Background: HIV-mediated immunosuppression may increase the severity of SARS-CoV-2 infections and impair immune responses to COVID-19 vaccines, particularly for those with low CD4 counts or unsuppressed viral loads. We estimated rates of Omicron-associated COVID-19 outcomes in matched cohorts of people living with HIV and HIV-negative individuals and determined if these rates differed by COVID-19 vaccination status.

Methods: Using administrative databases, we conducted a retrospective, population-based cohort study of people living with HIV aged ≥19 years in Ontario from January 2, 2022 to March 31, 2023. We matched this cohort 1:1 to HIV-negative individuals based on age, sex, residential census tract, and country of origin. We used a Poisson generalized estimating equation clustered by matched pair to derive rate ratios (RR) and 95% confidence intervals (CI) for the first episode of SARS-CoV-2 testing, RT-PCR-confirmed infection, and COVID-19-related hospitalization/death.

Results: Overall 20,978 out of 21,183 (99.0%) people living with HIV were matched. At baseline, the cohorts were identical on matched factors: age (mean=50.5 years), sex (21.9% female), geographic region, and country of origin (72.3% non-immigrant); however, more people living with HIV had received ≥3 doses of COVID-19 vaccines (31.5% vs. 23.9%). People living with HIV had higher incidence rates of testing (182.9 vs. 117.1 per 1000 person-years; RR=1.56, 95%CI=1.46-1.67), infection (51.1 vs. 34.8 per 1000 person-years; RR=1.47, 95%CI=1.34-1.62), and hospitalization/death (8.4 vs. 3.9 per 1000 person-years; RR=2.16, 95%CI=1.70-2.74) compared with matched HIV-negative individuals. These differences persisted independent of COVID-19 vaccination status at baseline (Figure).

Conclusions: During the initial Omicron period, SARS-CoV-2 testing and infection rates were more than 50% higher in people living with HIV than a matched HIV-negative cohort, while COVID-19-related hospitalization/death rates were more than double. Timely booster doses and other pharmaceutical and non-pharmaceutical interventions are needed to reduce the risk of severe outcomes in people living with HIV.

Background: Ongoing monitoring of SARS-CoV-2 seroprevalence is important among people living with HIV who may be at greater risk of severe COVID-19 outcomes. We estimated the seroprevalence of SARS-CoV-2 antibodies among people living with HIV in Ontario.
Methods: We invited participants from the Ontario HIV Treatment Network Cohort Study (OCS) to self-collect a one-time dried blood spot (DBS) sample using at-home collection kits and self-complete a brief questionnaire. DBS samples underwent serologic analyses of SARS-CoV-2 Immunoglobulin G (IgG) antibody levels to three viral antigens: spike protein (S), receptor-binding domain of the spike protein (RBD), and nucleocapsid protein (N). Along with self-reported vaccination status, hybrid immunity was defined as presence of all three antigens, whereas vaccine-induced immunity (VII) was defined as presence of solely anti-S and anti-RBD. We present prevalence estimates with 95% confidence intervals (CI).
Results: 476 people participated between February 2022 and April 2023. Most were men (87%) and white (71%), with a median age of 57 years (Interquartile range (IQR) 47-63)). Nearly all were vaccinated (>98%). All vaccinated participants received at least 2 doses of COVID-19 vaccine; 92% reported 3 or more doses. The prevalence of hybrid immunity was 32% (95%CI 28-36) whereas VII was 66% (95%CI 62-71). Those with hybrid immunity were slightly younger than the VII group (Median: 55 years (IQR 44-61) vs 58 (IQR 49-64); p=0.026). The prevalence of VII was higher among men (67%, 95%CI 62-72) than women (60%, 95%CI 47-72) but did not reach statistical significance.
Conclusions: In a sample of OCS participants, about one third had serologic evidence of a recent SARS-CoV-2 infection. Waning anti-N levels over time may be impacting serologic groupings and will be investigated in upcoming analyses. Continued monitoring of SARS-CoV-2 serology is critical to inform clinical and immunization guidelines for people living with HIV.

Background
Algorithms are often used to identify people who use drugs (PWUD) in administrative data to better understand the health impacts of the drug toxicity crisis. We assessed occurrence of nonfatal and fatal overdoses among individuals identified as PWUD to those not identified as PWUD by a combination of three published and validated algorithms.

Methods
Using COAST study data, we followed people with HIV (PWH) and a 10% random sample of people without HIV (PWoH) in British Columbia from 2012-2020. The study population was stratified based on meeting the criteria of any of three PWUD algorithms in the 5-years before baseline (cohort-entry). We assessed the proportion experiencing ≥1 nonfatal overdose resulting in a healthcare encounter and/or a fatal overdose.

Results
At baseline, 10.1% of 9,430 PWH and 2.1% of 368,732 PWoH were classified as PWUD. The proportions of people experiencing ≥1 nonfatal overdose and a fatal overdose was significantly higher in those identified as PWUD (Table 1). However, 976 of 1206 PWH (80.9%) who experienced ≥1 nonfatal overdose and 173 of 211 PWH (82.0%) who experienced a fatal overdose had not been identified as PWUD. Similarly, 82.5% of PWoH with ≥1 nonfatal overdose and 79.8% of PWoH with a fatal overdose had not been identified as PWUD.

Conclusion
Most people with or without HIV who experienced fatal or nonfatal overdoses, as recorded in this administrative dataset, were not identified as PWUD at baseline. These findings suggest that existing algorithms may significantly under-capture PWUD, even when they are used in concert.

Introduction
Effective surveillance is a core pillar of public health, driving evidence-based action. The national HIV Surveillance System collects HIV diagnosis data submitted by provincial, territorial and other data providers and publishes national trends on HIV epidemiology in Canada. An ongoing Review and Renewal process is aimed at determining what national-level surveillance data is needed by data users, and improving the quality and usefulness of that data in reflecting the current state of the HIV epidemic.

Methods
The review phase of the Review and Renewal involved several steps :
1. Internal technical assessment;
2. Questionnaires among data providers and users;
3. Review of HIV surveillance system practices in other similar countries; and
4. Literature review to identify best practices.
Ongoing engagement with data providers and community members has provided rich information to guide improvements.

Results
Findings from the review phase were synthesized to identify priority areas for the renewal. These included: improving community engagement; improving the quality of and access to data about race and/or ethnicity, gender identity and a person’s identification with populations disproportionately impacted by HIV; reviewing the HIV exposure categories and hierarchy of risk; shifting to HIV stage information instead of separately reporting new AIDS cases; and improving database infrastructure.

Conclusion
The key issues identified during the review phase will inform the subsequent renewal phase. Proposed changes based on these findings will be developed in collaboration with the provincial, territorial, and other data providers, as well as with community members, and their implementation will happen in stages over the coming years. Additionally, as part of the renewal phase, a new data governance framework outlining the guiding principles, roles, responsibilities, and practices regarding HIV surveillance data is being developed to support the improvement of data quality.

Objectives: To understand the impact of demographics, antiretroviral treatment during pregnancy, and other co-factors on the vertical transmission (VT) rates in the Canadian perinatal HIV surveillance cohort of births to women living with HIV (WLWH).

Methods: 23 Canadian pediatric and HIV centres report data yearly, including maternal characteristics, pregnancy antiretroviral treatment (ART) and infant outcomes.

Results: There have been 5893 mother-infant pairs (MIPs) reported since 1990. The number of births to WLWH rebounded from 210 in 2021, the lowest since 2009, to 238 in 2022. In 2022 26% of MIP were living in Ontario, 26% in Quebec, 15% in Saskatchewan,12% in Alberta, 11% in Manitoba, 8% in BC, and 2% in the Atlantic Provinces Among those for whom the risk factor for infection was known, 75% of women acquired HIV heterosexually, 17% through injection drug use and 2% perinatally. In 2022, 56% of mothers were Black and 28% were Indigenous. Since 2015, there have been 1-6 infants per year infected with HIV. With 5 reported cases in 2022, the overall VT rate was. The proportion of pregnant WLWH receiving less than 4 weeks of continuous ART prior to birth was 8.9% in 2022, matching the highest rate since 2011. Among MIPs for whom infant outcomes were known, the VT rate among those who did not receive at least 4 weeks of combined ART prior to delivery (n=17) in 2022 was 23.5%, in contrast to a rate of 0.6% among those who did.

Conclusions: VT rates in MIPs when mothers receive appropriate treatment remains close to zero. The suboptimal treatment rate in 2022 was 8.9%, a rate exceeded only once in the previous 10 years. Continuing effort is required to overcome barriers to timely engagement in prenatal care and HIV treatment in pregnancy.

Introduction: Pre-exposure prophylaxis (PrEP) uptake has contributed to a decrease in HIV transmission in several global jurisdictions. It is important to monitor PrEP uptake and understand trends to identify where and to whom PrEP outreach is required.
Methods: PrEP uptake was estimated using a published algorithm together with branded/generic TDF/FTC and branded TAF/FTC dispensation data extrapolated from 70% coverage of retail pharmacies in Ontario, provided by a private company, IQVIA. Dispensations were assigned to geographic regions based on pharmacy location. To adjust for a major pharmacy that dispenses online, dispensations attributed to that pharmacy’s forward sorting address (IQVIA data) were geographically redistributed proportionate to its clients’ mailing locations. The adjusted estimated number and rates of individuals dispensed PrEP and the “PrEP-to-need ratio” (P2N:proportion of PrEP use relative to first-time HIV diagnoses [as determined by the Ontario HIV Epidemiology Surveillance Initiative]) are described by geographic region.
Results: An estimated 14621 individuals were dispensed PrEP at least once in Ontario in 2022. This is compared to 6378, 9203, 9973 and 12039 dispensed PrEP in 2018, 2019, 2020 and 2021 respectively; an increase of 129.2% from 2018. In 2022, most PrEP users were male (97.0%) and aged 20-40 years (59.0%). Adjustment of the rates of PrEP dispensation and PrEP-to-need ratio using mailed dispensation data resulted in 15 to 40% increases across regions without mailed dispensation and a 70% reduction in regions where mailed dispensation originated from. In 2022, the adjusted rates of PrEP dispensations per 100,000 people and adjusted P2N ratios were highest in Toronto (rate:299.1,P2N:31.2) and Ottawa (rate:159.3,P2N:37.0) followed by South West (rate:41.7,P2N:21.8), Central West (rate:41.9,P2N:13.6), Eastern (rate:32.4,P2N:15.5), and lowest in Central East (rate:22.8,P2N:9.5) and Northern (rate:23.8,P2N:7.5) regions.
Conclusion: PrEP uptake has increased significantly and online PrEP clinics play an important role in distribution. Strategies to optimize geography-based PrEP accessibility are needed.

Transgender populations are disproportionately impacted by HIV and face unique barriers to accessing HIV-related services. Pre-exposure prophylaxis (PrEP) is a highly effective medication that can be taken to reduce the risk of HIV acquisition. While transgender and non-binary individuals may benefit from PrEP, there is no current evidence describing PrEP awareness and uptake among this population in Canada.

This study analyzed data from the 2019 Trans PULSE Canada survey to estimate PrEP awareness and uptake and to identify predictors of PrEP awareness among transgender and non-binary individuals in Canada. Block-wise modified Poisson regression models were used to identify potential predictors of PrEP awareness.

The analytic sample included 1,965 respondents, of whom 71.0% were aware of PrEP, 2.2% had ever used PrEP, and 0.9% were currently using PrEP. The multivariable analysis revealed multiple statistically significant predictors of PrEP awareness, including variables related to sociodemographics, sexual risk, social support, and gender affirmation. Specifically, the results highlighted a need to improve PrEP awareness among respondents who were older, transfeminine, Indigenous, living in Quebec or Atlantic Canada, had high school education or less, and who were not receiving gender-affirming medical care. Respondents who were single or in a nonmonogamous relationship, those who had ever engaged in sex work, and those who had received an HIV/STI test in the past year were more likely to be PrEP-aware. Additionally, reporting higher levels of emotional social support was identified as a facilitator of PrEP awareness, which may be important for informing future health promotion initiatives.

This study highlights the need to improve overall PrEP awareness and uptake among transgender and non-binary communities in Canada. The study identified inequities in PrEP awareness within the population, which may inform future targeted public health initiatives.

BACKGROUND: Although of proven efficacy, HIV PrEP is underused in women. We explored providers’ perspectives on prescribing PrEP to women using the COM-B model for Behaviour change.

METHODS: OBGYN, family, internal, infectious diseases, and preventive medicine physicians/residents, and eligible pharmacists were recruited to complete an online, cross-sectional questionnaire between August/2023-December/2023. Providers self-assessed their Capability, Opportunity, and Motivation to prescribe PrEP to women from 0 (lowest)-100 (highest), following guiding questions designed to operationalize each construct. We analyzed results using descriptive statistics, and compared Motivation according to provider characteristics using non-parametric tests.

RESULTS: Of 241 respondents representing all five Canadian regions, most were women (152/241=63%), residents (89/241=37%) or family physicians (64/241=27%), non-HIV specialists (193/241=80%), managed STIs (219/241=91%) and worked at an academic/community hospital (130/241=54%). Median (IQR) duration of practice was 3 (0,10) years. Median (IQR) self-assessed Capability to prescribe to cis and trans-women, respectively, was 50 (25,80) and 51 (25,84); Opportunity was 40 (13,70) and 37 (10,73); and Motivation was 80 (60,92) and 85 (65, 100); 56 (23%) had ever prescribed to cis-women and 55 (23%) to trans-women Motivation differed by province and scope of practice, among others (Table).

CONCLUSION: Although providers are highly Motivated to prescribe PrEP to cisgender and transgender women, with some variability by geography and professional characteristics, only a quarter have done so, likely due to limited Capability and especially, Opportunity. Interventions to increase PrEP prescribing skills and to help providers identify women in need may help optimize PrEP prescriptions to women in Canada.