Dual Sexual and Drug-related Predictors of Hepatitis C Incidence among Sex Workers in a Canadian Setting: Gaps and Opportunities for Scale-up of Hepatitis C Virus Prevention, Treatment, and Care

Background  Hepatitis C virus (HCV) represents a significant cause of morbidity and mortality globally. While sex workers may face elevated HCV risks through both drug and sexual pathways, incidence data among sex workers are severely lacking. HCV incidence and predictors of HCV seroconversion among women sex workers in Vancouver, BC were characterized in this study. Methods  Questionnaire and serological data were drawn from a community-based cohort of women sex workers (2010–2014). Kaplan–Meier methods and Cox regression were used to model HCV incidence and predictors of time to HCV seroconversion. Results  Among 759 sex workers, HCV prevalence was 42.7%. Among 292 baseline-seronegative sex workers, HCV incidence density was 3.84/100 person-years (PY), with higher rates among women using injection drugs (23.30/100 PY) and non-injection crack (6.27/100 PY), and those living with HIV (13.27/100 PY) or acute sexually transmitted infections (STIs) (5.10/100 PY). In Cox analyses adjusted for injection drug use, age (hazard ratio (HR) 0.94, 95% confidence interval (CI) 0.86–1.01), acute STI (HR 2.49, 95% CI 1.02–6.06), and non-injection crack use (HR 2.71, 95% CI 1.18–6.25) predicted time to HCV seroconversion. Discussion  While HCV incidence was highest among women who inject drugs, STIs and the use of non-injection stimulants appear to be pathways to HCV infection, suggesting potential dual sexual/drug transmission. Integrated HCV services within sexual health and HIV/STI programs are recommended

A public health response against Strongyloides stercoralis : time to look at soil-transmitted helminthiasis in full

Strongyloides stercoralis infections have a worldwide distribution with a global burden in terms of prevalence and morbidity that is largely ignored. A public health response against soil-transmitted helminth (STH) infections should broaden the strategy to include S. stercoralis and overcome the epidemiological, diagnostic, and therapeutic challenges that this parasite poses in comparison to Ascaris lumbricoides, Trichuris trichiura, and hookworms. The relatively poor sensitivity of single stool evaluations, which is further lowered when quantitative techniques aimed at detecting eggs are used, also complicates morbidity evaluations and adequate drug efficacy measurements, since S. stercoralis is eliminated in stools in a larval stage. Specific stool techniques for the detection of larvae of S. stercoralis, like Baermann's and Koga's agar plate, despite superiority over direct techniques are still suboptimal. New serologies using recombinant antigens and molecular-based techniques offer new hopes in those areas. The use of ivermectin rather than benzimidazoles for its treatment and the need to have curative regimens rather than lowering the parasite burden are also unique for S. stercoralis in comparison to the other STH due to its life cycle, which allows reproduction and amplification of the worm burden within the human host. The potential impact on STH of the benzimidazoles/ivermectin combinations, already used for control/elimination of lymphatic filariasis, should be further evaluated in public health settings. While waiting for more effective single-dose drug regimens and new sensitive diagnostics, the evidence and the tools already available warrant the planning of a common platform for STH and S. stercoralis control

Implications of Cannabis Legalization on Substance-Related Benefits and Harms for People Who Use Opioids : A Canadian Perspective

In 2018, Canada enacted the Cannabis Act, becoming only the second country (after Uruguay) to legalize the recreational consumption of cannabis. Although there is ongoing global disagreement on the risk-benefit profile of cannabis with increasing legalization in many parts of the world, the evidence of rising cannabis use prevalence post-legalization has been consistent. In contrast, post-legalization changes in various cannabis-related metrics have been inconsistent in Canada and other parts of the world. Furthermore, the implications of cannabis legalization on substance-related harms and benefits for people who use unregulated drugs (PWUD), particularly opioids, remain unclear. Finally, while Canada did not legalize cannabis to address the opioid crisis, there is rising scientific and popular interest in the therapeutic potential of cannabis to mitigate opioid-related harms. This perspective highlights the implications of cannabis legalization on substance-related benefits and harms for people who use opioids, the current state of Canadian research, and suggestions for future directions.Medicine, Faculty ofNon UBCMedicine, Department ofReviewedFacult

Characterizing the presence of fentanyl analogues in the unregulated drug supply in British Columbia, Canada

Background: The emergence of fentanyl and its analogues (e.g., carfentanil) have contributed to a rise in overdose-related mortality. The objective of this study was to describe samples containing fentanyl analogues appearing in the unregulated drug supply of British Columbia (BC), Canada. Methods: Point-of-care drug checking data, using a combination of fentanyl immunoassay strips and Fourier-transform infrared spectroscopy (FTIR), were collected at harm reduction sites in BC between 2017 and 2021. A subset of samples were sent for confirmatory analysis using quantitative nuclear resonance spectroscopy, gas chromatography-mass spectrometry, and/or liquid chromatography-mass spectrometry. Results: A total of 22916 samples were tested using point of care technologies, with 43% testing positive for fentanyl via fentanyl test strips. 1467 were sent for confirmatory analysis, and of these 854 (58%) tested positive for fentanyl via fentanyl test strips and 84 (6%) contained at least one fentanyl analogue, including: carfentanil (n=61), acetyl fentanyl (n=15), furanyl fentanyl (n=8) and cyclopropyl fentanyl (n=5). Fourteen (16%) samples containing a fentanyl analogue tested negative via fentanyl immunoassay strips and fentanyl was also not detected using FTIR. Fentanyl analogues in all fourteen samples were identified in trace amounts via confirmatory analysis. Conclusion: Fentanyl analogues were present in the unregulated drug supply and while the risk profiles are known for some, not all are well characterized. These findings underscore the importance of drug checking initiatives for monitoring the unregulated drug market.Medicine, Faculty ofNon UBCMedicine, Department ofPathology and Laboratory Medicine, Department ofPopulation and Public Health (SPPH), School ofUnreviewedFacultyResearche

Methadone maintenance therapy and viral suppression among HIV-infected opioid users: the impacts of crack and injection cocaine use

Background—Methadone maintenance therapy (MMT) is associated with improved HIV treatment outcomes among people who use drugs (PWUD). The extent to which these benefits are sustained in the context of ongoing cocaine use is unclear. We assessed differential impacts of MMT on HIV viral load (VL) suppression in relation to discrete patterns of cocaine use. Methods—Data was drawn from ACCESS, a prospective cohort of HIV-positive PWUD in Vancouver, Canada. Generalized linear mixed-effects were used to model the independent effect of MMT on VL suppression across strata of frequency of cocaine injection and crack smoking (≥daily versus <daily), after adjustment for confounders. Results—The analysis included 397 HIV-positive opioid users who completed ≥1 study interview between 2005 and 2014. At baseline, 304 (77%) reported participation in MMT, 37 (9%) ≥ daily cocaine injection, and 158 (40%) ≥ daily crack smoking. In adjusted analyses, MMT remained independently associated with increased odds of VL suppression in both strata of crack smokers (AOR=3.11, 95% CI: 1.86–5.21 and AOR=1.48, 95%CI: 1.04–2.09, for ≥daily and <daily smokers, respectively), and among <daily cocaine injectors (AOR=1.88, 95%CI 1.38–2.56), but not among ≥daily cocaine injectors (AOR=1.37, 95%CI 0.53–3.49). Longer retention on MMT was positively associated with VL suppression in all strata of cocaine injection and crack smoke.Conclusions—Exposure to MMT was associated with increased odds of VL suppression among HIV- positive opioid users regardless of crack use. However, this beneficial effect of MMT was lost among frequent cocaine injectors with shorter retention on MMT.Medicine, Faculty ofNon UBCMedicine, Department ofPopulation and Public Health (SPPH), School ofReviewedFacultyResearche

Eligibility for heroin-assisted treatment (HAT) among people who inject opioids and are living with HIV in a Canadian setting

Objectives: A growing body of evidence supports the effectiveness of injectable diacetylmorphine (i.e., heroin) for individuals with treatment-refractory opioid use disorder. Despite this evidence, and the increasing toll of opioid-associated morbidity and mortality, it remains controversial in some settings. To investigate the possible contribution of heroin-assisted treatment (HAT) to HIV treatment-related outcomes, we sought to estimate the proportion and characteristics of HIV-positive people who inject opioids that might be eligible for HAT in Vancouver, Canada. Methods: We used data from a prospective cohort of people living with HIV who use illicit drugs in Vancouver, Canada. Using generalized estimating equations (GEE), we assessed the longitudinal relationships between eligibility for HAT, using criteria from previous clinical trials and guidelines, with behavioural, social, and clinical characteristics. Results: Between 2005 and 2014, 478 participants were included in these analyses, contributing 1927 person-years of observation. Of those, 94 (19.7%) met eligibility for HAT at least once during the study period. In a multivariable GEE model, after adjusting for clinical characteristics, being eligible for HAT was positively associated with homelessness, female gender, high-intensity illicit drug use, drug dealing and higher CD4 count. Conclusions: In our study of HIV-positive people with a history of injection drug use, approximately 20% of participants were eligible for HAT at ≥ 1 follow-up period. Eligibility was linked to risk factors for sub-optimal HIV/AIDS treatment outcomes, such as homelessness and involvement in the local illicit drug trade, suggesting that scaling-up access to HAT might contribute to achieving optimal HIV treatment in this setting.Medicine, Faculty ofOther UBCNon UBCMedicine, Department ofReviewedFacult

Prevalence and correlates of intentional substance use to reduce illicit opioid use in a Canadian setting

Background. While preliminary evidence has begun to document intentional use of one substance to reduce the use of another, the phenomenon of drug substitution among people who use illicit opioids remains understudied. Therefore, we sought to estimate the prevalence and correlates of intentional substance use to reduce illicit opioid use among persons who use drugs (PWUD). Methods. We analysed data from three prospective cohorts of PWUD in Vancouver, Canada, using multivariable generalized estimating equations (GEE). Results. Between June 2012 and June 2016, 1527 participants were recruited and contributed 4991 interviews. Of those, 336 (22%) illicit opioid-using participants self-reported substitution to reduce illicit opioid use at least once during study period contributing 467 (9.4%) interviews. Among those interviews, substances substituted for opioids were alcohol (15 participants, 3.2%), stimulants (235, 50.3%), cannabis (129, 27.6%), benzodiazepines (21, 4.5%), and others (20, 4.3%). In multivariable GEE model adjusted for socio-demographic factors, reporting substitution to reduce illicit opioid use was positively associated with greater likelihood of daily cannabis use (Adjusted Odds Ratio = 1.56, 95% Confidence Interval: 1.24–1.96]. Conclusions. While daily cannabis use was associated with reporting opioid substitution attempts, additional study is needed to examine potential of cannabis/cannabinoids to reduce illicit opioid use.Medicine, Faculty ofNon UBCMedicine, Department ofReviewedFacultyResearche