Background: Limited disaggregation of HIV/STBBI data by ethnoracial group in Canada constrains understanding of B-STI burden and prevention needs, especially among key populations such as GBM.

Method: We recruited sexually-active GBM aged 16+ years in Vancouver, Toronto, and Montréal using respondent-driven sampling from February 2017 to August 2019. Participants completed computer-assisted self-interviews and nurse-led B-STI testing every 6-12 months through August 2023. We estimated incidence rates (IR) stratified across ethnoracial groups. Using Poisson regression, we estimated associations of incident B-STIs in separate models for each ethnoracial group, controlling for city.

Results: Among 1,981 participants followed for a median of 4.33 years (IQR=3.56-4.64), IR ranged from 32.3-60.8 per 100 person-years. Compared to all other participants, incidence was significantly lower among white GBM (IR-ratio=0.86, 0.75-<1.00) and higher among African GBM (IR-ratio=1.75, 1.03-2.99). Across groups, past six-month (P6M) HIV-PrEP use, higher partner number, amphetamine use, and living with HIV were significantly (p<0.05) associated with higher incidence. Associations also varied across groups, with incidence significantly higher among: cisgender African/Caribbean/Black (ACB) and Indigenous GBM (compared with trans/nonbinary GBM); Latin American and white GBM with P6M cocaine use; ACB GBM with P6M opioid use; and ACB and Asian GBM with annual incomes <$30,000.

Conclusion: Disaggregating B-STI incidence and predictors by ethnoracial group highlights shared drivers of infection (e.g., HIV-PrEP use) and meaningful heterogeneity (e.g., differences in substance use), supporting targeted advocacy and intervention.

Background: Adolescents in Northern Canada experience intersecting social and sexual health inequities that elevate HIV vulnerabilities. Gender and sexual orientation shape access to health and social resources yet are understudied in Northwest Territories (NWT) research. We examined gender and sexual orientation differences and temporal trends in HIV vulnerabilities, social disparities, and resilience among NWT adolescents.

Methods: We conducted repeated cross-sectional surveys with adolescents aged 13–18 years participating in school-based sexual health workshops across the NWT between 2018–2025. Mixed-effects regression models estimated adjusted associations between gender (reference: cisgender boys) and sexual orientation (reference: heterosexual) with HIV vulnerabilities (condom use self-efficacy [CUSE], sexual activity), social disparities (past 3-month substance use, food insecurity), and resilience, adjusting for socio-demographics and time. We assessed effect modification by time.

Results: Participants (n=1,913; mean age: 14.1, standard deviation: 1.2; 70.0% Indigenous) included 45.7% cisgender girls and 19.62% lesbian, gay, bisexual, queer and other sexually diverse (LGBQ+). In adjusted analyses, sexual activity was higher for girls (Adjusted coefficient [Acoef]: 0.06; 95% Confidence Interval [CI]: 0.01-0.12) and LGBQ+ youth (Acoef: 0.10; 95%CI: 0.02-0.18), as was food insecurity (girls: Acoef: 0.15; 95%CI: 0.07-0.23; LGBQ+ youth: Acoef: 0.17; 95%CI: 0.06-0.27). Resilience scores were lower among girls (Acoef: −8.82, 95%CI: -12.25, -5.38) and LGBQ+ youth (Acoef: −13.16; 95%CI: −17.53, −8.80). Substance use was higher among girls (Acoef: 0.11; 95%CI: 0.04-0.18), while CUSE was lower among LGBQ+ youth (Acoef: −1.30; 95%CI: −2.24, −0.35). Over time, food insecurity disparities worsened for girls (Acoef: −0.03; 95%CI: −0.05, −0.02), while resilience improved for girls (Acoef= 0.97; 95%CI: 0.14-1.79) and LGBQ+ youth (Acoef: 1.67; 95%CI: 0.61-2.73).

Results: Gender and sexual orientation-based inequities in HIV vulnerabilities and social determinants persist among NWT adolescents, despite resilience improvements. HIV prevention in NWT schools can integrate gender-transformative, LGBQ+ affirming, and resilience-building approaches while addressing food insecurity and substance use.

Introduction: Previous research has demonstrated high levels of HIV treatment uptake among gay, bisexual and other men who have sex with men (GBM) living with HIV (LWH) in Canada. We measured the proportion with unsuppressed HIV viral load (VL) in follow-up and related correlates among GBM LWH in Vancouver, Toronto and Montreal.
Methods: Sexually-active GBM aged ≥16 years were recruited through respondent-driven sampling from February 2017 to August 2019. Participants completed a computer-assisted self-interview, which included questions about healthcare, substance use, and mental health history, and VL measurements every 6–12 months until March 31, 2024. We measured the proportion of unsuppressed VL (defined as VL ≥200 copies/mL) and used multivariable generalized linear mixed modelling to examine sociodemographic, behavioural, and clinical factors associated with unsuppressed VL at each study visit.
Results: We recruited 215 GBM LWH in Montreal, 100 in Toronto, and 132 in Vancouver. An additional 21 participants acquired HIV in follow-up. Across all cities and study visits, a median of 3.70% had an unsuppressed VL over a median follow-up of 4.21 years (Q1–Q3: 1.45–4.65). In our multivariable model, crack cocaine use in the past six-months (P6M) (AOR=4.48; 95% CI 1.54-13.0) and methamphetamine use in P6M (Adjusted OR=3.52; 95% CI 1.82-6.81) were associated with higher odds of unsuppressed VL. Increasing age (AOR=0.95 per year; 95% CI 0.92-0.99), having a regular healthcare provider (AOR=0.14; 95% CI 0.04-0.48), higher AUDIT-C scores (AOR=0.14; 95% CI 0.04-0.48), and self-reported diagnosis of attention deficit hyperactivity disorder (AOR=0.31; 95% CI 0.10-0.96) had lower odds. There were no differences in odds of unsuppressed VL by city.
Conclusion: Among urban GBM LWH, we found generally low proportions of those with unsuppressed VL, with ensuing low risks of onward transmission. Addressing stimulant use and facilitating healthcare access may further reduce HIV viremia in this population.

Background: Comorbidities among people living with HIV (PLHIV) are a major concern for long-term health outcomes. This study identified prevalent comorbidities and examined their distribution across sociodemographic and priority population groups, focusing on four outcomes: any comorbidity, and three most prevalent comorbidities.
Methods: We analyzed interviewer-administered questionnaire data collected in 2020-2023 from participants in the Ontario HIV Treatment Network Cohort Study (OCS). Chi-square tests assessed associations between participant characteristics and comorbidities. Multivariable logistic regression models estimated adjusted odds ratios (aORs) for the four outcomes across priority populations, controlling for age and duration since HIV diagnosis.
Results: Among 3,282 participants, 77% were male, 23% female, and 61% were aged 50 years or older. The most prevalent comorbidities were mental health conditions (38%), high blood pressure (26%), high cholesterol (25%), diabetes (13%), and bone or joint disorders (10%). Priority populations experienced a higher comorbidity burden, particularly people who inject drugs (PWID), among whom 93.2% reported at least one comorbidity. In adjusted analyses, PWID had higher odds of any comorbidity (aOR=3.10, 95% CI: 1.55–6.38), while Black participants had lower odds compared to non-Black participants (aOR=0.48, 95% CI: 0.37–0.62). Older participants (≥50 years) had increased odds of high blood pressure (aOR=3.36, 95% CI: 2.70–4.19) and high cholesterol (aOR=4.10, 95% CI: 3.23–5.20). Younger participants (<50 years) had higher odds of mental health conditions (aOR=1.87, 95% CI: 1.56–2.24. Mental health conditions were also more common among PWID (aOR=2.88, 95% CI: 2.03–4.08) and Gay, Bisexual, Men who have Sex with Men (GBMSM) (aOR=1.60, 95% CI: 1.37–1.88), while Black participants had lower odds (aOR=0.46, 95% CI: 0.39–0.56).
Conclusion: Comorbidities are highly prevalent among PLHIV, with distinct patterns across physical and mental health outcomes. Targeted, integrated interventions are needed to optimize care for comorbidity burden in specific HIV priority populations.

Background: Manitoba continues to experience high rates of sexually transmitted and blood-borne infections (STBBIs), especially for populations experiencing structural inequities. Our objective is to determine the incidence of STBBI among people experiencing homelessness and impact of a one-door-one-stop strategy.
Methods: Siloam Mission (SM) is a shelter that provides services to 600-800 community members experiencing homelessness and/or vulnerable individuals daily. Within SM, the Saul Sair Health Centre (SSHC), a low-barrier clinic, offers healthcare services from volunteer providers, harm reduction and basic hygiene supplies. We are conducting a prospective cohort study that invites people 18 years or older who visit SM for any reason. Blood, urine, and genital swabs are collected at SSHC on the same appointment, and tested for confirmatory testing for HIV, hepatitis B, C, syphilis, gonorrhea, and chlamydia. We also offer point-of-care testing for syphilis and/or HIV. Follow-up is scheduled at SSHC 8-10 days to deliver STBBI results, treatment on the spot and linkage to care as needed.
Results: 86% of participants agreed to STBBI testing, of those, 52% are females and 48% are males. At least one STBBI was identified in 92% of females and 25% of males, with 30% of females and 8% males having two or more STBBI co-infections. 24% of tested individuals are living with HIV (20% previous diagnosis and 4% new HIV), and 80% of them were not engaged in HIV care.
Among participants who had positive STBBI results, 86% returned for follow-up, which resulted in same day treatment for syphilis, chlamydia and gonorrhea, and referrals to HIV and HCV care. People are also offered access to opioid agonist treatment, where they can receive HIV or HCV treatment.
Conclusions: These results demonstrate the feasibility of STBBI testing and treatment and the high success for return for follow when services are provided at the shelter.

Objectives: The drug toxicity crisis was declared a public health emergency in British Columbia in 2016. However, the impact of the increased contamination of the unregulated drug supply on progression through the HIV care cascade of people living with HIV (PLWH) who use unregulated drugs remains underexplored. A thorough understanding of how barriers and facilitators to cascade progression have evolved in the context of the drug toxicity crisis is critical to ensure optimal HIV clinical outcomes for people who use unregulated drugs (PWUD).

Methods: We analyzed data from a prospective cohort study of PLWH in Vancouver who use unregulated drugs. Data were collected between 2005 and 2020 and comprised semi-annual interviews with participants, HIV clinical monitoring, and a confidential link to antiretroviral therapy (ART) dispensation data. Barriers and facilitators to both cumulative and stepwise care cascade progression were identified using cumulative link mixed-effects models and included demographic, structural, and substance use exposures.

Results: Among 969 participants, 236 (24.4%) reported daily opioid use at baseline. Over the study duration, both daily opioid use (adjusted partial proportional odds ratio [APPO]=0.63, 95% confidence interval [CI]: 0.53–0.75, p<0.001) and a study period (after declaration of the overdose crisis) (APPO=0.59, 95% CI: 0.51–0.69, p<0.001) were independently associated with decreased cumulative cascade progression. Additional barriers to cascade progression included daily unregulated stimulant use (APPO=0.80, 95% CI: 0.71–0.90, p<0.001), recent incarceration (APPO=0.82, 95% CI: 0.68–0.99, p=0.037), and homelessness (APPO=0.58, 95% CI: 0.51–0.66, p<0.001). Engagement in opioid agonist therapy was significantly associated with improved cascade progression (APPO=2.05, 95% CI: 1.79–2.34, p<0.001).

Conclusions: These findings highlight the need to address the changing barriers faced by PLWH who use unregulated drugs in accessing and adhering to HIV care in the context of the drug toxicity crisis.

Background
People practising chemsex report unmet psychosocial and STBBI prevention needs. Our objectives were to 1) characterize gay, bisexual and other men who have sex with men (GBM) engaging in chemsex in Montreal, focusing on sociodemographic factors, use of STBBI prevention strategies, and engagement in health and community services, and 2) identify health, community, and social settings associated with chemsex to inform the development of interventions that would meet these unmet needs.

Methods
We analyzed the most recent visit of Engage Montreal (01/2022- 02/2023), a cohort of sexually active GBM, aged 16+, recruited via respondent-driven-sampling (RDS). We defined chemsex, the main outcome, as self-reported use of crystal methamphetamine (CM), gamma-hydroxybutyrate (GHB), or ketamine in the two hours before or during sex in the past 6 months. We used separate multivariable logistic regressions to identify independent associations between chemsex substance and health, community, and social settings. Models were weighted for recruitment (RDS-II) and loss-to-follow-up, and adjusted for age, education, and income.

Results
Compared with HIV-negative GBM not using PrEP, GBM living with HIV had 7.6 (95%CI:3.9–14.9), 6.5 (3.4–12.7), and 4.6 (2.2–9.6) times higher odds of using CM, GHB, and ketamine during sexual activity, respectively, while GBM on PrEP had 1.9 (1.0-4.0), 4.2 (2.3-7.5), and 2.9 (1.3-6.1) times higher odds, respectively. Using harm reduction services and using drug-related services were strongly associated with CM, GHB, and ketamine use. The odds of attending a bathhouse were 1.9 (1.1-3.5) and 2.1 (1.2-3.5) times higher among CM and GHB users, but was not associated with ketamine use. Ketamine was associated with using an app to connect with other men.

Conclusion
PrEP or HIV care appointments may be opportunities to address unmet psychosocial needs, while harm reduction services and bathhouses may be settings to meet unmet STBBI prevention needs among GBM engaging in chemsex in Montreal.

Background
People who inject drugs (PWID) are a key population for hepatitis C and HIV elimination. Sexualised drug use (SDU), defined as the intentional use of drugs to enhance sexual experiences, may increase the risk of hepatitis C and HIV. However, PWID are diverse and there remains a limited understanding of SDU among PWID. We aimed to examine the substances used among PWID based on sexual partners and SDU.

Methods
Data were drawn from the baseline interview of HEPCO since questions related to SDU were added in November 2022. PWID were defined as having no sex, sex without SDU and sex with SDU. We examined injecting and non-injecting amphetamine, cocaine and heroin use and used robust poisson regression to estimate prevalence ratios adjusted for gender, age and sexualality.

Results
Of 563 PWID, 537 (95%) had a response regarding sex in the previous month; 366 (68%) reported no sex; 85 (16%) reported sex but not SDU and 86 (16%) reported sex and SDU. Compared to the no sex group, there was no statistically significant difference for injection or non-injection heroin use or the injection of amphetamine or cocaine. Compared to those reporting no sex, non-injection cocaine use was 31% higher among those reporting SDU (aPR 1.31, 95%CI 1.16,1.48) and non-injection amphetamine use was 53% higher (aPR 1.53, 95%CI 1.22,1.91).

Conclusion
A minority of participants reported SDU, however the use of non-injecting stimulant drugs is higher among those reporting SDU, suggesting this is an important sub-group of PWID. Further research to understand the context of SDU among PWID should be conducted to inform tailored harm reduction services.