Women Who Use Drugs and Have Sex with Women in a Canadian Setting: Barriers to Treatment Enrollment and Exposure to Violence and Homelessness.

Individuals who use illicit drugs and belong to a sexual minority group often contend with elevated risks for adverse health outcomes. However, little is known about women who use drugs and have sex with women. We therefore sought to identify sociodemographic, substance use patterns, and exposures to social-structural factors associated with reporting sexual activity among women participating in three open prospective cohort studies of individuals who use illicit drugs in Vancouver, Canada. Generalized estimating equations were used to identify substance use patterns, violence, and other social and structural drivers of health-related harm among women who reported having sex with women (WSW) between December 2005 and May 2012. In multivariate analyses, younger age (adjusted odds ratio [AOR] 2.89; 95 % confidence interval [CI] 1.81, 4.60), violence (AOR 1.78; 95 % CI 1.22, 2.59), and homelessness (AOR 1.42; 95 % CI 1.00, 2.02) were associated with WSW. WSW were also less likely to report enrollment in addiction treatment (AOR 0.68; 95 % CI 0.46, 0.99). In a second model, sexual violence (AOR 3.47; 95 % CI 2.08, 5.78) in the previous 6 months was also found to be positively associated with WSW. These findings indicate a critical need for more thorough understandings of the intersections between sexual relationships, exposure to violence, and enrollment in addiction treatment among women who use illicit drugs, as well as the development of programs to address the unique needs of this population.

High-intensity cannabis use and adherence to antiretroviral therapy among people who use illicit drugs in a Canadian setting.

Cannabis is increasingly prescribed clinically and utilized by people living with HIV/AIDS (PLWHA) to address symptoms of HIV disease and to manage side effects of antiretroviral therapy (ART). In light of concerns about the possibly deleterious effect of psychoactive drug use on adherence to ART, we sought to determine the relationship between high-intensity cannabis use and adherence to ART among a community-recruited cohort of HIV-positive illicit drug users. We used data from the ACCESS study, an ongoing prospective cohort study of HIV-seropositive illicit drug users linked to comprehensive ART dispensation records in a setting of universal no-cost HIV care. We estimated the relationship between at least daily cannabis use in the last 6 months, measured longitudinally, and the likelihood of optimal adherence to ART during the same period, using a multivariate linear mixed-effects model accounting for relevant socio-demographic, behavioral, clinical and structural factors. From May 2005 to May 2012, 523 HIV-positive illicit drug users were recruited and contributed 2,430 interviews. At baseline, 121 (23.1 %) participants reported at least daily cannabis use. In bivariate and multivariate analyses we did not observe an association between using cannabis at least daily and optimal adherence to prescribed HAART (Adjusted Odds Ratio = 1.12, 95 % Confidence Interval [95 % CI]: 0.76-1.64, p value = 0.555.) High-intensity cannabis use was not associated with adherence to ART. These findings suggest cannabis may be utilized by PLWHA for medicinal and recreational purposes without compromising effective adherence to ART.

Suboptimal plasma HIV-1 RNA suppression and adherence among sex workers who use illicit drugs in a Canadian setting: an observational cohort study.

OBJECTIVE: Studies have demonstrated the central function of plasma HIV-1 RNA viral load (pVL) levels on determining the risk of HIV disease progression and transmission. However, there is limited empirical research on virologic outcomes among sex workers who use illicit drugs (SW-DU). METHODS: Data were derived from the AIDS Care Cohort to evaluate Exposure to Survival Services, a cohort of HIV-positive illicit drug users. Using generalised estimating equations, we studied the longitudinal relationship between sex work and pVL suppression. We also tested whether adherence to antiretroviral therapy (ART) mediated the relationship between sex work and pVL suppression. RESULTS: Between May 1996 and May 2012, 587 ART-exposed participants (2224 person-years of observation) were included in the study, among whom 127 (21.6%) reported sex work. In a time-updated multivariate model adjusted for various demographic, socioeconomic and clinical confounders (eg, gender, incarceration, CD4 cell count), SW-DU had an independently reduced odds of pVL suppression compared to non-SW-DU (adjusted OR (AOR)=0.66; 95% CI 0.45 to 0.96). However, adding ART adherence to the multivariate model eliminated this association (p>0.05), suggesting adherence mediated the relationship between sex work and pVL suppression. CONCLUSIONS: Evidence-based interventions to improve adherence to ART among SW-DU are urgently needed to help produce the maximum HIV treatment and prevention benefit of ART among this highly vulnerable population.

Health and social harms associated with crystal methamphetamine use among street-involved youth in a Canadian setting.

BACKGROUND AND OBJECTIVES: Despite recent increases in crystal methamphetamine use among high-risk populations such as street-involved youth, few prospective studies have examined the health and social outcomes associated with active crystal methamphetamine use. METHODS: We enrolled 1,019 street-involved youth in Vancouver, Canada, in a prospective cohort known as the at-risk youth study (ARYS). Participants were assessed semi-annually and a generalized estimating equation (GEE) logistic regression was used to identify factors independently associated with active crystal methamphetamine use. RESULTS: Among 1,019 participants recruited into ARYS between 2005 and 2012 the median follow up duration was 17 months, 320 (31.4%) participants were female and 454 (44.6%) had previously used crystal methamphetamine at baseline. In adjusted GEE analyses, active crystal methamphetamine use was independently associated with Caucasian ethnicity (adjusted odds ratio [AOR] = 1.37; 95% confidence interval [CI]: 1.04-1.81), homelessness (AOR = 1.34; 95% CI: 1.15-1.56), injection drug use (AOR = 3.40; 95% CI: 2.76-4.19), non-fatal overdose (AOR = 1.46; 95%CI: 1.07-2.00), being a victim of violence (AOR = 1.19; 95% CI: 1.02-1.38), involvement in sex work (AOR = 1.39; 95% CI: 1.03-1.86), and drug dealing (AOR = 1.60; 95% CI: 1.35-1.90). DISCUSSION AND CONCLUSIONS: Prevalence of crystal methamphetamine use was high in this setting and active use was independently associated with a range of serious health and social harms. SCIENTIFIC SIGNIFICANCE: Evidence-based strategies to prevent and treat crystal methamphetamine use are urgently needed.

Crystal methamphetamine initiation among street-involved youth.

BACKGROUND: Although many settings have recently documented a substantial increase in the use of methamphetamine-type stimulants, recent reviews have underscored the dearth of prospective studies that have examined risk factors associated with the initiation of crystal methamphetamine use. OBJECTIVES: Our objectives were to examine rates and risk factors for the initiation of crystal methamphetamine use in a cohort of street-involved youth. METHODS: Street-involved youth in Vancouver, Canada, were enrolled in a prospective cohort known as the At-Risk Youth Study (ARYS). A total of 205 crystal methamphetamine-naïve participants were assessed semi-annually and Cox regression analyses were used to identify factors independently associated with the initiation of crystal methamphetamine use. RESULTS: Among 205 youth prospectively followed from 2005 to 2012, the incidence density of crystal methamphetamine initiation was 12.2 per 100 person years. In Cox regression analyses, initiation of crystal methamphetamine use was independently associated with previous crack cocaine use (adjusted relative hazard [ARH] = 2.24 [95% CI: 1.20-4.20]) and recent drug dealing (ARH = 1.98 [95% CI: 1.05-3.71]). Those initiating methamphetamine were also more likely to report a recent nonfatal overdose (ARH = 3.63 [95% CI: 1.65-7.98]) and to be male (ARH = 2.12 [95% CI: 1.06-4.25]). CONCLUSIONS: We identified high rates of crystal methamphetamine initiation among this population. Males those involved in the drug trade, and those who used crack cocaine were more likely to initiate crystal methamphetamine use. Evidence-based strategies to prevent and treat crystal methamphetamine use are urgently needed.

Policing the epidemic: High burden of workplace violence among female sex workers in conflict-affected northern Uganda.

Sex workers in sub-Saharan Africa experience a high burden of HIV with a paucity of data on violence and links to HIV risk among sex workers, and even less within conflict-affected environments. Data are from a cross-sectional survey of female sex workers in Gulu, northern Uganda (n = 400). Logistic regression was used to determine the specific association between policing and recent physical/sexual violence from clients. A total of 196 (49.0%) sex workers experienced physical/sexual violence by a client. From those who experienced client violence the most common forms included physical assault (58.7%), rape (38.3%), and gang rape (15.8%) Police harassment was very common, a total of 149 (37.3%) reported rushing negotiations with clients because of police presence, a practice that was significantly associated with increased odds of client violence (adjusted odds ratio: 1.61, 95% confidence intervals: 1.03-2.52). Inconsistent condom use with clients, servicing clients in a bar, and working for a manager/pimp were also independently associated with recent client violence. Structural and community-led responses, including decriminalisation, and engagement with police and policy stakeholders, remain critical to addressing violence, both a human rights and public health imperative.

The 'stolen generations' of mothers and daughters: child apprehension and enhanced HIV vulnerabilities for sex workers of Aboriginal ancestry.

OBJECTIVES: The number of children in care of the state continues to grow in BC, Canada with a historical legacy of child apprehension among criminalized and marginalized populations, particularly women of Aboriginal ancestry and sex workers. However, there is a paucity of research investigating child apprehension experiences among marginalized mothers. The objective of the current analysis is to examine the prevalence and correlates of child apprehensions among female sex workers in Vancouver, Canada. METHODS: Analyses were drawn from the AESHA (An Evaluation of Sex Workers Health Access, 2010-present), a prospective cohort of street and off-street SWs, through outreach and semi-annual visits to the research office. Bivariate and multivariate logistic regression were used to examine correlates of child apprehension. RESULTS: Of a total of 510 SWs, 350 women who had given birth to at least one child were included in the analyses (median age = 37 yrs: IQR: 31-44 yrs). The prevalence of child apprehension among mothers was 38.3%, with 37.4% reporting having been apprehended themselves by child welfare services. In multivariable analysis, servicing clients in outdoor public spaces (versus formal sex work establishments or informal indoor settings) (adjusted odds ratio, (aOR) = 2.73; 95%CI 1.27-5.90), history of injecting drugs (aOR  = 2.53; 95%CI 1.42-4.49), Aboriginal ancestry (aOR = 1.66; 95%CI 1.01-2.74) were associated with increased odds of child apprehension. DISCUSSION/CONCLUSIONS: Child apprehension rates are high, particularly among the most marginalized sex workers, including sex workers who use drugs and sex workers of Aboriginal ancestry. Structural reforms to child protection are urgently needed, that support family-based care address the historical legacy of colonization affecting Aboriginal peoples.

Use of a medically supervised injection facility among street youth.

PURPOSE: Supervised injecting facilities (SIFs) provide a sanctioned space for injection drug users and are associated with decreased overdose mortality and HIV risk behaviors among adults. Little is known about SIF use among youth. We identified factors associated with use of the Vancouver SIF, the only such facility in North America, among street youth. METHODS: From September 2005 to May 2012, we collected data from the At-Risk Youth Study, a prospective cohort of street youth in Vancouver, BC, Canada. Eligible youth were aged 14-26 years. Participants reporting injection completed questionnaires at baseline and semiannually. We used generalized estimating equation logistic regression to identify factors associated with SIF use. RESULTS: During the study period, 42.3% of 414 injecting youth reported use of the SIF at least once. Of all SIF-using youth, 51.4% went to the facility at least weekly, and 44.5% used it for at least one-quarter of all injections. SIF-using youth were more likely to live or spend time in the neighborhood surrounding the SIF (adjusted odds ratio [AOR], 3.29; 95% confidence interval [CI], 2.38-4.54), to inject in public (AOR, 2.08; 95% CI, 1.53-2.84), or to engage in daily injection of heroin (AOR, 2.36; 95% CI, 1.72-3.24), cocaine (AOR, 2.44; 95% CI, 1.34-4.45), or crystal methamphetamine (AOR, 1.62; 95% CI, 1.13-2.31). CONCLUSIONS: This study, the first to examine SIF use among street youth in North America, demonstrated that the facility attracted high-frequency young drug users most at risk of blood-borne infection and overdose and those who otherwise inject in public spaces.

High prevalence and partner correlates of physical and sexual violence by intimate partners among street and off-street sex workers.

OBJECTIVES: Intimate partner violence (IPV) is associated with increased risk of HIV among women globally. There is limited evidence and understanding about IPV and potential HIV risk pathways among sex workers (SWs). This study aims to longitudinally evaluate prevalence and correlates of IPV among street and off-street SWs over two-years follow-up. METHODS: Longitudinal data were drawn from an open prospective cohort, AESHA (An Evaluation of Sex Workers Health Access) in Metro Vancouver, Canada (2010-2012). Prevalence of physical and sexual IPV was measured using the WHO standardized IPV scale (version 9.9). Bivariate and multivariable logistic regression using Generalized Estimating Equations (GEE) were used to examine interpersonal and structural correlates of IPV over two years. RESULTS: At baseline, 387 SWs had a male, intimate sexual partner and were eligible for this analysis. One-fifth (n = 83, 21.5%) experienced recent physical/sexual IPV at baseline and 26.2% over two-years follow-up. In multivariable GEE analysis, factors independently correlated with physical/sexual IPV in the last six months include: childhood (<18 years) sexual/physical abuse (adjusted odds ratio [AOR] = 2.05, 95% confidence interval [CI]: 1.14-3.69), inconsistent condom use for vaginal and/or anal sex with intimate partner (AOR = 1.84, 95% CI: 1.07-3.16),

Early sex work initiation independently elevates odds of HIV infection and police arrest among adult sex workers in a Canadian setting.

OBJECTIVES: To explore factors associated with early sex work initiation and model the independent effect of early initiation on HIV infection and prostitution arrests among adult sex workers (SWs). DESIGN: Baseline data (2010-2011) were drawn from a cohort of SWs who exchanged sex for money within the last month and were recruited through time location sampling in Vancouver, Canada. Analyses were restricted to adults ≥18 years old. METHODS: SWs completed a questionnaire and HIV/sexually transmitted infection testing. Using multivariate logistic regression, we identified associations with early sex work initiation (<18 years old) and constructed confounder models examining the independent effect of early initiation on HIV and prostitution arrests among adult SWs. RESULTS: Of 508 SWs, 193 (38.0%) reported early sex work initiation, with 78.53% primarily street-involved SWs and 21.46% off-street SWs. HIV prevalence was 11.22%, which was 19.69% among early initiates. Early initiates were more likely to be Canadian born [adjusted odds ratio (AOR): 6.8, 95% confidence interval (CI): 2.42 to 19.02], inject drugs (AOR: 1.6, 95% CI: 1.0 to 2.5), and to have worked for a manager (AOR: 2.22, 95% CI: 1.3 to 3.6) or been coerced into sex work (AOR: 2.3, 95% CI: 1.14 to 4.44). Early initiation retained an independent effect on increased risk of HIV infection (AOR: 2.5, 95% CI: 1.3 to 3.2) and prostitution arrests (AOR: 2.0, 95% CI: 1.3 to 3.2). CONCLUSIONS: Adolescent sex work initiation is concentrated among marginalized, drug, and street-involved SWs. Early initiation holds an independent increased effect on HIV infection and criminalization of adult SWs. Findings suggest the need for evidence-based approaches to reduce harm among adult and youth SWs.

Declining incidence of hepatitis C virus infection among people who inject drugs in a Canadian setting, 1996-2012.

BACKGROUND: People who inject drugs (PWID) are at high risk of hepatitis C virus (HCV) infection. Trends in HCV incidence and associated risk factors among PWID recruited between 1996 and 2012 in Vancouver, Canada were evaluated. METHODS: Data were derived from a long-term cohort of PWID in Vancouver. Trends in HCV incidence were evaluated. Factors associated with time to HCV infection were assessed using Cox proportional hazards regression. RESULTS: Among 2,589, 82% (n = 2,121) were HCV antibody-positive at enrollment. Among 364 HCV antibody-negative participants with recent (last 30 days) injecting at enrollment, 126 HCV seroconversions were observed [Overall HCV incidence density: 8.6 cases/100 person-years (py); 95% confidence interval (95% CI): 7.2, 10.1; HCV incidence density among those with injecting during follow-up: 11.5 cases/100 py; 95% CI 9.7, 13.6]. The overall HCV incidence density declined significantly from 25.0/100 py (95% CI: 20.2, 30.3) in 1996-99, as compared to 6.0/100 py (95% CI: 4.1, 8.5) in 2000-2005, and 3.1/100 py (95% CI: 2.0, 4.8) in 2006-2012. Among those with injecting during follow-up, the overall HCV incidence density declined significantly from 27.9/100 py (95% CI: 22.6, 33.6) in 1996-99, as compared to 7.5/100 py (95% CI: 5.1, 10.6) in 2000-2005, and 4.9/100 py (95% CI: 3.1, 7.4) in 2006-2012. Unstable housing, HIV infection, and injecting of cocaine, heroin and methamphetamine were independently associated with HCV seroconversion. CONCLUSIONS: HCV incidence has dramatically declined among PWID in this setting. However, improved public health strategies to prevent and treat HCV are urgently required to reduce HCV-associated morbidity and mortality.

Risk factors for progression to regular injection drug use among street-involved youth in a Canadian setting.

BACKGROUND: Street-involved youth are at high risk for experimenting with injection drug use; however, little attention has been given to identifying the factors that predict progression to on-going injecting. METHODS: Logistic regression was used to identify factors associated with progression to injecting weekly on a regular basis among a Canadian cohort of street-involved youth. RESULTS: Among our sample of 405 youth who had initiated injecting at baseline or during study observation, the median age was 22 years (interquartile range [IQR]=21-24), and 72% (293) reported becoming a regular injector at some point after their first injection experience. Of these, the majority (n=186, 63%) reported doing so within a month of initiating injection drug use. In multivariate analysis, the drug used at the first injection initiation event (opiates vs. cocaine vs. methamphetamine vs. other; all p>0.05) was not associated with progression; however, younger age at first injection (adjusted odds ratio [AOR]=1.13), a history of childhood physical abuse (AOR=1.81), prior regular use of the drug first injected (AOR=1.77), and having a sexual partner present at the first injection event (AOR=2.65) independently predicted progression to regular injecting. CONCLUSION: These data highlight how quickly youth progress to become regular injectors after experimentation. Findings indicate that addressing childhood trauma and interventions such as evidence-based youth focused addiction treatment that could prevent or delay regular non-injection drug use, may reduce progression to regular injection drug use among this population.

CrypticIBDcheck: an R package for checking cryptic relatedness in nominally unrelated individuals.

BACKGROUND: In population association studies, standard methods of statistical inference assume that study subjects are independent samples. In genetic association studies, it is therefore of interest to diagnose undocumented close relationships in nominally unrelated study samples. RESULTS: We describe the R package CrypticIBDcheck to identify pairs of closely-related subjects based on genetic marker data from single-nucleotide polymorphisms (SNPs). The package is able to accommodate SNPs in linkage disequibrium (LD), without the need to thin the markers so that they are approximately independent in the population. Sample pairs are identified by superposing their estimated identity-by-descent (IBD) coefficients on plots of IBD coefficients for pairs of simulated subjects from one of several common close relationships. CONCLUSIONS: The methods implemented in CrypticIBDcheck are particularly relevant to candidate-gene association studies, in which dependent SNPs cluster in a relatively small number of genes spread throughout the genome. The accommodation of LD allows the use of all available genetic data, a desirable property when working with a modest number of dependent SNPs within candidate genes. CrypticIBDcheck is available from the Comprehensive R Archive Network (CRAN).