Carole Morissette

High hepatitis C virus prevalence and incidence among Canadian intravenous drug users

We used data and leftover samples collected through the SurvUDI network to describe the epidemiology of hepatitis C virus (HCV) infection among injection drug users (IDUs) in Eastern Central Canada. Among the 1380 selected IDUs, having participated twice or more between 1997 and 2003, the overall HCV prevalence rate was 60.4% (95% confidence interval [CI]: 57.7–63.0%). Among the 543 initially uninfected participants, the HCV incidence rate was 27.1 per 100 person-years (95% CI: 23.4–30.9 per 100 person-years). Independent predictors of seroconversion, identified among 359 participants, were age, injecting for a year or less, injecting with a syringe previously used by someone else, injecting most often cocaine, engaging in prostitution, and being recruited in a major urban centre. The HCV epidemic severely affects IDUs in this area. Actions to prevent HCV transmission, such as distribution of sterile injection equipment, have to be reinforced. Special efforts have to be targeted towards starting IDUs.

Drug use patterns in the presence of crack in downtown Montréal.

INTRODUCTION AND AIMS A study was undertaken to verify reports of an increasing presence of crack in downtown Montréal, and to investigate the influence of crack availability on current drug use patterns among street-based cocaine users. DESIGN AND METHODS The study combined both qualitative and quantitative methods. These included long-term intensive participant observation carried out by an ethnographer familiar with the field and a survey. The ethnographic component involved observations and unstructured interviews with 64 street-based cocaine users. Sampling was based on a combination of snowballing and purposeful recruitment methods. For the survey, structured interviews were conducted with a convenience sample of 387 cocaine users attending HIV/HCV prevention programs, downtown Montréal. RESULTS A gradual shift has occurred in the last 10 years, with the crack street market overtaking the powder cocaine street market. Although the data pointed to an increase in crack smoking, 54.5% of survey participants both smoked and injected cocaine. Drug market forces were major contributing factors to the observed modes of cocaine consumption. While the study focused primarily on cocaine users, it became apparent from the ethnographic fieldwork that prescription opioids (POs) were very present on the streets. According to the survey, 52.7% of participants consumed opioids, essentially POs, with 88% of them injecting these drugs. DISCUSSION AND CONCLUSIONS Despite the increased availability of crack, injection is still present among cocaine users due at least in part to the concurrent increasing popularity of POs.

Temporal changes in risk factors associated with Hiv seroconversion among injection drug users in eastern central Canada

Objectives:To investigate temporal trends in HIV incidence rates and to assess changes over time in associated risk factors. Methods:Since 1995, the SurvUDI network has conducted surveillance among IDUs recruited in harm reduction programmes in eastern central Canada. Among the 11 731 participants, 2903 repeaters were initially HIV-negative. HIV incidence was calculated and compared for two time periods (1995–2002 vs. 2003–2009). Multivariate Cox proportional hazard models with time-dependent covariates were used to assess risk factors associated with HIV seroconversion. Interactions between covariates and time periods were examined. Results:The overall HIV incidence rate was 2.7 per 100 person-years [95% confidence interval (CI) 2.4–3.1]. It significantly decreased from 3.1 per 100 person-years in 1995–2002 to 2.2 person-years in 2003–2009. Sex, needle borrowing, and cocaine as most often injected drug were independent and stable determinants of HIV seroconversion. Age, daily injection, sex work and being recruited in an urban area showed significant interactions with time. Being aged 25 years and older, injecting daily and being recruited in an urban area predicted HIV incidence in 1995–2002 but were no longer risk factors in 2003–2009. HIV incidence increased significantly among younger IDUs and sex work emerged as a new determinant of HIV incidence in 2003–2009. Conclusion:HIV incidence has decreased over time but remains high among IDUs in eastern central Canada. Associations between risk factors and HIV incidence have changed. Further research is needed to better understand HIV transmission among younger IDUs and IDU sex workers.

Access to Sterile Injecting Equipment is More Important Than Awareness of HCV Status for Injection Risk Behaviors Among Drug Users

Awareness of hepatitis C virus (HCV) infection status is expected to influence risk behaviors. In 2004–2005, injection drug users (IDUs) recruited from syringe exchange programs (SEPs) and methadone clinics in Montreal, Canada, were interviewed on drug use behaviors (past 6 months) and HCV testing. Subjects (n = 230) were classified as low/intermediate risk (20.4% borrowed drug preparation equipment only) and high risk (19.6% borrowed syringes), and 54.5% reported being HCV positive. Logistic regression modeling showed that compared to no risk (60% borrowed nothing), low/intermediate risk was associated with fewer noninjecting social network members, poor physical health, and problems obtaining sterile injecting equipment. High risk was associated with all of these factors except social networks. HCV status was not associated with any level of risk. Improved access to sterile injecting equipment may be more important than knowledge of HCV status in reducing injection risks among this IDU population. The study limitations are noted and recommendations discussed.

Evaluation of a media campaign aimed at preventing initiation into drug injection among street youth

Aims: A campaign to prevent initiation into drug injecting among street youth who have never injected drugs (NIDUs) was carried out in Montréal, Canada in 2005. Evaluation objectives were (1) to assess the campaigns ability to reach NIDU street youth and (2) to understand the campaigns effects on this population. Methods: A survey was conducted, as well as semi-structured interviews. Findings: The campaign enjoyed a high degree of visibility. It spoke to young NIDUs, causing them to reflect on both drug injecting and their own non-injection drug use. The campaign had a positive impact in terms of their views on drug injecting. Despite its limited scope, young NIDUs also considered the campaign to be a tool with the potential to contribute to preventing initiation into drug injecting among their peers. Conclusions: Media prevention campaigns are able to reach hidden populations through the use of bold and innovative techniques. Such campaigns can also contribute to influencing the attitudes and perceptions of these populations. However, more comprehensive injection prevention programs need to be established.

Estimating the size of the population of persons who inject drugs in the island of Montréal, Canada, using a six-source capture-recapture model.

BACKGROUND To plan and implement services to persons who inject drugs (PWID), knowing their number is essential. For the island of Montréal, Canada, the only estimate, of 11,700 PWID, was obtained in 1996 through a capture-recapture method. Thirteen years later, this study was undertaken to produce a new estimate. METHODS PWID were defined as individuals aged 14-65 years, having injected recently and living on the island of Montréal. The study period was 07/01/2009 to 06/30/2010. An estimate was produced using a six-source capture-recapture log-linear regression method. The data sources were two epidemiological studies and four drug dependence treatment centres. Model selection was conducted in two steps, the first focusing on interactions between sources and the second, on age group and gender as covariates and as modulators of interactions. RESULTS A total of 1480 PWID were identified in the six capture sources. They corresponded to 1132 different individuals. Based on the best-fitting model, which included age group and sex as covariates and six two-source interactions (some modulated by age), the estimated population was 3910 PWID (95% confidence intervals (CI): 3180-4900) which represents a prevalence of 2.8 (95% CI: 2.3-3.5) PWID per 1000 persons aged 14-65 years. CONCLUSIONS The 2009-2010 estimate represents a two-third reduction compared to the one for 1996. The multisource capture-recapture method is useful to produce estimates of the size of the PWID population. It is of particular interest when conducted at regular intervals thus allowing for close monitoring of the injection phenomenon.

Prevalence and temporal trends of crack injection among injection drug users in eastern central Canada.

BACKGROUND Little is known about crack injection and its temporal trends in North America. This article describes the extent of crack injection and examines temporal trends among injection drug users (IDUs) recruited from 2003 to 2010 in the SurvUDI network. METHODS IDUs who injected recently (past 6 months) were recruited in harm reduction and health programs in eastern central Canada. Trend analyses were performed using generalized estimating equations. Some IDUs participated multiple times; first interview was retained for the descriptive analyses, while first interview per year was retained for the trend analyses. RESULTS Of the 4088 IDUs recruited, 15.2% (621) reported crack injection; large variations across sites were noted (range: 0.3-39.5%). Trend analyses were limited to Ottawa (449 crack injectors) and Montréal (121). For Ottawa, a significant decline was observed, from 48.3% to 36.9%, with a prevalence ratio (PR) of 0.97 per year (95% CI: 0.94-0.99). For Montréal, a significant rise was observed, from 6.0% to 18.4%, with a PR of 1.29 per year (95% CI: 1.19-1.40). CONCLUSIONS Strong variations in crack injection exist throughout the SurvUDI network, and reversed temporal trends have been observed in Ottawa and Montréal. These data will be useful to local harm reduction programs to evaluate the need to distribute items required by crack injectors and to develop prevention messages.

Impact of sex work on risk behaviours and their association with HIV positivity among people who inject drugs in Eastern Central Canada: cross-sectional results from an open cohort study

Objectives The objectives of this study were: (1) to examine the correlates of HIV positivity among participants who injected drugs and engaged in sex work (PWID-SWs) in the SurvUDI network between 2004 and 2016, after stratification by sex, and (2) to compare these correlates with those of sexually active participants who did not engage in sex work (PWID non-SWs). Design and setting This biobehavioural survey is an open cohort of services where participants who had injected in the past 6 months were recruited mainly through harm reduction programmes in Eastern Central Canada. Participants Data from 5476 participants (9223 visits in total; 785 not included in multivariate analyses due to missing values) were included. Methods Participants completed an interviewer-administered questionnaire and provided saliva samples for anti-HIV antibody testing. Generalised estimating equations taking into account multiple participations were used. Results Baseline HIV prevalence was higher among SWs compared with non-SWs (women: 13.0% vs 7.7%; P<0.001, and men: 17.4% vs 10.8%; P<0.001). PWID-SWs were particularly susceptible to HIV infection as a result of higher levels of vulnerability factors and injection risk behaviours. They also presented different risk-taking patterns than their non-SWs counterparts, as shown by differences in correlates of HIV positivity. Additionally, the importance of sex work for HIV infection varies according to gender, as suggested by a large proportion of injection risk behaviours associated with HIV among women and, conversely, a stronger association between sexual behaviours and HIV positivity observed among men. Conclusion These results suggest that sex work has an impact on the risk of HIV acquisition and that risk behaviours vary according to gender. Public health practitioners should take those specificities into account when designing HIV prevention interventions aimed at PWIDs.

Drug use practices among people who inject drugs in a context of drug market changes: Challenges for optimal coverage of harm reduction programs

BACKGROUND Until the early 2000s, people who inject drugs (PWID) in Québec had mainly been injecting powder cocaine and heroin. Since then, ethnographic studies have shown that the drug market has diversified, with crack and prescription opioids (PO) becoming increasingly available. This could have led to changes in drug use practices among PWID. The objectives of our study were to examine annual trends in injection of different drugs, crack smoking and frequent injection (FI), as well as relationships between injected drugs and FI. METHODS PWID are participants in the ongoing Québec SurvUDI surveillance system. PWID (past 6 months) were recruited in 2 urban and 6 semi-urban/rural sites. Each visit included a structured interview addressing drug use behaviours. Analyses were carried out using GEE methods. For trend analyses (2003-2014) on drugs and FI (number of injections≥upper quartile, previous month), the first annual interview was selected for PWID with multiple participations per year. Analyses on associations between FI and types of injected drugs were based on all interviews (2004-2014). RESULTS Crack/cocaine and heroin injection declined significantly, with prevalence ratios (PR) per year of 0.983 [95% confidence interval (CI): 0.980-0.986] and 0.979 (95% CI: 0.969-0.990), while PO injection [PR=1.052 (1.045-1.059)], crack smoking [PR=1.006 (1.001-1.012)], and FI (≥120 injections, previous month) significantly increased [PR=1.015 (1.004-1.026)]. Compared to PWID who injected crack/cocaine±other drugs, the proportion of PWID reporting FI was higher among those who injected PO+heroin/speedball, crack/cocaine or other drugs (adjusted PR 2.29; 95% CI: 2.07-2.53) or PO only (aPR 1.72; 95%CI: 1.47-2.01). CONCLUSIONS Changes that have occurred in the drug market are reflected in PWIDs practices. The high frequency of injection observed among PO injectors is of particular concern. Drug market variations are a challenge for health authorities responsible for harm reduction programs.