HIV and HCV seroincidence, associated factors and drug use in people who inject drugs, SurvUDI network, eastern central Canada, 1995-2020.

BACKGROUND: The SurvUDI network is a biobehavioural survey among people who inject drugs (PWID) in Eastern Central Canada. OBJECTIVES: The objectives were to describe HIV and HCV seroincidence trends, associated factors and changes in drug use behaviours. METHODS: The network was initiated in 1995 and targets hard-to-reach, mostly out-of- treatment PWID. Participants were recruited mostly in harm reduction programs, completed an interviewer-administered questionnaire, provided a sample of gingival exudate for HIV and HCV antibody testing and were identified using an encrypted code allowing identification of multiple participations. Time trends were examined for HIV and HCV seroincidence, selected characteristics and behaviours. Cox proportional hazard regression was used to examine factors associated to HIV and HCV seroincidence. RESULTS: Between January 1995 and March 2020, 15,907 individuals have completed 31,051 questionnaires. HIV seroincidence decreased significantly from 5.0 per 100 person-years (p-y) in 1995 to 0.4 per 100 p-y in 2018. HCV seroincidence also decreased significantly between 1998 and 2011. The use of syringes already used by someone else decreased significantly, from 43.4 % in 1995 to 12.4 % in 2019, as well as the use of equipment other than syringe already used by someone else. Cocaine/crack injection decreased significantly while "opioids other than heroin" injection increased, concomitant to daily injection. Injection with syringes already used by someone else and cocaine as the most often injected drug were significantly associated with HIV seroincidence (1995-2020). Injected opioid other than heroin, injected cocaine/crack, injected 100 or more times in the past month, injected for less than 3 years, injected with syringes or equipment already used by someone else, injected with someone else and reported client sex partners were significantly associated with HCV seroincidence (2004-2020). CONCLUSION: HIV seroincidence and syringe/equipment sharing behaviour trends are encouraging, but HCV seroincidence remains high.

Changes in supervised consumption site use and emergency interventions in Montréal, Canada in the first twelve months of the COVID-19 pandemic: An interrupted time series study.

BACKGROUND: The COVID-19 pandemic has impacted supervised consumption site (SCS) operations in Montréal, Canada, potentially including changes in SCS visits, on-site emergency interventions, injection of specific drugs, and distribution of harm reduction materials. METHOD: We used administrative data from all four Montréal SCS from 1 March 2018 - 28 February 2021 to conduct an interrupted time series study with 13 March 2020 as the intervention point. We employed segmented regression using generalised least squares fit by maximum likelihood. We analysed monthly SCS visits and materials distributed as counts, and emergency interventions and drugs injected as proportions of visits. RESULTS: SCS visits (level change = -1,286; 95% CI [-1,642, -931]) and the proportion of visits requiring emergency intervention (level = -0.27% [-0.47%, -0.06%]) decreased immediately in March 2020, followed by an increasing trend in emergency interventions (slope change = 0.12% [0.10%, 0.14%]) over the ensuing 12 months. Over the same period, the proportion of injections involving opioids increased (slope = 0.05% [0.03%, 0.07%]), driven by increasing pharmaceutical opioid and novel synthetic opioid injections. Novel synthetic opioids were the drugs most often injected prior to overdose. The proportion of injections involving unregulated amphetamines increased immediately (level = 7.83% [2.93%, 12.73%]), then decreased over the next 12 months (slope = -1.86% [-2.51%, -1.21%]). There was an immediate increase in needle/syringe distribution (level = 16,552.81 [2,373, 30,732]), followed by a decreasing trend (slope = -2,398 [-4,218, -578]). There were no changes in pre-existing increasing trends in naloxone or fentanyl test strip distribution. CONCLUSION: Reduced SCS use and increasing emergency interventions at SCS are cause for serious concern. Findings suggest increased availability of novel synthetic opioids in Montréal, heightening overdose risk.

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 PWID's 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.

The need for treatment scale-up to impact HCV transmission in people who inject drugs in Montréal, Canada: a modelling study.

BACKGROUND: HCV transmission remains high in people who inject drugs (PWID) in Montréal. New direct-acting antivirals (DAAs), highly effective and more tolerable than previous regimens, make a "Treatment as Prevention" (TasP) strategy more feasible. This study assesses how improvements in the cascade of care could impact hepatitis C burden among PWID in Montréal. METHODS: We used a dynamic model to simulate HCV incidence and prevalence after 10 years, and cirrhosis complications after 10 and 40 years. Eight scenarios of improved cascade of care were examined. RESULTS: Using a baseline incidence and prevalence of 22.1/100 person-years (PY) and 53.1%, implementing the current cascade of care using DAAs would lead to HCV incidence and prevalence estimates at 10 years of 9.4/100PY and 55.8%, respectively. Increasing the treatment initiation rate from 5%/year initially to 20%/year resulted in large decreases in incidence (6.4/100PY), prevalence (36.6%), and cirrhosis complications (-18%/-37% after 10/40 years). When restricting treatment to fibrosis level ≥ F2 instead of F0 (reference scenario), such decreases in HCV occurrence were unreachable. Improving the whole cascade of care led to the greatest effect by halving both the incidence and prevalence at 10 years, and the number of cirrhosis complications after 40 years. CONCLUSIONS: The current level of treatment access in Montréal is limiting a massive decrease in hepatitis C burden among PWID. A substantial treatment scale-up, regardless of fibrosis level, is necessary. While improving the rest of the cascade of care is necessary to optimize a TasP strategy and control the HCV epidemic, a treatment scale-up is first needed.

Sex Work as an Emerging Risk Factor for Human Immunodeficiency Virus Seroconversion Among People who Inject Drugs in the SurvUDI Network.

BACKGROUND: Recent analyses have shown an emerging positive association between sex work and human immunodeficiency virus (HIV) incidence among people who inject drugs (PWIDs) in the SurvUDI network. METHODS: Participants who had injected in the past 6 months were recruited across the Province of Quebec and in the city of Ottawa, mainly in harm reduction programs. They completed a questionnaire and provided gingival exudate for HIV antibody testing. The associations with HIV seroconversion were tested with a Cox proportional hazard model using time-dependent covariables including the main variable of interest, sexual activity (sex work; no sex work; sexually inactive). The final model included significant variables and confounders of the associations with sexual activity. RESULTS: Seventy-two HIV seroconversions were observed during 5239.2 person-years (py) of follow-up (incidence rates: total = 1.4/100 py; 95% confidence interval [CI], 1.1-1.7; sex work = 2.5/100 py; 95% CI, 1.5-3.6; no sex work = 0.8/100 py; 95% CI, 0.5-1.2; sexually inactive = 1.8/100 py; 95% CI, 1.1-2.5). In the final multivariate model, HIV incidence was significantly associated with sexual activity (sex work: adjusted hazard ratio [AHR], 2.19; 95% CI, 1.13-4.25; sexually inactive: AHR, 1.62; 95% CI, 0.92-2.88), and injection with a needle/syringe used by someone else (AHR, 2.84; 95% CI, 1.73-4.66). CONCLUSIONS: Sex work is independently associated with HIV incidence among PWIDs. At the other end of the spectrum of sexual activity, sexually inactive PWIDs have a higher HIV incidence rate, likely due to more profound dependence leading to increased vulnerabilities, which may include mental illness, poverty, and social exclusion. Further studies are needed to understand whether the association between sex work and HIV is related to sexual transmission or other vulnerability factors.

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.

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.

Low perceived benefits and self-efficacy are associated with hepatitis C virus (HCV) infection-related risk among injection drug users.

Hepatitis C prevention counselling and education are intended to increase knowledge of disease, clarify perceptions about vulnerability to infection, and increase personal capacity for undertaking safer behaviours. This study examined the association of drug equipment sharing with psychosocial constructs of the AIDS Risk Reduction Model, specifically, knowledge and perceptions related to hepatitis C virus (HCV) among injection drug users (IDUs). Active IDUs were recruited between April 2004 and January 2005 from syringe exchange and methadone maintenance treatment programs in Montreal, Canada. A structured, interviewer-administered questionnaire elicited information on drug preparation and injection practices, self-reported hepatitis C testing and infection status, and AIDS Risk Reduction Model constructs. Separate logistic regression models were developed to examine variables in relation to: (1) the sharing of syringes, and (2) the sharing of drug preparation equipment (drug containers, filters, and water). Among the 321 participants, the mean age was 33 years, 70% were male, 80% were single, and 91% self-identified as Caucasian. In the multivariable analyses, psychosocial factors linked to syringe sharing were lower perceived benefits of safer injecting and greater difficulty to inject safely. As with syringe sharing, the sharing of drug preparation equipment was associated with lower perceived benefits of safer injecting but also with low self-efficacy to convince others to inject more safely. Interventions should aim to heighten awareness of the benefits of risk reduction and provide IDUs with the skills necessary to negotiate safer injecting with their peers.

Minimal uptake of sterile drug preparation equipment in a predominantly cocaine injecting population: implications for HIV and hepatitis C prevention.

OBJECTIVE: To identify factors associated with using sterile drug injection equipment by injection drug users (IDUs). METHODS: 275 IDUs were recruited from syringe exchange programs in Montreal, Canada in 2004-2005. A structured, interviewer-administered questionnaire collected information about demographics, drug injection practices, self-reported HIV and hepatitis C virus (HCV) status, and harm reduction behaviours. Logistic regression was used to model variables in relation to the use of sterile syringes, containers, filters, and drug preparation water. RESULTS: Sterile syringes, containers, filters, and water were used for at least half of injecting episodes by 95%, 23%, 23%, and 75% of subjects, respectively. In multivariate analysis, users of sterile syringes had higher odds of being older and injecting alone, and were less likely to report problems obtaining sterile syringes and requiring or providing help with injecting. Using sterile filters was associated with having at least high school education, injecting heroin, and injecting alone. In addition to the factors associated with filters, users of sterile containers were more likely to be HCV-negative and older. Using sterile water was associated with daily injecting and being HCV-negative. CONCLUSIONS: Improving the uptake of sterile drug preparation equipment among IDUs could be aided by considering drug-specific risks, such as drug of choice and injecting context, while reinforcing existing messages on safer injecting. The association between sterile equipment use and HCV-negative status may be representative of an established subgroup of safer injectors who have remained free of infection because of consistent safe injecting practices.