling Among Recently Infected Persons Who Inject Drugs: A Longitudinal Study

BACKGROUND Notification of hepatitis C virus (HCV) positive status is known to have short-term impacts on subsequent alcohol, drug use and injection behaviors among persons who inject drugs (PWID). It remains to be established whether postscreening behavioral changes extend over time for PWID and whether screening test notification has behavioral impacts among HCV-negative PWID. This study sought to longitudinally assess substance use and injection behaviors after HCV status notification among HCV seroconverters and HCV-negative PWID. METHODS Initially HCV-seronegative PWID (n = 208) were followed prospectively between 2004 and 2011 in Montreal, Canada. Semiannual screening visits included blood sampling and an interview-administered questionnaire assessing substance use and injection behaviors. Multivariable generalized estimating equation analyses were conducted to assess substance use and behavior changes over time and compare changes between HCV seroconverters and HCV-seronegative participants while adjusting for baseline characteristics. RESULTS Of the 208 participants (83% male; mean age, 34.7 years, mean follow-up time, 39 months), 69 (33.2%) seroconverted to HCV. A linear decrease in syringe sharing behavior was observed over time after HCV and status notification, whereas a 10% decrease for each additional 3 months of follow-up was observed for injection cocaine and heroin use among HCV seroconverters but not among HCV-seronegative PWID (P < .05). No significant changes were observed in alcohol use. CONCLUSIONS Our results indicate that notification of HCV-positive status is associated with reduced injection drug use among seroconverters. Among PWID deemed seronegative after screening, there is no sustained trend for change in risk behavior.

Trends in Human Immunodeficiency Virus Incidence and Risk Behavior Among Injection Drug Users in Montreal, Canada: A 16-Year Longitudinal Study

The authors sought to investigate trends in the incidence of human immunodeficiency virus (HIV) infection, evaluate changes in risk behavior, and assess associations between syringe access programs and HIV seroconversion among injection drug users (IDUs) in Montreal, Canada, who were recruited and followed for a prospective cohort study between 1992 and 2008. Methods included Kaplan-Meier survival analysis and time-varying Cox regression models. Of 2,137 HIV-seronegative IDUs at enrollment, 148 became HIV-positive within 4 years (incidence: 3.3 cases/100 person-years; 95% confidence interval: 2.8, 3.9). An annual HIV incidence decline of 0.06 cases/100 person-years prior to 2000 was followed by a more rapid annual decline of 0.24 cases/100 person-years during and after 2000. Behavioral trends included increasing cocaine and heroin use and decreasing proportions of IDUs reporting any syringe-sharing or sharing a syringe with an HIV-positive person. In multivariate analyses, HIV seroconversion was associated with male gender, unstable housing, intravenous cocaine use, and sharing syringes or having sex with an HIV-positive partner. Always acquiring syringes from safe sources conferred a reduced risk of HIV acquisition among participants recruited after 2004, but this association was not statistically significant for participants recruited earlier. In conclusion, HIV incidence has declined in this cohort, with an acceleration of the reduction in HIV transmission after 2000.

Associations between HIV-related injection behaviour and distance to and patterns of utilisation of syringe-supply programmes

Background: Studies indicate that needle-exchange programmes (NEPs) can reduce the incidence of HIV infection; however, a positive impact of syringe-supply programmes has not been consistently demonstrated. The associations between high-risk injection behaviour and distance to and patterns of utilisation of syringe-supply programmes in injection drug users (IDUs) were investigated. Methods: Participants in a cohort of IDUs (n = 456) residing in Montreal were interviewed between 2004 and 2006. Behavioural questionnaires were administered by trained interviewers, and venous blood samples were drawn and tested for HIV antibodies. The distance from regular IDU dwelling places to nearest NEP or pharmacy was calculated using a Geographic Information System. Logistic regression was used to assess relations with high-risk injection behaviour. Results: Associations between high-risk injection behaviour and distance to syringe-supply source were not linear. The odds of high-risk behaviour grew modestly as distance from the NEP site increased to 1600 m, followed by a flat trend to 3000 m, and thereafter decreased with distance beyond this point. The odds of high-risk behaviour dropped sharply for the relatively few IDUs residing 1 km or more from the nearest pharmacy but this measure was not strongly associated with the outcome. IDUs who exclusively acquired syringes at NEPs or pharmacies had less than half the odds of reporting high-risk injection behaviour than IDUs with inconsistent syringe-access patterns. Conclusions: The study confirms that Montreal NEPs were implemented where they are most needed. These results also suggest that sterile syringe acquisition patterns might influence high-risk injection behaviour.

Community-level income inequality and mortality in Québec, Canada

OBJECTIVES Evidence of the association between income inequality and mortality for small rather than large areas is conflicting. This study evaluated community-level income inequality in relation to age- and cause-specific mortality. STUDY DESIGN Ecological analysis. METHODS Mortality data were extracted from the Québec, Canada registry for 1999-2003. For Québec communities (n=143), directly standardized mortality rates were calculated for all-cause (overall, working-age and post-working-age), suicide, alcohol, tobacco and cardiovascular mortality. Using 2001 Canada Census data, the tertiles of income inequality measured as the decile ratio, coefficient of variation and median share were calculated. The relative risk (RR) of death was determined using Poisson regression, accounting for median community income, family structure and rural-urban area. RESULTS Income inequality was most strongly associated with alcohol-related mortality (RR(CoefficientVariation) 0.85, 95% confidence interval 0.77-0.94), followed by statistically significant but weaker inverse associations with tobacco-related and age-specific all-cause mortality. CONCLUSIONS Income inequality in Québec communities is inversely associated with mortality outcomes, particularly alcohol-related mortality. These associations contrast with positive or null associations observed in studies of larger US and Canadian metropolitan areas, respectively. Community-level studies accounting for individual-level covariates are necessary to clarify the relationship between income inequality and mortality.

Sex, age, deprivation and patterns in life expectancy in Quebec, Canada: a population-based study

BackgroundLittle research has evaluated disparities in life expectancy according to material deprivation taking into account differences across the lifespan between men and women. This study investigated age- and sex-specific life expectancy differentials related to area-level material deprivation for the province of Québec, Canada from 1989-2004.MethodsAge- and sex-specific life expectancy across the lifespan was calculated for three periods (1989-1992, 1995-1998, and 2001-2004) for the entire Québec population residing in 162 community groupings ranked according to decile of material deprivation. Absolute and relative measures were calculated to summarize differences between the most and least deprived deciles.ResultsLife expectancy differentials between the most and least deprived deciles were greatest for men. Over time, male differentials increased for age 20 or more, with little change occurring at younger ages. For women, differentials increased across the lifespan and were comparable to men at advanced ages. Despite gains in life expectancy among men relative to women, differentials between men and women were greater for most deprived relative to least deprived deciles.ConclusionsSimilar to the US, differentials in life expectancy associated with area-level material deprivation increased steadily in Québec from 1989-2004 for males and females of all ages. Differentials were comparable between men and women at advanced ages. Previous research indicating that life expectancy differentials between most and least deprived areas are greater in men may be due to a focus on younger age groups.

Availability of body art facilities and body art piercing do not predict hepatitis C acquisition among injection drug users in Montreal, Canada: Results from a cohort study

BACKGROUND Cross-sectional associations suggest that body art piercing (BAP) is a risk factor for hepatitis C (HCV) infection among injection drug users. The temporal basis of the relationship has not been established. METHODS Associations between HCV seropositivity, HCV incidence, recent BAP and BAP facility availability were evaluated among IDUs followed biannually between 2004 and 2008 in Montreal, Canada. A geographic information system was used to determine the availability of BAP facilities for each participant. Statistical models included individual and neighbourhood covariates. Logistic regression was used for analysis of HCV seropositivity. Cox proportional hazards regression was used for analysis of HCV incidence. RESULTS Of 784 IDUs, 73% were seropositive for HCV. In multivariable logistic regression, HCV seropositivity was associated with BAP availability (OR: 1.32 95% confidence interval (CI): 1.1, 1.6) but not recent BAP. Of 145 initially HCV-negative participants, 52 seroconverted to HCV for an incidence of 27.7/100 person-years (95%CI: 20.9, 36.0). Crude hazard ratios (HR) for the association between HCV infection and BAP variables were: recent BAP, HR 0.98 (95%CI: 0.4, 2.7) and BAP facilities availability, HR 1.43 (95%CI: 1.1, 1.9). After accounting for individual and neighbourhood factors, crude associations between HCV infection and recent BAP and BAP facilities availability were: HR recent BAP, 0.96, 95%CI: 0.3, 2.7; and HR BAP facility availability, 1.21, 95%CI: 0.9, 1.7. CONCLUSION BAP facility availability is a marker of neighbourhood disadvantage associated with HCV seropositivity. Longitudinal analyses accounting for behaviour risk factors and neighbourhood characteristics do not support a temporal association between BAP acquisition, BAP facility availability, and HCV infection among IDUs.

Associations of substance use patterns with attempted suicide among persons who inject drugs: Can distinct use patterns play a role?

BACKGROUND While the elevated risk of suicide attempt among persons who inject drugs (PWID) is well documented, whether use of different substances is associated with varying degrees of risk remains unclear. We sought to examine the associations between substance use patterns and attempted suicide in a prospective cohort of PWID in Montreal, Canada. METHODS Between 2004 and 2011, participants completed an interviewer-administered questionnaire eliciting information on socio-demographics, substance use patterns, related behaviors, and mental health markers. Generalized estimating equations were used to model the relationship between self-reported use of six common substances (cocaine, amphetamine, opioids, sedative-hypnotics, cannabis and alcohol), associated patterns of use (chronic, occasional and none), and a recent (past six-month) suicide attempt. RESULTS At baseline, of 1240 participants (median age: 39.1, 83.7% male), 71 (5.7%) reported a recent suicide attempt. Among 5621 observations collected during follow-up, 221 attempts were reported by 143 (11.5%) participants. In multivariate analyses adjusting for socio-demographics and psychosocial stressors, among primary drugs of abuse, chronic [adjusted odds ratio (AOR): 1.97] and occasional (AOR: 1.92) cocaine use, and chronic amphetamine use (AOR: 1.96) were independently associated with attempted suicide. Among co-used substances, chronic sedative-hypnotic use was independently associated with an attempt (AOR: 2.29). No statistically significant association was found for the remaining substances. CONCLUSION Among PWID at high risk of attempted suicide, stimulant users appear to constitute a particularly vulnerable sub-group. While the mechanisms underlying these associations remain to be elucidated, findings suggest that stimulant-using PWID should constitute a prime focus of suicide prevention efforts.

Visits to primary care physicians among persons who inject drugs at high risk of hepatitis C virus infection: room for improvement

The role of primary care physicians (PCP) in hepatitis C virus (HCV) prevention is increasingly emphasized. Yet, little is known about the patterns of contacts with PCP among persons who inject drugs (PWID). We sought to assess the 6‐month prevalence of PCP visiting among PWID at risk of HCV infection and to explore the associated factors. Baseline data were collected from HCV‐seronegative PWID recruited in HEPCO, an observational Hepatitis Cohort study (2004–2011) in Montreal, Canada. An interviewer‐administered questionnaire elicited information on socio‐demographic factors, drug use patterns and healthcare services utilization. Blood samples were tested for HCV antibodies. Using the Gelberg‐Andersen Behavioral Model, hierarchical logistic regression analyses were conducted to identify predisposing, need and enabling factors associated with PCP visiting. Of the 349 participants (mean age = 34; 80.8% male), 32.1% reported visiting a PCP. In the multivariate model, among predisposing factors, male gender [adjusted odds ratio (AOR) = 0.45 (0.25–0.83)], chronic homelessness [AOR = 0.08 (0.01–0.67)], cocaine injection [AOR = 0.46 (0.28–0.76)] and reporting greater illegal or semi‐legal income [AOR = 0.48 (0.27–0.85)] were negatively associated with PCP visits. Markers of need were not associated with the outcome. Among enabling factors, contact with street nurses [AOR = 3.86 (1.49–9.90)] and food banks [AOR = 2.01 (1.20–3.37)] was positively associated with PCP visiting. Only one third of participating PWID reported a recent visit to a PCP. While a host of predisposing factors seems to hamper timely contacts with PCP among high‐risk PWID, community‐based support services may play an important role in initiating dialogue with primary healthcare services in this population.