The COVID-19 pandemic led to lower rates of testing for HIV and hepatitis C virus (HCV) and reduced HCV treatment uptake. It is not clear what other temporary or lasting effects the pandemic might have had in Canada on factors associated with HIV and HCV transmission. Using data from the Canadian Coinfection Cohort, we modelled outcomes related to transmission risk over a period starting 2 years before the pandemic and ending 2 years after the pandemic. We fitted generalised additive mixed models to these outcomes, rather than assume a specific functional form for the change in an outcome over time. Our modelling suggests a slow decline in the risk of HIV and HCV transmission for those in care during the period from 2018 to 2024, unaffected by the pandemic. We see a consistent picture across multiple outcomes: declines in detectable and transmissible HIV RNA, in poor adherence to antiretroviral therapy, and in injection drug use. However, a decline in sexual activity during the pandemic was mostly transitory. At the same time, a third of participants were permanently lost to care during the pandemic. Those lost to care were more likely to be using injection drugs or Indigenous people and far more likely to still be HCV RNA positive. HIV and HCV elimination efforts will need to be resourced to re-engage those at greatest risk of transmission who were lost to care during the pandemic.

Bacterial genotyping can support outbreak investigations including skin and soft tissue infections point source outbreaks caused by Mycobacterium abscessus. This study presents an innovative approach that combines Nanopore long-read and Illumina short-read whole-genome sequencing (WGS) data using a novel bioinformatic pipeline to identify related M. abscessus isolates.Core-genome SNP phylogeny of Montreal M. abscessus isolatesThe core genome was estimated from open reading frames of the assembled outbreak isolates along with 220 additional isolates from the island of Montreal. M. abscessus subsp. massiliense isolates cultured from the skin infection outbreak patients exhibit high relatedness compared to the Montreal M. abscessus catalog. Physicians and public health authorities identified a potential skin and soft tissue infection outbreak in Montreal, Canada. Six isolates from four patients were retrieved and DNA was sequenced using both Illumina short-read and Oxford Nanopore long-read WGS platforms.Minhash k-mer distances to reference M. abscessus type strains were used to confirm taxonomic identity of clinical isolates. Complete genomes for each isolate were assembled using long-reads and polished using short-read data. Single nucleotide polymorphism (SNP) distances between clinical isolates and the putative earliest outbreak case were used to examine their relatedness. Outbreak isolates were also compared to 220 contemporary Montreal M. abscessus genomes using core-genome (cg) SNPs to assess their relatedness and clustering among locally circulating strains. All outbreak isolates were most closely related to M. abscessus subsp. massilliense. Short reads from the outbreak isolates showed 100% mapping coverage to the complete assembly of the earliest outbreak isolate. All outbreak isolates were found to be nearly identical, differing by only 0-2 SNPs. In comparison, using the more distantly related subspecies reference exaggerated SNP distances between isolates (32-50 SNPs), and between outbreak isolates and the reference (26612-26644 SNPs). The cgSNP phylogenetic tree shows the outbreak isolates are distinct to other Montreal M. abscessus genomes and to the M. abscessus subspecies reference genomes. Our findings indicate that this improved molecular approach leveraging both short and long read sequence data to produce complete genome assemblies of M. abscessus. This helped confirm the relatedness of epidemiologically linked cases and assess their bacterial isolates’ molecular clustering within an extended catalog of locally circulating strains. All Authors: No reported disclosures

BackgroundGay, bisexual, and other men who have sex with men (GBM) report higher use of psychoactive substances, which may contribute to many adverse outcomes.MethodWe examined the incidence of psychosis and associated substance use among GBM compared with males from the general male population. We analyzed data from 798 sexually active GBM from two cohort studies based in Vancouver, Canada, linking their survey data to administrative health records. We matched GBM (1:5) by age and geography to HIV-negative males. We determined incident psychosis using ICD-9/10 codes and examined associated factors using Poisson regression.ResultsIncidence was 1.74 per 100 person-years for GBM and 0.64 for their matches (risk-ratio = 2.71; 95% CI:1.95-3.78). Among GBM, opioid use, living with HIV, unstable housing, and anxiety symptoms were independently associated with psychosis.ConclusionsAddressing social determinants of health for GBM such as unstable housing, particularly among those living with HIV, may reduce the burden of substance-use associated psychosis.

OBJECTIVES:Migrants are disproportionately affected by HIV and face inequities in accessing care. This study examined the HIV care cascade among newly registered adults at the Chronic Viral Illness Service (CVIS). METHODS:We conducted a retrospective cohort study of adults (≥18 years) living with HIV and newly registered at the CVIS, in Montréal, Canada, between January 1st, 2022, and December 31st, 2024. Sociodemographic, clinical and care cascade data were extracted from electronic records. Multivariable logistic regression models, adjusted for age, gender, region of birth and diagnosis type, examined associations between seven migration status categories and cascade outcomes. RESULTS:Among 695 patients, 664 (95%) were born outside Canada and 528 (76%) were refugees/asylum seekers. Of these, 281/695 (40%) had a new HIV diagnosis. Among newly diagnosed refugees/asylum seekers, median time from diagnosis to linkage to care was 28 days (interquartile range [IQR]: 18-42). Median time from linkage to antiretroviral therapy (ART) prescription ranged from 0 (IQR: 0-0) to 18 (IQR: 9-27) days across groups. At 6 months, 618/695 (89%) were retained in care and 603/618 (98%) were on ART. At 12 months, 530/603 (88%) were in care and 511/530 (96%) were virally suppressed. In exploratory adjusted analyses, Canadian citizens had lower odds of retention (aOR 0.32, 95% CI 0.14-0.75) and viral suppression (aOR 0.33, 95% CI 0.15-0.75) at 12 months. CONCLUSIONS:Among newly diagnosed refugees/asylum seekers, linkage to care delays appear to have increased since pre-pandemic estimates. Meaningful heterogeneity across migration groups highlights the limitations of treating migrants as a homogeneous population in HIV care.

ABSTRACT Objectives In Quebec, Canada, vaccination against human papillomavirus (HPV) has been publicly-funded since January 2016 for gay, bisexual, and other men who have sex with men (GBM) aged ≤26 years. The study aimed to analyze data collected in Greater Montreal (Engage study) to evaluate the HPV vaccination program for GBM in Quebec. Study Design Engage is a cohort of sexually active GBM aged ≥16 recruited via respondent-driven-sampling (RDS) in Canada. Participants completed a questionnaire and tested for sexually transmitted infections. Methods RDS-II weights were applied to adjust for recruitment. Subgroups were compared using standardized mean differences. Odds ratios of HPV vaccination and prevalence ratios of anal HPV infection adjusted for potential confounders were estimated using robust regression models. Results Of 1179 participants, 309 were eligible for free HPV vaccination. Vaccine coverage among eligible GBM was 42%. Among those who disclosed same-sex sexual activity and discussed HPV vaccination with their healthcare provider, coverage reached 82%. Anal HPV prevalence among eligible GBM was 26.5% for ≥1 HPV-6/11/16/18 genotypes without significant difference between vaccinated and unvaccinated individuals. Among unvaccinated GBM aged ≤26 who were aware of the vaccine, 60% intended to get vaccinated within the next year. Conclusions One to two years after GBM aged ≤26 were included in the Quebec HPV vaccination program, 42% of eligible GBM in Greater Montreal had been vaccinated. Anal HPV prevalence was high among GBM. Vaccinees were more likely to self-report a prior STI diagnosis. Offering vaccination to all preadolescents in schools appears essential to maximize vaccination benefits.

Objectives Doxycycline as post-exposure prophylaxis (doxy-PEP) has emerged as an efficacious strategy to reduce Chlamydia trachomatis (C. trachomatis), Neisseria gonorrhoeae (N. gonorrhoeae) and syphilis (sexually transmitted infections (STIs)) among gay, bisexual and other men who have sex with men (GBM). There is a need to identify prescribing criteria that maximise the number of STIs averted while minimising excessive use.Design In this prospective longitudinal cohort study with repeated measures and biobehavioural data collection, participants completed a questionnaire and tested for STIs at each visit.Setting Community-based, population-level study conducted in three large Canadian cities between February 2017 and July 2023.Participants 2449 GBM were recruited through respondent-driven sampling (RDS); 1998 had ≥1 follow-up visit, contributing 7551 person-years of observation. Eligible participants were aged ≥16 years, cis- or transgender men, reported sex with another man in the past 6 months and resided in Montreal, Toronto or Vancouver.Primary and secondary outcome measures Adjusted rate ratios (aRR) of STIs, accounting for RDS recruitment, loss to follow-up and confounding were estimated using generalised estimating equations (GEE) Poisson regression. For identified STI risk factors, the proportions of STIs averted through doxy-PEP prescription (based on the efficacy of doxy-PEP for each bacterial STI) and the number needed to treat (NNT) for 1 year to avert one STI, assuming 100% adherence, were calculated.Results Among 1998 participants, the combined incidence rate of any C. trachomatis, N. gonorrhoeae and syphilis infection was 29.5 (95%CI 27.3 to 31.9) per 100 person-years. STI risk factors that had the most impact as doxy-PEP criteria were history of any of the three STIs in the past 12 months (P12M) (aRR=2.0, 95% CI 1.8 to 2.2, 36% STI averted, NNT=2.1); ≥10 male sexual partners in the past 6 months (P6M) (aRR=3.8, 95% CI 3.0 to 4.9, 41% STI averted, NNT=2.4); HIV-pre-exposure prophylaxis (PrEP) use P6M (aRR=1.7, 95% CI 1.5 to 2.0, 29% STI averted, NNT=2.5); use of any chemsex-related substance P6M (aRR=1.2, 95% CI 1.1 to 1.4, 28% STI averted, NNT=2.6); and group sex event attendance P6M (aRR=1.2, 95% CI 1.1 to 1.3, 27% STI averted, NNT=2.3). Reporting≥10 male sex partners P6M represented the most useful criterion for syphilis prevention (52% syphilis infections averted, NNT=20). Prescribing doxy-PEP to GBM having any of the following STI risk factors, namely, ≥1 bacterial STI P12M, ≥10 male sex partners P6M, or HIV-PrEP use P6M, would substantially increase the proportion of all STI diagnoses potentially averted (60%) with minimal increase of the NNT (2.7).Conclusion This work informs on the impact of various doxy-PEP clinical prescribing criteria and demonstrates the benefit of focusing on any of the following three criteria: ≥1 bacterial STI P12M, ≥10 male sex partners P6M or HIV-PrEP use P6M.

Background Many individuals are released from prison with untreated hepatitis C virus (HCV) and face challenges linking to care in the community. This study evaluated the cost-effectiveness of a multidisciplinary model of care compared to standard of care (SOC) across key steps along the HCV care cascade. Methods A prospective, pre-post study was conducted among men incarcerated in Quebec’s largest provincial prison. Intervention participants received care from a nurse, social worker, and patient navigator before release and were offered appointment accompaniment post-release by the patient navigator. SOC participants were encouraged to undergo HCV screening and those with current HCV received a pre-release discharge HCV appointment. The analysis adopted a healthcare system perspective. The primary outcome was sustained virologic response (SVR) within 180 days post-release. Secondary outcomes included linkage to care within 90 days post-release, treatment initiation, and treatment completion. The incremental cost-effectiveness ratio (ICER) was calculated as the difference in costs (Canadian dollars, C$) divided by the difference in outcomes. Results Comparing 20 participants with current HCV infection (HCV RNA+) in both the intervention and the SOC arms, 16 vs. 12 were linked to care, 13 vs. 4 initiated treatment, 8 vs. 2 completed treatment, and 8 vs. 2 achieved SVR, respectively. The corresponding ICERs were C$1,242, C$10,481, C$25,577, and C$25,653 per additional person achieving the outcome. Conclusions Our multidisciplinary model of care increased the proportion of HCV RNA+ people released from prison who subsequently achieved SVR, at an additional cost of C$25,653 per additional patient. This is only C$5,653 more than the estimated cost of direct-acting antivirals, providing an economic rationale for broader implementation.

BACKGROUND:We compared the prevalence of vaccine-preventable anal human papillomavirus (HPV) types among gay, bisexual, and other men who have sex with men (GBM) living in large cities in Canada from 2019 to 2021 by age and HIV status. METHODS:Sexually-active GBM ≥16 years were recruited in Montreal, Toronto, and Vancouver using respondent-driven sampling (RDS). Participants self-reported HPV vaccination and self-collected anal HPV specimens. We estimated the prevalence of vaccine-preventable types for participants during the 2019 to 2021 period. We report RDS-II-weighted prevalence and confounder-adjusted prevalence ratios (aPRs) comparing vaccinated (≥1 dose) and unvaccinated GBM using multivariable Poisson regression. RESULTS:Among 1,159 participants aged 18-83 (median 35 years), 17.6% were living with HIV, and 62.2%, 40.2% and 15.0% were vaccinated in the 16-26, 27-45, and ≥46-year groups, respectively. Among GBM 16-26 years, HPV6/11/16/18 prevalence was lower among those vaccinated ≤23 years (aPR= 0.40, 95% CI: 0.20-0.77), ≥3 years since first dose (aPR=0.39; 95% CI: 0.18-0.85), and those with ≤5 years of sexual activity before vaccination (aPR=0.47; 95%CI: 0.25-0.89). HPV6/11/16/18/31/33/45/52/58 prevalence was lower among those vaccinated ≤26 years in GBM aged 27-45 years (aPR= 0.81, 95% CI, 0.61-1.08), though this did not reach statistical significance. CONCLUSIONS:Five years after implementation of Canadian HPV vaccination programs for younger GBM, anal HPV prevalence was lower among those vaccinated at younger ages and near sexual debut.

Since 2022, a global mpox outbreak in non-endemic countries, including Canada, has spread rapidly, mainly affecting gay, bisexual, and queer men (GBQM). With mpox primarily transmitted through sexual and close physical contact, concerns emerged over the replication of early responses to HIV/AIDS, which was initially labeled as a "gay disease," perpetuating ongoing negative stereotypes and discrimination against GBQM. To prevent potential social and health-related stigmatization, institutional actors, including public health authorities, community-based organizations (CBOs), and clinical bodies, collaborated to provide guidance and promote culturally informed responses. We aimed to examine how health institutional collaborations were formed and maintained as challenges emerged during Canada's mpox outbreak response. We conducted 30 online individual interviews and six small focus groups with 48 CBO practitioners, public health personnel, and clinical providers across Canada. Data were analyzed using institutional ethnography and actor-network theory, through indexing, which involves categorizing and consolidating categories. We mapped four interrelated networks of coordination: assembling the network through existing HIV infrastructures; co-developing public health messaging to increase cultural sensitivity to GBQM's lived experiences; negotiating vaccine eligibility criteria to reflect community realities; and mobilizing networks to deliver vaccines in GBQM community-friendly settings. Regional differences in public health infrastructure influenced the development of coordination, messaging, and access to care. Findings highlight how relational infrastructures developed for HIV were reactivated and repurposed during the mpox response. Investing in and maintaining strong community and public health relationships outside of crisis periods can improve future responses to health emergencies affecting GBQM communities and other marginalized populations.

HIV pre-exposure prophylaxis (PrEP) is proven effective for HIV prevention and recommended for individuals at ongoing and high risk of HIV, including gay, bisexual, and other men who have sex with men (GBMSM) and people who inject drugs (PWID). We used existing national survey data to measure PrEP need in both populations and calculate percentages of use among those meeting indications within each group. We conducted a secondary data analysis of nationally representative data to estimate the percentage of GBMSM and PWID meeting PrEP indications based on 2017 Canadian guidelines. We applied these percentages to recent population size estimates for both groups to estimate the number of people having PrEP indications in each group. Where available, we also used survey data to determine the percentage of people with indications who were not taking PrEP at the time of the survey. An estimated 24.1

OBJECTIVES:Material deprivation (MD), the inability to afford essentials, is linked with poorer HIV clinical outcomes. In Canada, migrants living with HIV are a growing group, yet little is known about their experience of MD, especially early in treatment. This study examined the prevalence, nature, sociodemographic and clinical correlates and longitudinal changes in MD among migrants living with HIV initiating antiretroviral therapy (ART). METHODS:Analyses used data from 56 ART-naïve migrants enrolled in the Antiretroviral Speed Access Program (ASAP), a cohort at the McGill University Health Centre, Montreal, Canada receiving access to rapid, no-cost and onsite bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF). MD was assessed at Weeks 4 and 48 using the 17-item Canadian Material Deprivation Index (CMDI), with deprivation defined as checking ≥2 items. Statistical tests included Fisher's exact, Wilcoxon signed-rank, McNemar's exact and correlation coefficients. RESULTS:At Week 4, 48 (85.7%) participants were materially deprived, most commonly reporting inability to cover an unexpected expense (87.5%), afford dental care (73.2%) or buy small gifts (73.2%). Week 4 MD was significantly associated with occupation (p = 0.020) and migration status (p = 0.016). No statistically significant associations were observed between MD and HIV clinical outcomes. Between Weeks 4 and 48, MD scores declined significantly (median: 7.5 to 4.0; p < 0.001), although 67.9% of participants remained deprived. CONCLUSIONS:Associated with occupation and migrant status, MD was highly prevalent and persistent among migrants living with HIV, despite partial improvement over time, underscoring the need for structural supports. Short-term HIV clinical outcomes appeared unaffected, which may reflect access to rapid, no-cost and onsite ART delivery.

BACKGROUND:Gay, bisexual, and other men who have sex with men (GBM), especially those living with HIV, may face greater substance-related harms. We compared substance use disorder (SUD) diagnoses, SUD-related hospitalizations, and all-cause mortality between GBM and men from the general population in Metro Vancouver. We also explored factors associated with these outcomes among GBM. METHODS:We linked 798 consenting participants from two GBM cohorts (Momentum and Engage) to administrative health data and matched them (1:5) on age, sex, and geography to 3990 HIV-negative British Columbia residents. We calculated incidence rate ratios [IRR] for the three outcomes. We used multivariable regression to examine factors associated with SUD diagnoses and SUD-related hospitalizations among GBM. RESULTS:Compared to men from the general population, GBM had higher rates of SUD diagnoses (IRR=2.73; 95% confidence interval [CI]=2.00-3.73) and SUD-related hospitalizations (IRR=1.97; 95% CI=1.21-3.20), but similar all-cause mortality (IRR=1.03; 95% CI=0.55-1.91). Substance-related deaths were rare (n = 7; all in the matches). Among GBM, SUD diagnoses were associated positively with living with HIV (adjusted IRR [aIRR]=2.95; 95% CI=1.68, 5.17) and recent transactional sex (aIRR=3.71; 95% CI=1.88, 7.33), and negatively with stable housing (aIRR=0.41; 95% CI=0.19, 0.91). SUD-related hospitalizations were associated positively with living with HIV (aIRR=3.10; 95% CI=1.46, 6.56) and recent tobacco use (aIRR=2.42; 95% CI=1.40, 4.17), and negatively with current employment (IRR=0.49; 95% CI=0.26, 0.91) and stable housing (aIRR=0.35; 95% CI=0.20, 0.64). CONCLUSIONS:GBM experienced higher rates of SUD diagnoses and SUD-related hospitalizations. Public health and mental health interventions and policies should respond to GBM's challenges.

Background and Aims:Metabolic dysfunction-associated steatotic liver disease (MASLD) is common in people with HIV (PWH), yet its impact on health-related quality of life (HRQoL) remains poorly characterized. We evaluated the association between MASLD and both generic and liver-specific HRQoL. Methods:We conducted a cross-sectional analysis within a national multicenter cohort of PWH. MASLD was defined as hepatic steatosis (controlled attenuation parameter >248 dB/m) plus at least metabolic comorbidity and significant liver fibrosis as liver stiffness measurement ≥8 kPa on FibroScan. Generic HRQoL was assessed using the Short Form-36 and liver-specific HRQoL using the Chronic Liver Disease Questionnaire (CLDQ). Adjusted estimated mean differences were estimated using multivariable linear regression. Results:Among 519 participants, the prevalence of MASLD and significant liver fibrosis was 41.4% and 7.2%, respectively. MASLD was independently associated with lower generic HRQoL, including reduction of physical functioning (-4.6; 95% confidence interval [CI] -9.12 to -0.01) and general health (-4.5; 95% CI -8.58 to -0.48) on the Short Form-36. Liver-specific HRQoL was more affected; MASLD was associated with a lower overall CLDQ score (-0.29; 95% CI -0.49 to -0.09), driven by worse fatigue, systemic symptoms, emotional symptoms, and worry. Among PWH with MASLD, increasing metabolic comorbidity burden was associated with a dose-response decline in physical HRQoL, whereas liver-specific HRQoL did not differ across comorbidity strata. Significant fibrosis was associated with lower CLDQ activity (-0.62; 95% CI -1.20 to -0.05) and worry (-0.60; 95% CI -1.15 to -0.05). Conclusion:In PWH, MASLD is associated with impaired HRQoL, particularly fatigue, systemic symptoms, and emotional well-being. Greater metabolic burden and liver fibrosis further worsen patient-reported outcomes.

Abstract Background Canada is advancing several reforms to strengthen primary health care. Although lesbian, gay, and bisexual (LGB) individuals experience a higher burden of some health conditions, they remain largely absent from these reforms, partly because of limited data. We assessed differences in primary care utilization between LGB and heterosexual individuals to address this gap. Methods We used data from 91,172 heterosexual and 2,550 LGB participants in the 2015–2016 Canadian Community Health Survey. Guided by Andersen’s Behavioural Model of Health Services Use, we examined the association between primary care physician (PCP) consultation rates and our primary variables of interest: sex and sexuality. Estimates for heterosexual men, heterosexual women, gay and bisexual men (GBM), and lesbian and bisexual women (LBW) were obtained separately. Models were adjusted for additional covariates (predisposing, enabling, and need-based) identified in Andersen’s framework. Poisson regression was used for the main analysis, and results were compared with estimates from double-selection lasso models. Results GBM and LBW had higher PCP consultation rates over a 12-month period compared with heterosexual men. For every 100 PCP consultations among heterosexual men, there were an estimated 129 consultations (95% CI 112 to 148) among GBM and 123 consultations (95% CI 110 to 139) among LBW. In contrast, consultation rates for GBM and LBW were comparable with heterosexual women. Conclusion Even after adjusting for several covariates, GBM and LBW had higher PCP consultation rates than heterosexual men. These findings suggest that PCP engagement among LGB adults differs from that of heterosexual men. The comparability with heterosexual women requires further investigation. More comprehensive data are needed to verify and clarify these findings to support equitable primary care planning.

The progression of metabolic dysfunction-associated steatotic liver disease (MASLD) to severe forms, including metabolic dysfunction-associated steatohepatitis (MASH) and liver fibrosis, involves metabolic dysfunction, genetics, and gut dysbiosis. People with HIV (PWH) represent a high-risk group for MASLD, but the role of gut microbiota alterations in disease severity within this population remains poorly understood. We prospectively recruited PWH with MASLD, defined as the controlled attenuation parameter (CAP) ≥ 238 dB/m, and excluded those with viral hepatitis coinfection or alcohol abuse. Severe MASLD was defined as the presence of MASH (cytokeratin-18 ≥ 130.5 U/L) and/or significant liver fibrosis (liver stiffness ≥ 7.1 kPa). Stool samples were collected for 16S rRNA gene sequencing to characterize gut microbiota composition. Functional predictions were generated using PICRUSt. The differential abundance of bacterial taxa and predicted functions were analyzed using a generalized linear model with a negative binomial distribution. Among 34 PWH with MASLD, 18 (53%) met the criteria for severe MASLD. Microbiota profiling revealed significant differences in bacterial genera between the PWH with and without severe MASLD. Enrichment was observed in the Ruminococcus gnavus group, Negativibacillus, Holdemanella, Subdoligranulum, the Eubacterium hallii group, and Butyricicoccus, while depletion was seen in Prevotella, Alloprevotella, Dialister, Catenibacterium, the Christensenellaceae R 7 group, Clostridium sensu stricto, Olsenella, Oscillospiraceae UCG-005, Libanicoccus, and the Eubacterium siraeum group. Predicted functional pathways related to fatty acid degradation, folate biosynthesis, and amino acids metabolism did not differ between groups. MASLD severity in PWH is associated with a distinct gut microbiota signature, though not with functional pathway alterations. Microbial profiling may complement existing non-invasive biomarkers for risk stratification in this high-risk population.

BACKGROUND:New HIV infections occur annually in Canada, highlighting the need for pre- and postexposure prophylaxis (PrEP and PEP). Through the Canadian Institutes of Health Research (CIHR) Pan-Canadian Network for HIV/AIDS and STBBI (sexually transmitted and blood-borne infections) Clinical Trials Research, we have updated the 2017 guideline on clinical indications and drug regimens for PrEP and PEP in Canada. METHODS:Drawing on meetings with community-based organizations representing key populations affected by HIV in Canada, along with evidence from 3 systematic reviews on PrEP, PEP, and HIV risk assessment tools (searches to June 2024), our diverse panel of 19 experts formulated recommendations on PrEP and PEP. We used a formal evidence-to-decision-making framework and the Grading of Recommendations, Assessment, Development, and Evaluation system. We followed the Guidelines International Network principles for managing competing interests. Our guideline development and reporting adhere with Appraisal of Guidelines for Research and Evaluation II. RECOMMENDATIONS:This guideline contains 31 recommendations and 10 good practice statements. Although it is appropriate to prescribe PrEP to adults and adolescents who request it, clinicians are also encouraged to assess HIV risk during routine health visits to identify people who would benefit from PrEP. Clinicians should elicit information about patients' anatomy and sexual partners in a culturally sensitive and affirming manner to determine which PrEP regimens - daily oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC), on-demand TDF/FTC, daily oral tenofovir alafenamide/emtricitabine, or long-acting injectable cabotegravir - are suitable options. When assessing whether PEP is needed, clinicians should consider the likelihood that the source person has transmissible HIV, as well as the biological risk of HIV transmission based on exposure type. Preferred PEP regimens are dolutegravir plus TDF/FTC, or bictegravir/tenofovir alafenamide/emtricitabine. INTERPRETATION:Multiple safe, effective PrEP and PEP regimens are now available in Canada, making it increasingly possible to find suitable options for all who could benefit. Implementation of this guideline should expand access to biomedical HIV prevention interventions for those at risk and decrease the incidence of HIV in Canada.

Background:Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are major causes of morbidity and mortality worldwide. Measuring the epidemiological burden of HCV and HBV in Canada is essential to measure progress towards global elimination targets and to ultimately eliminate viral hepatitis as a public health concern. Objective:This study aimed to provide the first national estimates of HBV prevalence and unawareness, and to update estimates of HCV incidence, prevalence, and unawareness in the general population and key populations in Canada for 2021. Progress towards elimination targets for 2025, namely incidence, awareness, mortality, and HBV vaccination, was also assessed. Methods:A combination workbook method and mathematical modelling was used to estimate the prevalence and unawareness of chronic hepatitis B (CHB), prevalence and incidence of anti-HCV antibodies, and the prevalence and unawareness of chronic hepatitis C (CHC). Results:The estimated prevalence of CHB was 0.68% (plausible range: 0.40%-0.97%) or 262,000 (152,000-371,000) people in the general population, of whom 42.5% (33.9%-51.0%) were unaware of their infection. Immigrants from countries where HBV is common had the highest prevalence at 4.2% (1.9%-5.6%). An estimated 8,212 new HCV infections occurred in 2021, and the estimated prevalence of CHC was 0.56% (0.15%-0.97%) or 214,000 (58,500-369,000) people, of whom 41.5% (34.3%-48.8%) were unaware of their infection. People who inject drugs had the highest prevalence and largest proportion who were unaware at 36.9% (12.6%-55.1%) and 49.9% (29.0%-70.2%), respectively. Conclusion:While the overall viral hepatitis burden is low in the general Canadian population, these estimates indicate that certain populations and communities remain disproportionately affected. Although Canada has met some of the 2025 targets, more work is needed. To this end, efforts to obtain and standardize provincial and national data will be required to measure progress towards all elimination targets.