Jo-Anne Stoltz

Evaluating methamphetamine use and risks of injection initiation among street youth: the ARYS study

Many Canadian cities are experiencing ongoing infectious disease and overdose epidemics among injection drug users (IDU). These health concerns have recently been exacerbated by the increasing availability and use of methamphetamine. The challenges of reducing health-related harms among IDU have led to an increased recognition that strategies to prevent initiation into injection drug use must receive renewed focus. In an effort to better explore the factors that may protect against or facilitate entry into injection drug use, the At Risk Youth Study (ARYS) has recently been initiated in Vancouver, Canada. The local setting is unique due to the significant infrastructure that has been put in place to reduce HIV transmission among active IDU. The ARYS study will seek to examine the impact of these programs, if any, on non-injection drug users. In addition, Vancouver has been the site of widespread use of methamphetamine in general and has seen a substantial increase in the use of crystal methamphetamine among street youth. Hence, the ARYS cohort is well positioned to examine the harms associated with methamphetamine use, including its potential role in facilitating initiation into injection drug use. This paper provides some background on the epidemiology of illicit drug use among street youth in North America and outlines the methodology of ARYS, a prospective cohort study of street youth in Vancouver, Canada.

Childhood trauma and injection drug use among high-risk youth.

We examined the association between five types of childhood maltreatment and initiation of injection drug use among a cohort of high-risk youth in Vancouver, Canada. Among 560 participants, 230 (41.1%) had injected drugs previously. In multivariate logistic analyses, only physical abuse (adjusted odds ratio = 1.91, 95% confidence interval: 1.29-2.83) was associated with injection drug use. These findings highlight the impact of childhood physical abuse on subsequent initiation into injection drug use among high-risk youth.

Sex trade involvement is associated with elevated HIV incidence among injection drug users in Vancouver

Background: Canadas prostitution laws are under scrutiny, and there has been growing debate about the optimal strategies for reducing the harms associated with prostitution. Methods: We evaluated whether sex trade involvement was associated with elevated HIV incidence in a cohort of injection drug users. HIV incidence rates were calculated using Kaplan-Meier methods and Cox proportional hazards regression. Results: At 48 months after enrolment, the rate of HIV was 11.7% among those who did not report baseline sex trade involvement compared to 16.7% among those who did (p = 0.049). The elevated HIV infection rate associated with sex trade involvement was also observed in a Cox model that considered sex trade involvement as a time-updated covariate (relative hazard = 1.51 [95% CI: 1.02–2.25]). Interpretation: These findings should be useful to those currently considering the optimal legal framework for addressing the community and health related harms associated with prostitution in Canada.

The impact of sex partners' HIV status on HIV seroconversion in a prospective cohort of injection drug users.

Objective and Design:The identification of individuals at highest risk of HIV infection is critical for targeting prevention strategies. We evaluated the HIV status of the sex partners of injection drug users (IDUs) and rates of subsequent HIV seroconversion among a prospective cohort study of IDUs. Methods:We performed an analysis of the time to HIV infection among baseline HIV-negative IDUs enrolled in the Vancouver Injection Drug Users Study. IDUs were stratified based on whether or not they reported having an HIV-positive sex partner. Kaplan-Meier methods were used to estimate cumulative HIV incidence rates, and Cox regression was used to determine adjusted relative hazards (RHs) for HIV seroconversion. Results:Of 1013 initially HIV-negative IDUs, 4.8% had an HIV-positive partner at baseline. After 18 months, the cumulative HIV incidence rate was significantly elevated among those who reported having an HIV-positive sex partner (23.4% vs. 8.1%; log-rank P < 0.001). In a Cox regression model adjusting for all variables that were associated with the time to HIV infection in univariate analyses, including drug use characteristics, having an HIV-positive sex partner (RH = 2.42 [95% confidence interval: 1.30 to 4.60]; P = 0.005) remained independently associated with time to HIV seroconversion. Conclusions:Having an HIV-positive sex partner was strongly and independently associated with seroconversion after adjustment for risk factors related to drug use. Our findings may aid public health workers in their efforts to identify IDUs who should be targeted with education and prevention efforts and indicate the need for ongoing development of prevention interventions for IDU sex partners who are HIV discordant.

Characteristics of young illicit drug injectors who use North America's first medically supervised safer injecting facility

The study examined whether North Americas first medically supervised safer injection facility (SIF) attracts young injection drug users (IDUs) who are at high risk of health-related harm. Prevalence of SIF use was determined based on data obtained after the SIFs opening. Predictors of initiating future SIF use were determined based on behavioral information obtained from the participants study visit immediately preceding the SIFs opening. The median duration between the acquisition of pre-SIF opening behavioral data and the more recent interview, where SIF use was measured, was 16 months. Characteristics of IDUs who did and did not subsequently initiate SIF use were statistically compared (N = 135). Data from the 6-month period prior to the SIFs opening showed that youth initiating SIF use were significantly more likely to have been in jail, to use heroin daily, to have overdosed, to have binged on drugs, to have loaned needles, and to have been homeless. The study suggests that among IDUs 29 years of age or younger, those who used the SIF were at higher risk than those who were not.