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ObjectivesPopulations who seek HIV pre-exposure prophylaxis (PrEP) are disproportionately affected by hepatitis A virus (HAV), hepatitis B virus (HBV) and human papillomavirus (HPV). We examined immunity/vaccination against these infections among participants in the Ontario PrEP cohort study (ON-PrEP).MethodsON-PrEP is a prospective cohort of HIV-negative PrEP users from 10 Ontario clinics. We descriptively analysed baseline immunity/vaccination against HAV (IgG reactive), HBV (hepatitis B surface antibody >10) and HPV (self-reported three-dose vaccination). We further performed multivariable logistic regression to identify characteristics associated with baseline immunity/vaccination. We used cumulative incidence functions to describe vaccine uptake among participants non-immune at baseline.ResultsOf 633 eligible participants, 59.1% were white, 85.8% were male and 79.6% were gay. We found baseline evidence of immunity/vaccination against HAV, HBV and HPV in 69.2%, 81.2% and 16.8% of PrEP-experienced participants and 58.9%, 70.3% and 10.4% of PrEP-nai¨ve participants, respectively. Characteristics associated with baseline HAV immunity were greater PrEP duration (adjusted OR (aOR) 1.41/year, 95% CI 1.09 to 1.84), frequent sexually transmitted and bloodborne infection (STBBI) testing (aOR 2.38, 95% CI 1.15 to 4.92) and HBV immunity (aOR 3.53, 95% CI 2.09 to 5.98). Characteristics associated with baseline HBV immunity were living in Toronto (aOR 3.54, 95% CI 1.87 to 6.70) or Ottawa (aOR 2.76, 95% CI 1.41 to 5.40), self-identifying as racialised (aOR 2.23, 95% CI 1.19 to 4.18), greater PrEP duration (aOR 1.39/year, 95% CI 1.02 to 1.90) and HAV immunity (aOR 3.75, 95% CI 2.19 to 6.41). Characteristics associated with baseline HPV vaccination were being aged ≤26 years (aOR 9.28, 95% CI 2.11 to 40.77), annual income between CAD$60 000 and CAD$119 000 (aOR 3.42, 95% CI 1.40 to 8.34), frequent STBBI testing (aOR 7.00, 95% CI 1.38 to 35.46) and HAV immunity (aOR 6.96, 95% CI 2.00 to 24.25). Among those non-immune at baseline, overall cumulative probability of immunity/vaccination was 0.70, 0.60 and 0.53 among PrEP-experienced participants and 0.93, 0.80 and 0.70 among PrEP-nai¨ve participants for HAV, HBV and HPV, respectively.ConclusionsBaseline immunity to HAV/HBV was common, and a sizeable proportion of non-immune participants were vaccinated during follow-up. However, HPV vaccination was uncommon. Continued efforts should be made to remove barriers to HPV vaccination such as cost, inclusion in clinical guidelines and provider recommendation.

ObjectivesInfectious syphilis has been proposed as an indication for HIV pre-exposure prophylaxis (PrEP) in women. We explored how many women experienced HIV seroconversion after being diagnosed with syphilis in Ontario between 20 April 2010 and 31 December 2021.MethodsThrough deterministic linkage of laboratory data at the Public Health Ontario laboratory, which conducts the vast majority of syphilis and HIV testing in Ontario, we quantified the number of females with positive syphilis diagnoses who subsequently exhibited HIV seroconversion between April 2010 and December 2021. New HIV cases were identified by diagnostic serology or HIV viral load test result of ≥20 copies/mL at least 60 days after the positive syphilis test. We report aggregate numbers of women with new laboratory evidence of HIV infection after their first positive syphilis test.ResultsAmong 7957 women with positive syphilis tests during the study period, 6554 (82.4%) had linkable HIV serology tests and 133 (1.7%) ever tested HIV positive. With further linkage to viral load data, the number of women who ever had laboratory evidence of HIV infection increased to 184 (2.3%). However, when restricting to women whose first positive HIV test or HIV viral load occurred after their first positive syphilis test, this number decreased to 34 (0.4%). The median (IQR) time between the positive syphilis test and the first laboratory evidence of HIV was 551 (IQR=226–1159) days.ConclusionAlthough it is clinically appropriate to recommend HIV PrEP to women with syphilis, Ontario surveillance data suggest that the population-level impact of this strategy on the HIV epidemic in Ontario would have been modest during this 11-year period. Future studies should explore additional ways of prioritising women for PrEP.

Objectives: The last Canadian biobehavioural surveillance study of HIV and other sexually transmitted and blood-borne infections (STBBI) among gay, bisexual and other men who have sex with men (GBM) was conducted in 2010. We designed a study to measure STBBI prevalence among GBM in metropolitan Montreal, Toronto and Vancouver and to document related preventive and risk behaviours. Methods: The Engage Cohort Study used respondent-driven sampling (RDS) to recruit GBM who reported sex with another man in the past 6 months. At baseline, we examined recruitment characteristics of the samples, and the RDS-II-adjusted distributions of socio-demographics, laboratory-confirmed HIV and other STBBI prevalence, and related behaviours, with a focus on univariate differences among cities. Results: A total of 2449 GBM were recruited from February 2017 to August 2019. HIV prevalence was lower in Montreal (14.2%) than in Toronto (22.2%) or Vancouver (20.4%). History of syphilis infection was similar across cities (14–16%). Vancouver had more HIV-negative/unknown participants who reported never being HIV tested (18.6%) than Toronto (12.9%) or Montreal (11.5%). Both Montreal (74.9%) and Vancouver (78.8%) had higher proportions of men who tested for another STBBI in the past 6 months than Toronto (67.4%). Vancouver had a higher proportion of men who used pre-exposure prophylaxis (PrEP) in the past 6 months (18.9%) than Toronto (11.1%) or Montreal (9.6%). Conclusion: The three largest cities of Canada differed in HIV prevalence, STBBI testing and PrEP use among GBM. Our findings also suggest the need for scale-up of both PrEP and STI testing among GBM in Canada.

Previous work established non-inferiority of switching participants who were virologically suppressed from daily oral standard of care to monthly long-acting intramuscular injections of cabotegravir plus rilpivirine over 96 weeks following a cabotegravir plus rilpivirine oral lead-in. Here, we report an evaluation of switching participants from standard of care oral regimens to long-acting cabotegravir plus rilpivirine via direct-to-injection or oral lead-in pathways.

Background and purpose HIV prevention efforts in Ontario require increased implementation of strategies including post- and pre-exposure prophylaxis. Access to these interventions could be improved by their provision through nurse-led models of care. We assessed nurses’ readiness to deliver these interventions using a behavioral change framework.Methods We distributed an online survey to nurses in every Ontario sexual health clinic, HIV clinic, and community health center between March-June 2018, to determine the level of support for nurse-led postexposure prophylaxis/pre-exposure prophylaxis; we also explored nurses’ “capabilities,” “opportunities,” and “motivations” for providing postexposure prophylaxis/pre-exposure prophylaxis.Results Overall, 72.7% of respondents supported implementation of both nurse-led postexposure prophylaxis and pre-exposure prophylaxis. More experienced nurses were less likely to support nurse-led postexposure prophylaxis and pre-exposure prophylaxis (adjusted odds ratio = 0.55 per decade nursing, 95% confidence interval (0.37, 0.82)). Nurses reported a high degree of knowledge of topics related to postexposure prophylaxis/pre-exposure prophylaxis, with the exception of creatinine interpretation.Conclusions Ontario nurses report high levels of support for nurse-led postexposure prophylaxis and pre-exposure prophylaxis and are well positioned to provide these interventions. Targeted education and implementation efforts are needed to engage these nurses in postexposure prophylaxis and pre-exposure prophylaxis delivery.

To date, only monoclonal antibodies have been shown to be effective for outpatients with COVID-19. Interferon lambda-1 is a type III interferon involved in innate antiviral responses with activity against respiratory pathogens. We aimed to investigate the safety and efficacy of peginterferon lambda in the treatment of outpatients with mild-to-moderate COVID-19.

There is a need for more convenient, less frequent treatment to help address challenges associated with daily oral HIV treatment in people living with HIV, including stigma, pill burden, drug–food interactions, and adherence. The phase 3 ATLAS and FLAIR studies showed non-inferiority of long-acting cabotegravir and rilpivirine dosed every 4 weeks compared with standard oral therapy for the maintenance of virological suppression in adults with HIV-1 over 48 weeks. We present the 96-week findings.

Objectives: HIV pre-exposure prophylaxis (PrEP) is a proven tool for HIV prevention, but PrEP use in Ontario, Canada, and the effects of recent policies are unknown. We estimated the number and characteristics of PrEP users in Ontario and evaluated the impacts of policy changes between July 2015 and June 2018. Methods: We obtained tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) dispensation data for Ontario from IQVIA, and applied an algorithm to identify use for PrEP. We report prevalent PrEP use for the second quarter of 2018 according to age, sex, region, prescriber specialty, and payer type, and generate “PrEP-to-need ratios” (PNR) by dividing these numbers by the estimated numbers of new HIV diagnoses. We used interventional autoregressive integrated moving average models to examine the impact of three policy changes on PrEP use: Health Canada approval (February 2016), availability of generic TDF/FTC and partial public drug coverage (September 2017), and public drug coverage for individuals aged <?25 years (January 2018). Results: The estimated number of individuals receiving PrEP increased 713%, from 374 in 2015 Q3 to 3041 in 2018 Q2. Among PrEP users in 2018 Q2, 97.5% were male, 60.4% were <?40 years, 67.7% obtained PrEP from a family physician, 77.2% used private insurance, and 67.0% were in Toronto. PNRs were highest in 30–39-year-olds, males, Toronto and the Central East and West regions. Time series analyses found that Health Canada approval (p?=?0.0001) and introducing generics/partial public drug coverage (p?=?0.002) led to significantly increased use. Conclusions: PrEP use has risen in Ontario in association with favourable policy changes, but remains far below guideline recommendations.

ObjectiveTo estimate the real world effectiveness of modified vaccinia Ankara-Bavarian Nordic (MVA-BN) vaccine against mpox infection.DesignEmulation of a target trial.SettingLinked databases in Ontario, Canada.Participants9803 men aged ≥18 years with a history of being tested for syphilis and a laboratory confirmed bacterial sexually transmitted infection (STI) in the previous year, or who filled a prescription for HIV pre-exposure prophylaxis in the previous year. On each day between 12 June 2022 and 27 October 2022, those who had been vaccinated 15 days previously were matched 1:1 with unvaccinated men by age, geographical region, past HIV diagnosis, number of bacterial STI diagnoses in the previous three years, and receipt of any non-MVA-BN vaccine in the previous year.Main outcome measureThe main outcome measure was vaccine effectiveness ((1–hazard ratio)×100) of one dose of subcutaneously administered MVA-BN against laboratory confirmed mpox infection. A Cox proportional hazards model was used to estimate hazard ratios to compare the rate of laboratory confirmed mpox between the two groups.Results3204 men who received the vaccine were matched to 3204 unvaccinated controls. A total of 71 mpox infections were diagnosed, with 0.09 per 1000 person days (95% confidence interval (CI) 0.05 to 0.13) in the vaccinated group and 0.20 per 1000 person days (0.15 to 0.27) in the unvaccinated group over the study period of 153 days. Estimated vaccine effectiveness of one dose of MVA-BN against mpox infection was 58% (95% CI 31% to 75%).ConclusionThe findings of this study, conducted in the context of a targeted vaccination programme and evolving outbreak of mpox, suggest that one dose of MVA-BN is moderately effective in preventing mpox infection.

AbstractThe incidence of HIV infections in Canada has increased yearly since 2014. New cases of HIV have resulted almost exclusively from non-occupational exposures, including sexual contact and needle sharing. Appropriate HIV post-exposure prophylaxis is under-prescribed to patients who present to the emergency department after a high-risk exposure. In November of 2017, a Canadian guideline on HIV pre-exposure prophylaxis (PrEP) and non-occupational post-exposure prophylaxis (nPEP) was published. The guideline presents a standardized, evidence-based approach to assessing risk for HIV transmission and prescribing HIV prophylaxis. This summary highlights the key points from the guideline that are relevant to the practice of emergency medicine in Canada.

ObjectivesRates of chlamydia and gonorrhoea have been rising in urban centres in Canada, particularly among HIV-positive men who have sex with men (MSM). Our objective was to identify behavioural risk factors for diagnosis with chlamydia and gonorrhoea in this population, with a focus on the HIV status of sexual partners.MethodsThe OHTN Cohort Study follows people in HIV care across Ontario. We restricted the analysis to 1997 MSM who completed questionnaires in 2010–2013 at one of seven clinics that submit all chlamydia and gonorrhoea tests to the provincial public health laboratory; we obtained test results via record linkage. We estimated cumulative incidences using Kaplan–Meier methods and identified risk factors for diagnosis of a composite outcome (chlamydia or gonorrhoea infection) using Cox regression.ResultsAt follow-up, there were 74 new chlamydia/gonorrhoea diagnoses with a 12-month cumulative incidence of 1.7% (95% CI 1.1% to 2.2%). Risk factors for chlamydia/gonorrhoea diagnosis were: 5+ HIV-positive partners (HR=3.3, 95% CI 1.4 to 7.8; reference=none) and recreational drug use (HR=2.2, 95% CI 1.2 to 3.9).ConclusionsHeightened risks with recreational drug use and multiple HIV-positive partners suggest that chlamydia/gonorrhoea may have achieved high prevalence in certain sexual networks among HIV-positive MSM. Interventions to promote safer sex and timely testing among MSM are needed.

We report a preterm infant with congenital HIV-1, CMV, and toxoplasmosis coinfection, whose mother succumbed to probable cerebral toxoplasmosis. Despite repeated neuroimaging, retinal examinations and infant serologic tests, during the first 36 days of life, there was no evidence of congenital toxoplasmosis. However, subsequent tests showed cerebral calcifications, bilateral chorioretinitis, antitoxoplasma IgM antibody, and Toxoplasma gondiiDNA in the cerebrospinal fluid by polymerase chain reaction.