Changes in drug use behaviors coinciding with the emergence of illicit fentanyl among people who use drugs in Vancouver, Canada

Background: With the emergence of illicitly-manufactured fentanyl, drug overdose deaths have risen in unprecedented numbers. In this context, there is an urgent need to characterize potential changes in drug use behaviors among people who use drugs (PWUD). Objective: To examine changes in drug use behaviors following the emergence of illicit fentanyl among people who use drugs (PWUD). Methods: Data for this cross-sectional analysis was derived from three prospective cohorts of PWUD between December 2016 and May 2017 in Vancouver, Canada. Multivariable logistic regression was used to determine factors associated with self-reported behavior changes (binary variable "yes" or "no") following the emergence of illicit fentanyl. Results: Among 999 participants [363 (36.3%) females], 388 (38.8%) reported some behavior change. The remaining 611 (61.2%) reported no change in behavior; 240 (39.3%) of these individuals had recently been exposed to fentanyl. In multivariable analyses, factors independently associated with behavior change included recent non-fatal overdose (Adjusted Odds Ratio [AOR] = 2.28), active injection drug use (AOR = 1.96), being on opioid agonist therapy (AOR = 1.80), and urine drug screen positive for fentanyl (AOR = 1.45), (all p < .05). Conclusion: The majority of PWUD in our sample did not change their drug use behavior despite a high prevalence of fentanyl exposure, indicating a need for targeted behavior change messaging and overdose prevention efforts such as naloxone and addiction treatment for this sub-population of PWUD. Further, the high fentanyl exposure observed in our sample suggests a need to address upstream structural factors shaping the overdose risk in addition to individual behavioral change.

The effect of engagement in an HIV/AIDS integrated health programme on plasma HIV-1 RNA suppression among HIV-positive people who use illicit drugs: a marginal structural modelling analysis

OBJECTIVES

HIV treatment-as-prevention campaigns emphasize early diagnosis and immediate access to care and antiretroviral therapy for HIV-positive individuals in order to increase levels of plasma HIV RNA viral load (VL) suppression. However, the possible role of harm reduction-based programmes in this objective has not yet been well evaluated. The objective of the study was to examine the relationship between being a client of the Dr. Peter Centre (DPC; an HIV/AIDS-focused adult integrated health programme) and VL suppression among highly active antiretroviral therapy (HAART)-exposed HIV-positive people who use illicit drugs (PWUD) in Vancouver, Canada.

METHODS

Data were derived from the AIDS Care Cohort to Evaluate Exposure to Survival Services (ACCESS) study, a study of a community-recruited cohort of HIV-positive PWUD. A marginal structural model using inverse probability of treatment weights was used to estimate the longitudinal relationship between being a DPC client and exhibiting a VL < 50 HIV-1 RNA copies/mL plasma.

RESULTS

Between 2005 and 2014, 746 HAART-exposed participants were included in the study, of whom 269 (36.1%) reported being a DPC client at some time during the study period. A marginal structural model estimated a 1.54 greater odds of achieving VL suppression (95% confidence interval 1.20-1.99) among DPC clients.

CONCLUSIONS

Our findings demonstrate that participating in an innovative HIV/AIDS-focused adult integrated health programme that provides a broad range of clinical, harm reduction, and support services may contribute to optimizing the benefits of HAART in terms of morbidity, mortality and viral transmission among PWUD, and as a result help to fulfill the goals of the treatment-as-prevention strategy.

Healthcare avoidance by people who inject drugs in Bangkok, Thailand

BACKGROUND

Although people who inject drugs (IDU) often contend with various health-related harms, timely access to health care among this population remains low. We sought to identify specific individual, social and structural factors constraining healthcare access among IDU in Bangkok, Thailand.

METHODS

Data were derived from a community-recruited sample of IDU participating in the Mitsampan Community Research Project between July and October 2011. We assessed the prevalence and correlates of healthcare avoidance due to one's drug use using multivariate logistic regression.

RESULTS

Among 437 participants, 112 (25.6%) reported avoiding health care because they were IDU. In multivariate analyses, factors independently associated with avoiding health care included having ever been drug tested by police [adjusted odds ratio (AOR) = 1.80], experienced verbal abuse (AOR = 3.15), been discouraged from engaging in usual family activities (AOR = 3.27), been refused medical care (AOR = 10.90), experienced any barriers to health care (AOR = 4.87) and received healthcare information and support at a drop-in centre (AOR = 1.92) (all P < 0.05).

CONCLUSIONS

These findings highlight the need to address the broader policy environment, which perpetuates the criminalization and stigmatization of IDU, and to expand peer-based interventions to facilitate access to health care for IDU in this setting.

Aboriginal street-involved youth experience elevated risk of incarceration

OBJECTIVES

Past research has identified risk factors associated with incarceration among adult Aboriginal populations; however, less is known about incarceration among street-involved Aboriginal youth. Therefore, we undertook this study to longitudinally investigate recent reports of incarceration among a prospective cohort of street-involved youth in Vancouver, Canada.

STUDY DESIGN

Prospective cohort study.

METHODS

Data were collected from a cohort of street-involved, drug-using youth from September 2005 to May 2013. Multivariate generalized estimating equation analyses were employed to examine the potential relationship between Aboriginal ancestry and recent incarceration.

RESULTS

Among our sample of 1050 youth, 248 (24%) reported being of aboriginal ancestry, and 378 (36%) reported being incarcerated in the previous six months at some point during the study period. In multivariate analysis controlling for a range of potential confounders including drug use patterns and other risk factors, Aboriginal ancestry remained significantly associated with recent incarceration (adjusted odds ratio [AOR] = 1.44; 95% confidence interval [CI]: 1.12-1.86).

CONCLUSIONS

Even after adjusting for drug use patterns and other risk factors associated with incarceration, this study found that Aboriginal street-involved youth were still significantly more likely to be incarcerated than their non-Aboriginal peers. Given the established harms associated with incarceration these findings underscore the pressing need for systematic reform including culturally appropriate interventions to prevent Aboriginal youth from becoming involved with the criminal justice system.

Characterizing longitudinal health state transitions among heroin, cocaine, and methamphetamine users

AIMS

Characterize longitudinal patterns of drug use careers and identify determinants of drug use frequency across cohorts of primary heroin, methamphetamine (MA) and cocaine users.

DESIGN

Pooled analysis of prospective cohort studies.

SETTINGS

Illicit drug users recruited from community, criminal justice and drug treatment settings in California, USA.

PARTICIPANTS

We used longitudinal data on from five observational cohort studies featuring primary users of heroin (N=629), cocaine (N=694) and methamphetamine (N=474). The mean duration of follow-up was 20.9 years.

MEASUREMENTS

Monthly longitudinal data was arranged according to five health states (incarceration, drug treatment, abstinence, non-daily and daily use). We fitted proportional hazards (PH) frailty models to determine independent differences in successive episode durations. We then executed multi-state Markov (MSM) models to estimate probabilities of transitioning between health states, and the determinants of these transitions.

FINDINGS

Across primary drug use types, PH frailty models demonstrated durations of daily use diminished in successive episodes over time. MSM models revealed primary stimulant users had more erratic longitudinal patterns of drug use, transitioning more rapidly between periods of treatment, abstinence, non-daily and daily use. MA users exhibited relatively longer durations of high-frequency use. Criminal engagement had a destabilizing effect on health state durations across drug types. Longer incarceration histories were associated with delayed transitions toward cessation.

CONCLUSIONS

PH frailty and MSM modeling techniques provided complementary information on longitudinal patterns of drug abuse. This information can inform clinical practice and policy, and otherwise be used in health economic simulation models, designed to inform resource allocation decisions.

Criminalisation of clients: reproducing vulnerabilities for violence and poor health among street-based sex workers in Canada-a qualitative study

OBJECTIVES

To explore how criminalisation and policing of sex buyers (clients) rather than sex workers shapes sex workers' working conditions and sexual transactions including risk of violence and HIV/sexually transmitted infections (STIs).

DESIGN

Qualitative and ethnographic study triangulated with sex work-related violence prevalence data and publicly available police statistics.

SETTING

Vancouver, Canada, provides a unique opportunity to evaluate the impact of policies that criminalise clients as the local police department adopted a sex work enforcement policy in January 2013 that prioritises sex workers' safety over arrest, while continuing to target clients.

PARTICIPANTS

26 cisgender and 5 transgender women who were street-based sex workers (n=31) participated in semistructured interviews about their working conditions. All had exchanged sex for money in the previous 30 days in Vancouver.

OUTCOME MEASURES

Thematic analysis of interview transcripts and ethnographic field notes focused on how police enforcement of clients shaped sex workers' working conditions and sexual transactions, including risk of violence and HIV/STIs, over an 11-month period postpolicy implementation (January-November 2013).

RESULTS

Sex workers' narratives and ethnographic observations indicated that while police sustained a high level of visibility, they eased charging or arresting sex workers and showed increased concern for their safety. However, participants' accounts and police statistics indicated continued police enforcement of clients. This profoundly impacted the safety strategies sex workers employed. Sex workers continued to mistrust police, had to rush screening clients and were displaced to outlying areas with increased risks of violence, including being forced to engage in unprotected sex.

CONCLUSIONS

These findings suggest that criminalisation and policing strategies that target clients reproduce the harms created by the criminalisation of sex work, in particular, vulnerability to violence and HIV/STIs. The current findings support decriminalisation of sex work to ensure work conditions that support the health and safety of sex workers in Canada and globally.

Methadone maintenance therapy decreases the rate of antiretroviral therapy discontinuation among HIV-positive illicit drug users

We sought to examine whether methadone maintenance therapy (MMT) decreased rates of antiretroviral therapy (ART) discontinuation and was associated with plasma HIV RNA responses among a cohort of illicit drug users. Cumulative ART discontinuation rates were estimated using Kaplan-Meier methods and factors independently associated with ART discontinuation were identified using Cox proportional hazards regression. Engagement in MMT was negatively and independently associated with ART discontinuation [Adjusted Relative Hazard = 0.67 (95 % CI 0.54-0.83); p < 0.001]. Among participants receiving ART and MMT, 81.6 % of plasma HIV-1 RNA assessments were <500 copies/mL, while 65.81 % of HIV-1 RNA assessments among those prescribed ART without MMT were <500 copies/mL (p < 0.001). These results demonstrate that engagement in MMT conferred a protective benefit against ART discontinuation and was associated with a significant increase in plasma HIV RNA suppression among HIV-infected opioid-dependent drug users.

Low rates of hepatitis C testing among people who inject drugs in Thailand: implications for peer-based interventions

BACKGROUND

Regular testing for hepatitis C virus (HCV) provides an opportunity for HCV prevention and treatment efforts. In Thailand, the barriers and facilitators of HCV testing among people who inject drugs (IDU) are not known.

METHODS

Using data derived from the Mitsampan Community Research Project between July and October 2011, we assessed the prevalence and factors associated with ever having been tested for HCV antibodies using bivariate statistics and multivariate logistic regression.

RESULTS

Among 427 participants, 141 (33.0%) reported a history of HCV antibody testing. In multivariate analyses, factors positively associated with receiving an HCV antibody test included higher than secondary education [adjusted odds ratio (AOR) = 2.20; 95% confidence interval (CI): 1.35-3.64], binge drug use (AOR = 1.81; 95% CI: 1.12-2.93), methadone treatment enrollment (AOR = 3.47; 95% CI: 1.85-6.95) and having received peer-based education on HCV (AOR = 4.22; 95% CI: 2.66-6.77).

CONCLUSIONS

We found one-third of Thai IDU in our sample reporting a history of HCV testing. The finding that IDU who received peer-based HCV education were more likely to access HCV testing provides evidence for the value of peer-based interventions for this population.

Improved adherence to modern antiretroviral therapy among HIV-infected injecting drug users

OBJECTIVES

Adherence to antiretroviral therapy (ART) among injecting drug users (IDUs) is often suboptimal, yet little is known about changes in patterns of adherence since the advent of highly active antiretroviral therapy in 1996. We sought to assess levels of optimal adherence to ART among IDUs in a setting of free and universal HIV care.

METHODS

Data were collected through a prospective cohort study of HIV-positive IDUs in Vancouver, British Columbia. We calculated the proportion of individuals achieving at least 95% adherence in the year following initiation of ART from 1996 to 2009.

RESULTS

Among 682 individuals who initiated ART, the median age was 37 years (interquartile range 31-44 years) and 248 participants (36.4%) were female. The proportion achieving at least 95% adherence increased over time, from 19.3% in 1996 to 65.9% in 2009 (Cochrane-Armitage test for trend: P < 0.001). In a logistic regression model examining factors associated with 95% adherence, initiation year was statistically significant (odds ratio 1.08; 95% confidence interval 1.03-1.13; P < 0.001 per year after 1996) after adjustment for a range of drug use variables and other potential confounders.

CONCLUSIONS

The proportion of IDUs achieving at least 95% adherence during the first year of ART has consistently increased over a 13-year period. Although improved tolerability and convenience of modern ART regimens probably explain these positive trends, by the end of the study period a substantial proportion of IDUs still had suboptimal adherence, demonstrating the need for additional adherence support strategies.

Frequent methamphetamine injection predicts emergency department utilization among street-involved youth

OBJECTIVES

Methamphetamine (MA) use has been associated with health problems that commonly present in the emergency department (ED). This study sought to determine whether frequent MA injection was a risk factor for ED utilization among street-involved youth.

STUDY DESIGN

Prospective cohort study.

METHODS

Data were derived from a street-involved youth cohort known as the 'At Risk Youth Study'. Behavioural data including MA use were linked to ED records at a major inner-city hospital. Kaplan-Meier and Cox proportional hazards methods were used to determine the risk factors for ED utilization.

RESULTS

Between September 2005 and January 2007, 427 eligible participants were enrolled, among whom the median age was 21 (interquartile range 19-23) years and 154 (36.1%) were female. Within 1 year, 163 (38.2%) visited the ED, resulting in an incidence density of 53.7 per 100 person-years. ED utilization was significantly higher among frequent (i.e. ≥daily) MA injectors (log-rank P = 0.004). In multivariate analysis, frequent MA injection was associated with an increased hazard of ED utilization (adjusted hazard ratio = 1.84, 95% confidence interval 1.04-3.25; P = 0.036).

CONCLUSIONS

Street-involved youth who frequently inject MA appear to be at increased risk of ED utilization. The integration of MA-specific addiction treatment services within emergency care settings for high-risk youth is recommended.

Impact of hepatitis C virus infection on all-cause and liver-related mortality in a large community-based cohort of inner city residents

The aim of this study was to measure the impact of hepatitis C virus (HCV) infection on mortality in a cohort of inner city residents. The Community Health and Safety Evaluation is a community-based study of inner city residents followed retrospectively and prospectively through linkages with provincial virology and mortality databases. We identified participants having received HCV antibody testing, evaluated cause-specific mortality rates and factors associated with all-cause and liver-related mortality using Cox Proportional Hazards models. Overall, 2332 participants received HCV antibody testing (recent non-injection drug use - 81%). The prevalence of HCV and HIV was 64% (1495 of 2332) and 21% (485 of 2332), respectively. Between January 2003 and December 2007, there were 180 deaths (192 per 10.000 person-years; 95% CI: 165, 222), with 21% HIV-related, 20% drug-related and 7% liver-related. Mortality was associated with age >50 [adjusted hazard ratio (AHR) 2.80 vs < 40 years (referent group); 95% CI 1.93, 4.07, P < 0.001] and HIV infection (AHR 3.81; 95% CI 2.72, 5.34, P < 0.001), but not positive HCV antibody status (AHR 1.19; 95% CI 0.83, 1.72, P = 0.35). Liver-related mortality was associated with age >50 [AHR 18.49 vs < 40 years (referent group); 95% CI 2.27, 150.41, P < 0.001] and positive HCV antibody status (AHR 7.69; 95% CI 0.99, 59.98, P = 0.052). This study demonstrates a high rate of mortality in this population, particularly those with HIV. HCV-infected inner city residents >50 years of age were at significant risk of liver-related mortality. Continued surveillance of this population infected with HCV in the 1970s and 1980s is important.

The Audio Recorded Cognitive Screen (ARCS) in patients with multiple sclerosis: a practical tool for multiple sclerosis clinics

Background: Cognitive impairment is a common complication of multiple sclerosis, even in early stage disease, with significant impacts on life quality and social interaction. However, its detection is highly test-dependent.

Objective: To validate a recently described screening tool, the ARCS, for detecting cognitive impairment in a multiple sclerosis population.

Methods: The ARCS administers tests of executive function, memory, visual spatial construction and language via an audio device to unsupervised patients who write their responses for later scoring. Some 127 patients with a wide variety of disease course and severity were assessed by ARCS, of whom 87 also completed the Paced Auditory Serial Addition Test (PASAT) and 45 underwent formal (‘gold standard’) neuropsychological testing.

Results: Compared with PASAT, we found that the ARCS showed better sensitivity (86% versus 68%) at equivalent specificity (71%) for detection of impairment in any cognitive domain, and superiority in the detection of memory and executive impairments. Acceptance and completion rates for the ARCS were as good or better than for the PASAT.

Conclusions: ARCS is sensitive, well-tolerated, easy to administer and facilitates comprehensive cognitive assessment in less than 5 min of clinician time. It has several advantages over the PASAT for detecting cognitive impairment in patients with multiple sclerosis.

Prevalence and structural correlates of gender based violence among a prospective cohort of female sex workers

OBJECTIVE

To examine the prevalence and structural correlates of gender based violence against female sex workers in an environment of criminalised prostitution.

DESIGN

Prospective observational study.

SETTING

Vancouver, Canada during 2006-8.

PARTICIPANTS

Female sex workers 14 years of age or older (inclusive of transgender women) who used illicit drugs (excluding marijuana) and engaged in street level sex work.

MAIN OUTCOME MEASURE

Self reported gender based violence.

RESULTS

Of 267 female sex workers invited to participate, 251 women returned to the study office and consented to participate (response rate of 94%). Analyses were based on 237 female sex workers who completed a baseline visit and at least one follow-up visit. Of these 237 female sex workers, 57% experienced gender based violence over an 18 month follow-up period. In multivariate models adjusted for individual and interpersonal risk practices, the following structural factors were independently correlated with violence against female sex workers: homelessness (adjusted odds ratio for physical violence (aOR(physicalviolence)) 2.14, 95% confidence interval 1.34 to 3.43; adjusted odds ratio for rape (aOR(rape)) 1.73, 1.09 to 3.12); inability to access drug treatment (adjusted odds ratio for client violence (aOR(clientviolence)) 2.13, 1.26 to 3.62; aOR(physicalviolence) 1.96, 1.03 to 3.43); servicing clients in cars or public spaces (aOR(clientviolence) 1.50, 1.08 to 2.57); prior assault by police (aOR(clientviolence) 3.45, 1.98 to 6.02; aOR(rape) 2.61, 1.32 to 5.16); confiscation of drug use paraphernalia by police without arrest (aOR(physicalviolence) 1.50, 1.02 to 2.41); and moving working areas away from main streets owing to policing (aOR(clientviolence) 2.13, 1.26 to 3.62).

CONCLUSIONS

Our results demonstrate an alarming prevalence of gender based violence against female sex workers. The structural factors of criminalisation, homelessness, and poor availability of drug treatment independently correlated with gender based violence against street based female sex workers. Socio-legal policy reforms, improved access to housing and drug treatment, and scale up of violence prevention efforts, including police-sex worker partnerships, will be crucial to stemming violence against female sex workers.

Low uptake of treatment for hepatitis C virus infection in a large community-based study of inner city residents

Despite the availability of effective therapy for hepatitis C virus (HCV) infection, there are little data on the uptake of treatment. We evaluated factors associated with HCV infection and the uptake of HCV treatment in a large community-based inner city cohort in Vancouver, Canada. The Community Health and Safety Evaluation is a cohort study of inner city residents recruited from January 2003 to June 2004. HIV and HCV status and information on prescriptions for HCV treatment were determined through linkage with provincial databases. HCV prevalence was calculated and factors associated with HCV infection were identified. HCV treatment uptake and incidence of HCV infection from January 2000 to December 2004 were expressed in terms of person-years of observation. Among 2913 individuals, HCV antibody testing was performed in 2118 and the HCV seroprevalence was 64.2% (1360 of 2118). In total, 1.1% of HCV antibody-positive individuals (15 of 1360) initiated treatment for HCV infection from January 2000 to December 2004 [0.28 cases per 100 person-years (95% CI, 0.15-0.46)]. Three of 15 (20.0%) treated individuals achieved a sustained virological response. During the same period, the incidence of HCV infection was 7.26 cases (95% CI, 5.72-8.80) per 100 person-years. Overall, the rate of new HCV seroconversions in this cohort in the study period was about 25 times the rate of HCV treatment uptake. There are extremely low rates of HCV treatment initiation and very limited effectiveness, despite a high prevalence of HCV infection in this large community-based cohort of inner city residents with access to universal healthcare.

Condom use among injection drug users accessing a supervised injecting facility

OBJECTIVES

Although supervised injecting facility (SIF) use has been associated with reductions in injection-related risk behaviours, the impact of SIFs on the sexual behaviour of injection drug users (IDUs) has not been thoroughly investigated. Therefore, we examined the patterns and predictors of condom use among SIF users in Vancouver, Canada.

METHODS

We performed a longitudinal analysis of the factors associated with consistent condom use among IDUs recruited from within a SIF.

RESULTS

Among 1090 individuals, 650 (59.6%) reported a sexual partner in the past 6 months at baseline. Consistent condom use was reported by 108 (25.3%) and 205 (61.6%) individuals reporting regular or casual partners, respectively. After 2 years of observation, these proportions increased to 32.9% and 69.8%, respectively. In multivariate analysis, predictors of consistent condom use with regular partners included HIV positivity (adjusted odds ratio (AOR) 2.23; 95% CI 1.51 to 3.31), injecting with a sex partner (AOR 0.50; 95% CI 0.37 to 0.68), enrollment in addiction treatment (AOR 0.68, 95% CI 0.52 to 0.89) and time since recruitment (AOR 1.29; 95% CI 1.06 to 1.55 per year). Predictors of consistent condom use with casual partners included HIV positivity (AOR 1.70; 95% CI 1.03 to 2.81), syringe borrowing (AOR 0.54; 95% CI 0.32 to 0.91) and syringe lending (AOR 0.52; 95% CI 0.32 to 0.84).

CONCLUSIONS

Our results demonstrate that among SIF users, consistent condom use was more frequent among casual sex partners and among HIV positive individuals. Importantly, while the prevalence of consistent condom use was low at baseline, it increased over time. Our findings suggest a possible beneficial effect of the SIF on safer sexual practices.

Drug sharing with clients as a risk marker for increased violence and sexual and drug-related harms among survival sex workers

Previous studies have described links between violence, decreased condom use and drug sharing among intimate partners, though limited information exists about the predictors of drug sharing among female sex workers and their clients. The following analysis explored the association between sharing illicit drugs with clients and sexual and drug-related harms among survival sex workers. A total of 198 women participated in interview-administered questionnaires and confidential HIV testing. Of the total, 117 (59%) reported sharing drugs with clients/johns in the last six months and crack cocaine was the primary drug shared (n=108). In logistic regression analysis, sharing drugs with clients/johns was associated with borrowing a used crack pipe (AOR=5.63; 95%CI: 2.71-9.44; p<0.001), intensive/daily crack cocaine smoking (AOR=3.78; 95%CI:1.60-8.92; p<0.002), inconsistent condom use by a client/john (AOR=3.17; 95%CI:1.48-6.77; p<0.003) and having a recent bad date (verbal harassment, physical and/or sexual assault) (AOR=2.71; 95%CI:1.17-6.32; p=0.021). Sharing illicit drugs with clients/johns may be a crucial risk marker for increased violence and sexual and drug-related harms among survival sex workers. HIV prevention and harm reduction initiatives targeting both women and clients/johns are urgently needed, including enhanced support for community and peer-driven sex work initiatives, to address some of the structural facilitators for HIV transmission.

Public injecting among a cohort of injecting drug users in Vancouver, Canada

BACKGROUND

Despite the implementation of policy interventions to address open drug consumption, public injecting continues to occur in many urban settings. This study sought to examine public injecting among a community-recruited cohort of injecting drug users (IDUs) in Vancouver.

METHODS

The prevalence and correlates of recent public injecting among participants enrolled in the Vancouver Injection Drug User Study during the period of 1 December 2003 to 30 November 2005 were examined prospectively using generalised estimating equations (GEEs).

RESULTS

Among the sample of 620 active IDUs, at some point during the study period, 142 (22.9%) individuals reported "usually" or "always" injecting in public in the 6 months prior to their study visit. Factors that were significant and positively associated with recent frequent public injecting in multivariate GEE analysis include homelessness (adjusted OR (AOR) 6.70); frequent crack use (AOR 1.48); and frequent heroin injection (AOR 1.56). Recent frequent public injecting was found to be negatively associated with cooking and filtering drugs prior to injecting (AOR 0.50) and older age (AOR 0.95).

CONCLUSION

The findings indicate that a substantial proportion of local IDUs frequently inject in public, and those who report recently injecting in public spaces appear to be a vulnerable population facing significant health hazards. The provision of secure housing may have the potential to protect the health of IDUs in this setting and significantly decrease the prevalence of public injecting. In addition, the findings support previous work suggesting that removing barriers to the use of Vancouver's existing supervised injection site may serve to further reduce public drug use.

Determinants of HAART discontinuation among injection drug users

The objective of this study was to identify psychosocial determinants of, and self-reported reasons for, HAART discontinuation among HIV-positive injection drug users (IDUs). We examined correlates between sociodemographic characteristics, drug use and risk behaviors, outcome expectations, adherence self-efficacy, social support and HAART discontinuation among 160 HIV-positive participants in the Vancouver Injection Drug Users' Study (VIDUS). Logistic regression was used to identify the factors independently associated with discontinuation of HAART. Seventy-one (44%) study participants discontinued HAART during the study period. Factors independently associated with discontinuation of HAART included recent incarceration (OR = 4.84, p = 0.022), negative outcome expectations (OR = 1.41, p = 0.001), adherence efficacy expectations (OR = 0.70, p = 0.003) and self-regulatory efficacy (OR = 0.86, p = 0.050). The most frequently cited reasons provided for discontinuing HAART were being in jail (44%) and medication side effects (41%). The results of this study suggest that psychological constructs derived from self-efficacy theory are highly germane to the understanding of HAART discontinuation behavior and interventions that may change it. Incarceration may result in interruptions in HAART among IDUs, and programmatic changes may be needed to promote optimal retention on HAART among incarcerated HIV-infected IDUs.

Differences in access to care among injection drug users infected either with HIV and hepatitis C or hepatitis C alone

Access to HCV (Hepatitis C virus) care for HIV/HCV-co-infected patients is an urgent public health concern. The objective of the present study was to describe the self-reported health status of HIV/HCV-co-infected and HCV-mono-infected injection drug users and to describe their access to HCV-related care. Beginning in May 1996, persons who had injected illicit drugs in the previous month were recruited into the Vancouver Injection Drug User Study (VIDUS). At baseline and then semi-annually, participants complete an interviewer-administered questionnaire. Blood is drawn at each semi-annual interview and tested for HIV and Hepatitis C infection. Data for this descriptive, cross-sectional study were drawn from the most recent of either the July 2003 or December 2003 nurse-administered questionnaire. Statistics used were the chi-square, Wilcoxon Rank Sum and Student's t-test. Logistic regression was used to examine factors independently associated with accessing HCV care. There were 707 individuals eligible for this analysis, including 240 HIV/HCV-co-infected and 467 HCV-mono-infected persons. Co-infected individuals were more likely to be female, younger, of Aboriginal ethnicity and less likely to use heroin daily. The HCV-mono-infected group tended to report higher rates of HCV-related symptoms, including fatigue, liver pain, nausea, night-sweats and stomach pain. However, it was the HIV/HCV-co-infected group who were more likely to report that they believed their hepatitis C was affecting them. The HIV/HCV-co-infected group were also more likely to report having received any hepatitis-related follow-up care, including blood work, liver biopsies and referrals to specialists. In logistic regression analysis, factors independently associated with ever receiving any hepatitis C related follow-up were HIV/HCV-co-infection (AOR 3.1; 95% CI: 2-4.7), being older (AOR 1.04; 95% CI: 1.02-1.06 per year older), using heroin daily (AOR 0.54; 95% CI: 0.36-0.82) and believing that hepatitis C was affecting one's health (AOR 1.4; 95% CI: 1.0-2.1). In conclusion, our data indicate more HCV healthcare utilization among those HIV/HCV-co-infected.

Prevalence and correlates of hepatitis C infection among users of North America's first medically supervised safer injection facility

BACKGROUND

North America's first medically supervised safer injection facility (SIF) for illicit drug users was opened in Vancouver, Canada on 22 September 2003. We examined the prevalence and correlates of hepatitis C (HCV) infection among a representative cohort of SIF users.

METHODS

Users of the Vancouver SIF were selected at random and asked to enrol in the Scientific Evaluation of Supervised Injecting (SEOSI) cohort. At baseline, venous blood samples were collected and an interviewer-administered questionnaire was performed. Participants who were HCV-positive were compared with HCV-negative subjects using bivariate and logistic regression analyses.

RESULTS

Between 1 December 2003 and 30 July 2004, 691 participants were enrolled into the SEOSI cohort, among whom 605 (87.6%) were HCV-positive at baseline. Factors independently associated with HCV infection in logistic regression analyses included: involvement with the sex trade [adjusted odds ratio (AOR) 3.7, 95% confidence interval (CI) 2.1-6.1], history of borrowing syringes (AOR 1.8, 95%CI 1.1-2.9), and history of incarceration (AOR 2.6, 95%CI 1.5-4.4). Daily heroin use was protective against HCV infection (AOR 0.6, 95%CI 0.3-0.9).

CONCLUSION

The SIF has attracted injection drug users with a high burden of HCV infection and a substantial proportion of uninfected individuals. Although cross-sectional, this study provides some insight into historical risks for HCV infection among this population, and prospective follow-up of this cohort will be useful to determine if use of the SIF is associated with reduced risk behaviour and HCV incidence.

High rates of primary care and emergency department use among injection drug users in Vancouver

BACKGROUND

Frequent use of emergency rooms by injection drug users (IDUs) has been attributed to a lack of access to primary care and barriers to health services. Using a community-based sample of IDUs, we examined rates of primary care and emergency room use among IDUs and identified correlates of frequent emergency department use.

METHODS

From January to November 2003, we enrolled IDUs into a prospective cohort study involving a baseline questionnaire, comprehensive retrospective and prospective health record linkages. We examined rates of primary care and emergency department utilization, and diagnoses upon arrival in the emergency room. Logistic regression was used to determine factors independently associated with frequent emergency room use.

RESULTS

Of the 883 IDUs included in this analysis, 687 (78 per cent) accessed a primary care clinic in the previous year, while 528 (60 per cent) participants accessed the emergency room (ER) during the years 2002 and 2003. Abscesses, cellulitis and other skin infections accounted for the greatest proportion of ER use. Factors independently associated with frequent ER use included: frequent crystal methamphetamine injection (AOR = 2.4, 95 per cent CI: 1.0-5.6); non-fatal overdose (AOR = 2.1, 95 per cent CI: 1.4-3.3); HIV-positive status (AOR = 1.5, 95 per cent CI: 1.1-2.1), having been physically assaulted (AOR = 1.5, 95 per cent CI: 1.1-2.1); and primary care utilization (AOR = 1.5, 95 per cent CI: 1.0-2.1).

DISCUSSION

high rates of ER use were observed among IDUs, despite high rates of primary care use among this same population. ER use was due primarily to preventable injection-related complications that are less amenable to primary care interventions, and therefore educational and prevention efforts that encourage and enable sterile injection practices should be promoted.

Behavioral and neurochemical effects of 3-OH-pip-BTCP, an active metabolite of BTCP in rats

The effects of N-[1-(2-benzo[b]thiophenyl)cyclohexyl]piperidin-3-ol (3-OH-pip-BTCP), an active metabolite of N-[1-(2-benzo[b]thiophenyl)cyclohexyl]piperidine (BTCP) was examined on locomotor activity and dopamine (DA) levels in the nucleus accumbens (NAcc) in rats. To study the stimulant action of 3-OH-pip-BTCP, rats were placed into activity chambers and injected with the compound (0-40 mg/kg, i.p.). To measure the effects of 3-OH-pip-BTCP on DA levels, rats were implanted with microdialysis probes into the NAcc and the same doses as used in the locomotor activity experiment were administered i.p. 3-OH-pip-BTCP dose-dependently increased locomotor activity and DA levels in the NAcc which lasted 4-5 h at 20 and 40 mg/kg. The results suggest that 3-OH-pip-BTCP exerts long lasting stimulating effects on locomotion and extracellular DA levels in the NAcc, suggesting that 3-OH-pip-BTCP contributes importantly to the pharmacological effects of its parent compound, BTCP.

Bacteremia due to Leptotrichia trevisanii sp. nov

A thin, filamentous, non-motile, aerotolerant, anaerobic, gram-negative bacterium was isolated from the blood of a 46-year-old man who was diagnosed as having acute myeloid leukemia. The organism had a positive catalase reaction but was negative in indole and oxidase tests. A commercially available system failed to identify the bacterium, but 16S rRNA gene sequencing showed it to be most closely related (97% similarity) to a recently isolated Leptotrichia sp. The DNA base composition was 29.7% mol G+C, and the organism produced lactate as the sole end-product of glucose fermentation. These data indicate the isolate is a new species of Leptotrichia for which the name Leptotrichia trevisanii sp. nov. is proposed.

Emotional change processes in music-assisted reframing

Affective processes are critical to understanding and promoting lasting therapeutic change. Using a sample of 40 anxious adults, the researchers examined the use of music to increase affective modification and emotional restructuring in a cognitive reframing intervention. Subjects were assigned to either a typical reframing intervention or a music-assisted reframing intervention. Using the State-Trait Anxiety Inventory, Subjective Units of Distress Scale, Depression Adjective Checklist, and a Think-Aloud measure, the groups were compared on basis of anxiety-reduction, affective modification, and imagery vividness. Results indicate that the music-assisted reframing intervention was more efficacious than the typical reframing intervention in reducing anxiety, modifying affect, and promoting imagery-vividness.

Enduring resistance to extinction of cocaine-seeking behavior induced by drug-related cues

The conditioning of cocaine's pharmacological actions with environmental stimuli is thought to be a critical factor in long-lasting relapse risk associated with cocaine addiction. To study the significance of environmental stimuli in enduring vulnerability to relapse, the resistance to extinction of drug-seeking behavior elicited by a cocaine-related stimulus was examined. Male Wistar rats were trained to associate discriminative stimuli (S(D)) with the availability of intravenous cocaine (S(+)) vs. the availability of non-rewarding (S(-)) saline solution, and then placed on extinction conditions during which intravenous solutions and S(D) were withheld. The rats were then presented with the S(+) or S(-) alone in 60-min reinstatement sessions conducted at 3-day intervals. To examine the long-term persistence of the motivating effects of the cocaine S(+), a subgroup of rats was re-tested following an additional three months of abstinence during which time the rats remained confined to their home cages. Re-exposure to the cocaine S(+) selectively elicited robust responding at the previously active lever. The efficacy and selectivity of this stimulus to elicit responding remained unaltered throughout a 34-day phase of repeated testing as well as following the additional extended abstinence period. In pharmacological tests, conducted in a separate group of rats, the dopamine (DA) D(1) antagonist SCH 39166 (10 microg/kg), the D(2/3) antagonist nafadotride (1 mg/kg), and the D(2/3) agonist PD 128907 (0.3 mg/kg) suppressed the cue-induced response reinstatement while the D(1) agonist SKF 81297 (1.0 mg/kg) produced a variable behavioral profile attenuating cue-induced responding in some rats while exacerbating this behavior in others. The results suggest that the motivating effects of cocaine-related stimuli are highly resistant to extinction. The undiminished efficacy of the cocaine S(+) to induce drug-seeking behavior both with repeated testing and following long-term abstinence parallels the long-lasting nature of conditioned cue reactivity and cue-induced cocaine craving in humans, and confirms a significant role of learning factors in long-lasting vulnerability to relapse associated with cocaine addiction. Finally, the results support a role of DA neurotransmission in cue-induced cocaine-seeking behavior.

Unsafe injection practices in a cohort of injection drug users in Vancouver: could safer injecting rooms help?

BACKGROUND

In several European countries safer injecting rooms have reduced the public disorder and health-related problems of injection drug use. We explored factors associated with needle-sharing practices that could potentially be alleviated by the availability of safer injecting rooms in Canada.

METHODS

The Vancouver Injection Drug User Study is a prospective cohort study of injection drug users (IDUs) that began in 1996. The analyses reported here were restricted to the 776 participants who reported actively injecting drugs in the 6 months before the most recent follow-up visit, during the period January 1999 to October 2000. Needle sharing was defined as either borrowing or lending a used needle in the 6-month period before the interview.

RESULTS

Overall, 214 (27.6%) of the participants reported sharing needles during the 6 months before follow-up; 106 (13.7%) injected drugs in public, and 581 (74.9%) reported injecting alone at least once. Variables independently associated with needle sharing in a multivariate analysis included difficulty getting sterile needles (adjusted odds ratio [OR] 2.7, 95% confidence interval [CI] 1.8-4.1), requiring help to inject drugs (adjusted OR 2.0, 95% CI 1.4-2.8), needle reuse (adjusted OR 1.8, 95% CI 1.3-2.6), frequent cocaine injection (adjusted OR 1.6, 95% CI 1.1-2.3) and frequent heroin injection (adjusted OR 1.5, 95% CI 1.04-2.1). Conversely, HIV-positive participants were less likely to share needles (adjusted OR 0.5, 95% CI 0.4-0.8), although 20.2% of the HIV-positive IDUs still reported sharing needles.

INTERPRETATION

Despite the availability of a large needle-exchange program and targeted law enforcement efforts in Vancouver, needle sharing remains an alarmingly common practice in our cohort. We identified a number of risk behaviours--difficulty getting sterile needles, needle sharing and reuse, injection of drugs in public and injecting alone (one of the main contributing causes of overdose)--that may be alleviated by the establishment of supervised safer injecting rooms.

5-HT(1A) receptor mutant mice exhibit enhanced tonic, stress-induced and fluoxetine-induced serotonergic neurotransmission

Mutant mice that lack serotonin(1A) receptors exhibit enhanced anxiety-related behaviors, a phenotype that is hypothesized to result from impaired autoinhibitory control of midbrain serotonergic neuronal firing. Here we examined the impact of serotonin(1A) receptor deletion on forebrain serotonin neurotransmission using in vivo microdialysis in the frontal cortex and ventral hippocampus of serotonin(1A) receptor mutant and wild-type mice. Baseline dialysate serotonin levels were significantly elevated in mutant animals as compared with wild-types both in frontal cortex (mutant = 0.44 +/- 0.05 n M; wild-type = 0.28 +/- 0.03 n M) and hippocampus (mutant = 0.46 +/- 0.07 n M; wild-type = 0.27 +/- 0.04 n M). A stressor known to elicit enhanced anxiety-like behaviors in serotonin(1A) receptor mutants increased dialysate 5-HT levels in the frontal cortex of mutant mice by 144% while producing no alteration in cortical 5-HT in wild-type mice. There was no phenotypic difference in the effect of this stressor on serotonin levels in the hippocampus. Fluoxetine produced significantly greater increases in dialysate 5-HT content in serotonin(1A) receptor mutants as compared with wild-types, with two- and three-fold greater responses being observed in the hippocampus and frontal cortex, respectively. This phenotypic effect was mimicked in wild-types by pretreatment with the serotonin(1A) antagonist 4-iodo-N-[2-[4-(methoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridinyl-benzamide (p-MPPI). These results indicate that deletion of central serotonin(1A) receptors results in a tonic disinhibition of central serotonin neurotransmission, with a greater dysregulation of serotonin release in the frontal cortex than ventral hippocampus under conditions of stress or increased interstitial serotonin levels.