Effectiveness of mRNA COVID-19 Monovalent and Bivalent Vaccine Booster Doses Against Omicron Severe Outcomes Among Adults Aged ≥50 Years in Ontario, Canada: A Canadian Immunization Research Network Study.

We estimated the effectiveness of booster doses of monovalent and bivalent mRNA COVID-19 vaccines against Omicron-associated severe outcomes among adults aged ≥50 years in Ontario, Canada. Monovalent and bivalent mRNA COVID-19 booster doses provided similar strong initial protection against severe outcomes. Uncertainty remains around waning of protection from these vaccines.

Prevalence of Oral Human Papillomavirus Infection Among Urban Gay, Bisexual, and Other Men Who Have Sex With Men in Canada, 2017-2019.

BACKGROUND: Oral human papillomavirus (HPV) infections are a leading cause of oropharyngeal cancers. In 2015 and 2016, HPV vaccines became publicly funded for gay, bisexual, and other men who have sex with men (GBM) under 27 years of age in most Canadian provinces. METHODS: Between 2017 and 2019, sexually-active GBM in Montreal, Toronto, and Vancouver were recruited through respondent-driven sampling. Participants aged 16 to 30 years were invited to self-collect oral rinse specimens for HPV testing. We estimated HPV prevalence in the oral tract overall and compared these by vaccination status. RESULTS: Among the 838 GBM with a valid oral specimen, 36.9% reported receiving ≥1 dose of HPV vaccine. Overall, oral HPV prevalence was 2.6% (95% confidence interval, CI: 1.5, 3.7%) for at least one HPV type and 1.2% (95% CI: 0.5, 1.9%) for any high-risk type. We detected quadrivalent (HPV 6/11/16/18) vaccine-preventable types in 0.3% (95% CI: 0.0, 1.0%) of vaccinated individuals and 1.1% (95% CI: 0.1, 2.0%) in unvaccinated individuals. CONCLUSIONS: Oral HPV prevalence was low in a population of young urban GBM in Canada of whom 37% were vaccinated. Findings serve as a benchmark for monitoring of vaccination impacts on oral HPV infection within this priority population.

Effectiveness and Duration of Protection of a Fourth Dose of Coronavirus Disease 2019 Messenger RNA Vaccine Among Long-term Care Residents in Ontario, Canada.

We estimated the effectiveness of a fourth dose of messenger RNA coronavirus disease 2019 vaccine against Omicron infections and severe outcomes over time among long-term care residents in Ontario, Canada. Fourth doses provide additional protection against Omicron-related outcomes, but the protection wanes over time, with more waning seen against infection than severe outcomes.

Vaccine Effectiveness Against 12-Month Incident and Persistent Anal Human Papillomavirus Infection Among Gay, Bisexual, and Other Men Who Have Sex With Men.

BACKGROUND: Real-world evidence of human papillomavirus (HPV) vaccine effectiveness (VE) against longitudinal outcomes is lacking among gay, bisexual, and other men who have sex with men (GBM). We compared 12-month incidence and persistence of anal HPV infection between vaccinated and unvaccinated GBM. METHODS: We recruited GBM aged 16-30 years in Montreal, Toronto, and Vancouver, Canada, from 2017 to 2019. Participants were followed over a median of 12 months (interquartile range, 12-13 months). Participants self-reported HPV vaccination and self-collected anal specimens for HPV DNA testing. We calculated prevalence ratios (PR) for 12-month cumulative incidence and persistence with ≥1 quadrivalent vaccine type (HPV 6/11/16/18) between vaccinated (≥1 dose at baseline) and unvaccinated participants using a propensity score-weighted, modified Poisson regression. RESULTS: Among 248 participants, 109 (44.0%) were vaccinated at baseline, of whom 62.6% received 3 doses. PRs for HPV 6/11/16/18 were 0.56 (95% confidence interval [CI], .24-1.31) for cumulative incidence and 0.53 (95% CI, .25-1.14) for persistence. PRs were 0.23 (95% CI, .05-1.03) and 0.08 (95% CI, .01-.59) for incidence and persistence, respectively, among participants who received their first dose at age ≤23 years and 0.15 (95% CI, .03-.68) and 0.12 (95% CI, .03-.54) among participants who were sexually active for ≤5 years before vaccination. CONCLUSIONS: Findings support national recommendations for HPV vaccination at younger ages or soon after sexual debut.

Protection conferred by COVID-19 vaccination, prior SARS-CoV-2 infection, or hybrid immunity against Omicron-associated severe outcomes among community-dwelling adults.

INTRODUCTION: We assessed protection from COVID-19 vaccines and/or prior SARS-CoV-2 infection against Omicron-associated severe outcomes during successive sublineage-predominant periods. METHODS: We used a test-negative design to estimate protection by vaccines and/or prior infection against hospitalization/death among community-dwelling, PCR-tested adults aged ≥50 years in Ontario, Canada between January 2, 2022 and June 30, 2023. Multivariable logistic regression was used to estimate the relative change in the odds of hospitalization/death with each vaccine dose (2-5) and/or prior PCR-confirmed SARS-CoV-2 infection (compared with unvaccinated, uninfected subjects) up to 15 months since the last vaccination or infection. RESULTS: We included 18,526 cases with Omicron-associated severe outcomes and 90,778 test-negative controls. Vaccine protection was high during BA.1/BA.2 predominance, but was generally <50% during periods of BA.4/BA.5 and BQ/XBB predominance without boosters. A third/fourth dose transiently increased protection during BA.4/BA.5 predominance (third-dose, 6-month: 68%, 95%CI 63%-72%; fourth-dose, 6-month: 80%, 95%CI 77%-83%), but was lower and waned quickly during BQ/XBB predominance (third-dose, 6-month: 59%, 95%CI 48%-67%; 12-month: 49%, 95%CI 41%-56%; fourth-dose, 6-month: 62%, 95%CI 56%-68%, 12-months: 51%, 95%CI 41%-56%). Hybrid immunity conferred nearly 90% protection throughout BA.1/BA.2 and BA.4/BA.5 predominance, but was reduced during BQ/XBB predominance (third-dose, 6-month: 60%, 95%CI 36%-75%; fourth-dose, 6-month: 63%, 95%CI 42%-76%). Protection was restored with a fifth dose (bivalent; 6-month: 91%, 95%CI 79%-96%). Prior infection alone did not confer lasting protection. CONCLUSION: Protection from COVID-19 vaccines and/or prior SARS-CoV-2 infections against severe outcomes is reduced when immune-evasive variants/subvariants emerge and may also wane over time. Our findings support a variant-adapted booster vaccination strategy with periodic review.

Self-reported Human Papillomavirus Vaccination and Vaccine Effectiveness Among Men Who Have Sex with Men: A Quantitative Bias Analysis.

BACKGROUND: Self-report of human papillomavirus (HPV) vaccination has ~80-90% sensitivity and ~75-85% specificity. We measured the effect of nondifferential exposure misclassification associated with self-reported vaccination on vaccine effectiveness (VE) estimates. METHODS: Between 2017-2019, we recruited sexually active gay, bisexual, and other men who have sex with men aged 16-30 years in Canada. VE was derived as 1-prevalence ratio × 100% for prevalent anal HPV infection comparing vaccinated (≥1 dose) to unvaccinated men using a multivariable modified Poisson regression. We conducted a multidimensional and probabilistic quantitative bias analysis to correct VE estimates. RESULTS: Bias-corrected VE estimates were relatively stable across sensitivity values but differed from the uncorrected estimate at lower values of specificity. The median adjusted VE was 27% (2.5-97.5th simulation interval = -5-49%) in the uncorrected analysis, increasing to 39% (2.5-97.5th simulation interval = 2-65%) in the bias-corrected analysis. CONCLUSION: A large proportion of participants erroneously reporting HPV vaccination would be required to meaningfully change VE estimates.

Community and Health Care Provider Preferences for Bacterial Sexually Transmitted Infection Testing Interventions for Gay, Bisexual, and Other Men Who Have Sex With Men: e-Delphi Study.

BACKGROUND: Canadian clinical guidelines recommend at least annual and up to quarterly bacterial sexually transmitted infection (STI) testing among sexually active gay, bisexual, and other men who have sex with men (GBM). However, testing rates are suboptimal. Innovative solutions are needed to close the gap because there is currently limited knowledge on how best to approach this issue. OBJECTIVE: Our aim was to build consensus regarding interventions with the greatest potential for improving local STI testing services for GBM communities in Toronto, Ontario, Canada, using a web-based e-Delphi process. METHODS: The e-Delphi method involves using a panel format to conduct successive rounds of prioritization, with feedback between rounds, to determine priorities among groups. We recruited experts separately from the community (GBM who sought or underwent STI testing in the preceding 18 months; conducted between October 2019 and November 2019) and health care providers (those who offered STI testing to GBM in the past 12 months; conducted between February 2020 and May 2020). The experts prioritized 6 to 8 potential interventions on a 7-point Likert scale ranging from definitely not a priority to definitely a priority over 3 survey rounds and ranked their top 3 interventions. Consensus was defined as ≥60% within a ±1 response point. Summaries of responses were provided in successive rounds. We reported the percentage of a priority (encompassing somewhat a priority, a priority, and definitely a priority responses) at the end of the final round of the survey. RESULTS: Of the community experts (CEs), 84% (43/51) completed all rounds; 19% (8/43) were living with HIV; 37% (16/43) were HIV negative and on pre-exposure prophylaxis; and 42% (18/43) were HIV negative and not on pre-exposure prophylaxis. We reached consensus on 6 interventions: client reminders (41/43, 95%), express testing (38/43, 88%), routine testing (36/43, 84%), an online booking app (36/43, 84%), online-based testing (33/43, 77%), and nurse-led testing (31/43, 72%). The CEs favored convenient interventions that also maintain a relationship with their provider. Of the provider experts (PEs), 77% (37/48) completed all rounds; 59% (22/37) were physicians. Consensus was reached on the same 6 interventions (range 25/37, 68%, to 39/39, 100%) but not for provider alerts (7/37, 19%) and provider audit and feedback (6/37, 16%). Express testing, online-based testing, and nurse-led testing were prioritized by >95% (>37/39) of the PEs by the end of round 2 because of streamlined processes and decreased need to see a provider. CONCLUSIONS: Both panels were enthusiastic about innovations that make STI testing more efficient, with express testing rating highly in both the prioritizations and top 3 rankings. However, CEs preferred convenient interventions that involved their provider, whereas PEs favored interventions that prioritized patient independence and reduced patient-provider time. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/13801.

Routinized Syphilis Screening Among Men Living With Human Immunodeficiency Virus: A Stepped Wedge Cluster Randomized Controlled Trial.

BACKGROUND: We implemented an opt-out clinic-based intervention pairing syphilis tests with routine human immunodeficiency virus (HIV) viral load testing. The primary objective was to determine the degree to which this intervention increased the detection of early syphilis. METHODS: The Enhanced Syphilis Screening Among HIV-Positive Men (ESSAHM) Trial was a stepped wedge cluster-randomized controlled trial involving 4 urban HIV clinics in Ontario, Canada, from 2015 to 2017. The population was HIV-positive adult males. The intervention was standing orders for syphilis serological testing with viral loads, and control was usual practice. We obtained test results via linkage with the centralized provincial laboratory and defined cases using a standardized clinical worksheet and medical record review. We employed a generalized linear mixed model with a logit link to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of the intervention. RESULTS: A total of 3895 men were followed over 7471 person-years. The mean number of syphilis tests increased from 0.53 to 2.02 tests per person per year. There were 217 new diagnoses of syphilis (control, 81; intervention, 136), for which 147 (68%) were cases of early syphilis (control, 61 [75%]; intervention, 86 [63%]). The annualized proportion with newly detected early syphilis increased from 0.009 to 0.032 with implementation of the intervention; the corresponding time-adjusted OR was 1.25 (95% CI, .71-2.20). CONCLUSIONS: The implementation of standing orders for syphilis testing with HIV viral loads was feasible and increased testing, yet produced less-than-expected increases in case detection compared to past uncontrolled pre-post trials. CLINICAL TRIALS REGISTRATION: NCT02019043.

Low human papillomavirus vaccine uptake among women engaged in HIV care in Ontario, Canada.

Women living with HIV are at higher risk for human papillomavirus (HPV)-related dysplasia and cancers and thus are prioritized for HPV vaccination. We measured HPV vaccine uptake among women engaged in HIV care in Ontario, Canada, and identified socio-demographic, behavioural, and clinical characteristics associated with HPV vaccination. During annual interviews from 2017 to 2020, women participating in a multi-site, clinical HIV cohort responded to a cross-sectional survey on HPV vaccine knowledge and receipt. We used logistic regression to derive age-adjusted odds ratios and 95% confidence intervals (CI) for factors associated with self-reported vaccine initiation (≥1 dose) or series completion (3 doses). Among 591 women (median age = 48 years; interquartile range = 40-56 years), 13.2% (95%CI = 10.5-15.9%) had received ≥1 dose. Of those vaccinated, 64.6% had received 3 doses. Vaccine initiation (≥1 dose) was significantly higher among women aged 20-29 years at 31.0% but fell to 13.9% in those aged 30-49 years and < 10% in those aged ≥50 years. After age adjustment, vaccine initiation was significantly associated with being employed (vs. unemployed but seeking work), income $40,000-$59,999 (vs. <$20,000), being married/common-law (vs. single), living with children, immigrating to Canada >5 years ago (vs. immigrating ≤5 years ago), never smoking (vs. currently smoking), and being in HIV care longer (per 10 years). Similar factors were identified for series completion (3 doses). HPV vaccine uptake remains low among women living with HIV in our cohort despite regular engagement in care. Recommendations for improving uptake include education of healthcare providers, targeted community outreach, and public funding of HPV vaccination.

Influence of previous experience with and beliefs regarding anal cancer screening on willingness to be screened among men living with HIV.

BACKGROUND: Implementation of anal cancer screening requires the procedure to be acceptable to the target population. Our objective was to assess the beliefs of men living with HIV regarding anal cancer screening and identify factors associated with their willingness to participate in screening. METHODS: We developed a cross-sectional questionnaire using the Theory of Planned Behavior to examine beliefs regarding prevention of human papillomavirus (HPV)-related diseases, administered to men living with HIV in 2016-2017 in a multi-site HIV clinical cohort. Correspondence analysis was used to examine the interrelationships between men's beliefs and willingness to undergo anal cancer screening. We used multivariable proportional odds models to identify factors associated with increasing willingness. Results were reported as adjusted odds ratios (aOR) with 95% confidence intervals (CI). RESULTS: Among 1677 male participants, the vast majority (90%) would be willing to undergo screening by "anal Pap test"; willingness clustered with positive beliefs (e.g. confident they can get screened; disagree that they will feel pain) in the correspondence analysis. Higher self-perceived risk for anal cancer and positive beliefs regarding screening were associated with higher willingness to be screened. Gay, bisexual and other men who have sex with men had higher willingness (aOR = 1.62; 95% CI: 1.15, 2.29) than heterosexual men. Racialized men reported lower willingness (aOR = 0.68; 95% CI: 0.54, 0.89) than white men. CONCLUSIONS: Men generally had positive beliefs and were willing to undergo screening, though there were differences by sexual orientation and racial identity. Tailored community-led initiatives could focus on men's understanding of their risk and expectations of anal cancer screening to facilitate participation.

Survey of Health Care Providers' Practices and Opinions Regarding Bacterial Sexually Transmitted Infection Testing Among Gay, Bisexual, and Other Men Who Have Sex With Men.

BACKGROUND: Rates of bacterial sexually transmitted infections (STIs) continue to rise among gay, bisexual, and other men who have sex with men (GBMSM) globally. Testing and treatment can prevent morbidity and transmission. However, testing rates remain suboptimal. METHODS: In 2018, we conducted an online cross-sectional survey to explore STI testing ordering practices, 14 potential barriers for testing and 11 possible ways to improve testing from the perspective of health care providers in Toronto, Ontario. An estimated 172 providers were invited from primary care and sexual health clinic settings. Providers were eligible to complete the survey if they provided care for ≥1 GBMSM per week and were involved in the decision-making process in providing STI tests. We used descriptive statistics to summarize survey responses. RESULTS: Ninety-five providers (55% response rate) participated, of whom 68% worked in primary care and 32% in sexual health settings. Most (66%) saw ≤10 GBMSM clients per week. In primary care (65%) and sexual health (40%) clinic settings, insufficient consultation time was the most common barrier to STI testing. In primary care, other common barriers included difficulty introducing testing during unrelated consultations (53%), forgetting (47%), and patients being sexually inactive (31%) or declining testing (27%). The following were most likely to improve testing: express/fast-track testing services (89%), provider alerts when patients are due for testing (87%), patient-collected specimens (84%), nurse-led STI testing (79%), and standing orders (79%). CONCLUSIONS: Promising interventions to improve bacterial STI testing included initiatives that simplify and expedite testing and expand testing delivery to other health care professionals.

Low human papillomavirus (HPV) vaccine uptake among men living with human immunodeficiency virus (HIV): Cross-sectional findings from a clinical cohort.

Men living with human immunodeficiency virus (HIV) are internationally recognized as a priority population for human papillomavirus (HPV) vaccination. Our objective was to explore HPV vaccine uptake among men living with HIV in Ontario, Canada, and investigate differences between vaccinated and unvaccinated men. We used data from a cross-sectional questionnaire administered between 2016 and 2017 among men living with HIV and participating in the Ontario HIV Treatment Network Cohort Study. We calculated the proportion vaccinated against HPV, described vaccination experiences, and HPV vaccine knowledge, and calculated differences in characteristics between vaccinated and unvaccinated men. Among 1651 men (mean age = 51 years, 72% identified as gay), 7% were vaccinated (95% confidence interval[CI] 5.5-7.9%); 85% received their first dose at a primary care or HIV clinic. Among unvaccinated men, 40% were unaware of the HPV vaccine, 65% reported low perceived risk for HPV, and 8% discussed HPV vaccination with a physician. Compared to unvaccinated men, vaccinated men were younger, most identified as gay, had a higher education/income, reported a higher number of recent sex partners, and had a history of bacterial sexually transmitted infections (STIs), HPV, anogenital warts, and/or anal cancer. Our findings reveal that few men living with HIV were vaccinated against HPV. This may be influenced by low HPV awareness, prohibitive cost, and lack of physician recommendation. Several men reporting lower socio-economic status, older men, and heterosexual, bisexual, and other men who have sex with men were missed for vaccination. Primary care and HIV clinics may be ideal locations to increase uptake.

Patient perspectives on the implementation of routinised syphilis screening with HIV viral load testing: Qualitative process evaluation of the Enhanced Syphilis Screening Among HIV-positive Men trial.

BACKGROUND: Syphilis infections have been on the rise, affecting men living with HIV in urban centres disproportionately. Since individuals in HIV care undergo routine blood testing, HIV clinics provide practical opportunities to conduct regular and frequent syphilis testing. Following the implementation of a routine syphilis testing intervention in HIV outpatient clinics, we conducted a qualitative process evaluation of patient experiences to measure patient acceptability, barriers to implementation, and facilitators of successful uptake. METHODS: Upon completion of the trial, which took place at four HIV outpatient clinics in Toronto and Ottawa, Canada, we recruited male patients attending these clinics from November 2017 to April 2018. Interviews were conducted on-site and were audio-recorded and transcribed verbatim. All participants provided written informed consent. Interview data were analyzed using grounded theory, assessing qualitative modulators of effective uptake of routinised syphilis testing. RESULTS: A total of 21 male patients were interviewed. Overall, interviewees found the clinical intervention acceptable, endorsing the practice of routinising syphilis testing alongside regular viral load bloodwork. Some men preferred, based on their self-assessment of syphilis risk, to opt out of testing; we considered this as a potential barrier to uptake of population-wide routinised syphilis testing. Interviewees also identified multiple facilitators of successful uptake, including the de-stigmatising of STI testing as a consequence of the universal nature of routinised testing. Participants recommended a routinised syphilis screening intervention to give patients peace of mind surrounding their sexual health. Participants identified HIV care clinics as comfortable and efficient locations to offer testing. CONCLUSIONS: Overall, most men were in support of implementing routinised syphilis testing as part of standard HIV care. From the patient perspective, HIV care clinics are convenient places to be tested for syphilis, and the routine approach was viewed to have a de-stigmatisng effect on syphilis testing. TRIAL REGISTRATION: ClinicalTrials.gov NCT02019043; registered December 23, 2013.

Low human papillomavirus (HPV) knowledge related to low risk perception among men living with HIV: Implications for HPV-associated disease prevention.

Human papillomavirus (HPV)-associated anal cancer is orders of magnitude higher among men living with HIV than the general male population. Our objective was to examine factors associated with HPV awareness and self-perceived risk for HPV-associated anal cancer among men living with HIV, which may influence uptake of cancer prevention strategies. A cross-sectional questionnaire on HPV was administered from 2016 to 2017 to 1677 men in a multisite, HIV clinical cohort in Ontario, Canada. We used logistic regression and proportional odds models to identify factors associated with being familiar with HPV and increasing self-perceived risk for anal cancer, respectively. We used correspondence analysis to examine associations of specific HPV-related knowledge with self-perceived risk. Only 52% were familiar with HPV, and 72% felt they had no or low risk for anal cancer. Familiarity with HPV was more common among men who have sex with men than heterosexual men (58% vs. 21%). Older men were less likely to be familiar with HPV (adjusted odds ratio [aOR] per 10 years = 0.77; 95% confidence interval [CI]: 0.69, 0.85). Familiarity with HPV was associated with increasing self-perceived risk (aOR = 2.39; 95% CI: 1.87, 3.04). After accounting for differences in HPV awareness and sexual orientation, racialized men had lower self-perceived risk (aOR = 0.68; 95% CI: 0.52, 0.88). In the correspondence analysis, risk-focused HPV-related knowledge (e.g., knowing smoking increases risk) was associated with highest risk perception. Efforts are needed to improve HPV-related health literacy in this population. Our findings suggest specific HPV-related knowledge may differentially influence self-perceived risk for anal cancer.

Economic barriers, evidentiary gaps, and ethical conundrums: a qualitative study of physicians' challenges recommending HPV vaccination to older gay, bisexual, and other men who have sex with men.

BACKGROUND: The human papillomavirus (HPV) is the most common sexually transmitted infection (STI) worldwide. Gay, bisexual, and other men who have sex with men (GBM), and GBM living with HIV in particular, are disproportionately impacted by HPV-associated cancers. The HPV vaccine, given early enough in life, may markedly reduce the likelihood of such cancers. In Canada, most provincial insurance programs only cover HPV vaccination for GBM up to the age of 26. Our objective was to understand physicians' everyday experiences and challenges in recommending HPV vaccination to older GBM patients. METHODS: As part of the HPV Screening and Vaccine Evaluation (HPV-SAVE) Study, we conducted semi-structured interviews with 25 HIV-positive GBM patients who had received anal cancer screening and 15 service providers, including 13 physicians, who had arranged for anal cancer screening in the Canadian provinces of Ontario and British Columbia. In this analysis, we draw upon the 13 physician interviews, which were coded following Grounded Theory. RESULTS: Physicians strongly supported the HPV vaccine for all GBM and considered it to be important for the management of HIV-related care. However, the overall support for HPV vaccination among physicians did not translate into consistent recommendation practices. There were two overarching factors that limited the strength/frequency of physicians' vaccine recommendation practices. First, cost/insurance coverage for some older patients impacted if and how the HPV vaccine was discussed. Second, physicians had diverse perspectives on both the prevention and therapeutic benefits of vaccinating older GBM and the reality that national guidelines are incongruent with publicly funded vaccine programs for vaccinating patients over 26 years old. These two interrelated factors have co-produced an apparent economic-evidentiary conundrum for many physicians regarding how and for whom to offer HPV vaccination. CONCLUSION: Economic barriers coupled with evidentiary and guideline gaps have created clinical practice challenges for physicians and has resulted in different messages being communicated to some older GBM patients about how important HPV vaccination is for their health.

Serosorting and recreational drug use are risk factors for diagnosis of genital infection with chlamydia and gonorrhoea among HIV-positive men who have sex with men: results from a clinical cohort in Ontario, Canada.

OBJECTIVES: Rates 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. METHODS: The 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. RESULTS: At 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). CONCLUSIONS: Heightened 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.

High incidence of diagnosis with syphilis co-infection among men who have sex with men in an HIV cohort in Ontario, Canada.

BACKGROUND: The re-emergence of syphilis among HIV-positive gay and other men who have sex with men (MSM) requires vigilance. We estimated incidence of and risk factors for first and subsequent syphilis diagnoses among MSM in HIV care in Ontario, Canada. METHODS: We analyzed data from 2,280 MSM under follow-up from 2006 to 2010 in the Ontario HIV Treatment Network Cohort Study (OCS), a multi-site clinical cohort. We obtained syphilis serology results via record linkage with the provincial public health laboratory. Rates were calculated using Poisson regression. RESULTS: First syphilis diagnoses occurred at a rate of 2.0 per 100 person-years (95 % CI 1.7, 2.4; 121 cases) whereas the re-diagnosis rate was 7.5 per 100 person-years (95 % CI 6.3, 8.8; 136 cases). We observed higher rates over time and among men who were aged <30 years, receiving care in the two largest urban centers, or had a previous syphilis diagnosis. Syphilis diagnosis was less common among Indigenous men, men with higher CD4 cell counts, and, for first diagnoses only, among men with less than high school education. CONCLUSIONS: Compared to reported cases in the general male population, incidence of a new syphilis diagnosis was over 300 times greater among HIV-positive MSM but year-to-year changes reflected provincial trends. Re-diagnosis was common, suggesting treatment failure or re-infection. Novel syphilis control efforts are needed among HIV-positive MSM.

Modest rise in chlamydia and gonorrhoea testing did not increase case detection in a clinical HIV cohort in Ontario, Canada.

OBJECTIVES: We described patterns of testing for chlamydia and gonorrhoea infection among persons in specialty HIV care in Ontario, Canada, from 2008 to 2011. METHODS: We analysed data from 3165 participants in the OHTN Cohort Study attending one of seven specialty HIV care clinics. We obtained chlamydia and gonorrhoea test results via record linkage with the provincial public health laboratory. We estimated the proportion of participants who underwent testing annually, the positivity rate among those tested and the proportion diagnosed with chlamydia or gonorrhoea among all under observation. We explored risk factors for testing and diagnosis using multiple logistic regression analysis. RESULTS: The proportion tested annually rose from 15.2% (95% CI 13.6% to 16.7%) in 2008 to 27.0% (95% CI 25.3% to 28.6%) in 2011 (p<0.0001). Virtually all were urine-based nucleic acid amplification tests. Testing was more common among men who have sex with men (MSM), younger adults, Toronto residents, persons attending primary care clinics and persons who had tested in the previous year or who had more clinic visits in the current year. We observed a decrease in test positivity rates over time. However, the annual proportion diagnosed remained stable and in 2011 this was 0.97% (95% CI 0.61% to 1.3%) and 0.79% (95% CI 0.46% to 1.1%) for chlamydia and gonorrhoea, respectively. Virtually all cases were among MSM. CONCLUSIONS: Chlamydia and gonorrhoea testing increased over time while test positivity rates declined and the overall proportion diagnosed remained stable, suggesting that the modest increase in testing did not improve case detection.

Invasive Pneumococcal Disease Epidemiology and Serotype Replacement After the Introduction of the 13-Valent Pneumococcal Conjugate Vaccine in Ontario, Canada, 2007-2022.

Background: New vaccine products were recently authorized for protection against invasive pneumococcal disease (IPD) in Canada. Our aim was to determine age- and serotype-specific trends in IPD incidence and severity in Canada's largest province, Ontario. Methods: We included all confirmed IPD cases reported in Ontario and defined the pre-pneumococcal 13-valent conjugate vaccine (PCV13) era (01/2007 to 12/2010), post-PCV13 era (01/2011 to 12/2019), and coronavirus disease 2019 (COVID-19) pandemic era (01/2020 to 12/2022). We estimated incidence, hospitalization, and case fatality rate (CFR) by age. We grouped IPD cases by vaccine-specific serotypes (PCV13; PCV15-non-PCV13; PCV20-non-PCV13; PCV20-non-PCV15; polysaccharide 23-valent vaccine-non-PCV20; and non-vaccine-preventable [NVP]). We then compared incidence rates by age and serotype group in the pre- and post-PCV13 eras by calculating rate ratios (RRs) and their 95% CIs. Results: Incidence and hospitalizations declined from the pre- to post-PCV13 era in children aged <5 years (RR, 0.7; 95% CI, 0.6-0.8; and RR, 0.8; 95% CI, 0.7-0.9, respectively), but the CFR increased (1.4% to 2.3%). Other age groups saw smaller declines or more stable incidence rates across the years; hospitalizations increased in adults aged 50-64 years (RR, 1.2; 95% CI, 1.1-1.4) and ≥65 years (RR, 1.1; 95% CI, 1.0-1.1). For all ages, IPD cases and hospitalizations attributable to PCV13 serotypes declined, and those attributable to PCV15-non-PCV13, PCV20-non-PCV13, and NVP serotypes increased. IPD incidence declined during the COVID-19 era. Conclusions: IPD incidence and hospitalizations due to PCV13 serotypes decreased after PCV13 introduction but increased for other serotypes. Continued surveillance is required to evaluate changes to pneumococcal vaccination programs and ongoing changes to the distribution of IPD-causing serotypes.

Effectiveness of mRNA COVID-19 vaccine booster doses against Omicron severe outcomes.

We estimated the effectiveness of booster doses of monovalent mRNA COVID-19 vaccines against Omicron-associated severe outcomes among adults in Ontario, Canada. We used a test-negative design to estimate vaccine effectiveness (VE) against hospitalization or death among SARS-CoV-2-tested adults aged ≥50 years from January 2 to October 1, 2022, stratified by age and time since vaccination. We also compared VE during BA.1/BA.2 and BA.4/BA.5 sublineage predominance. We included 11,160 cases and 62,880 tests for test-negative controls. Depending on the age group, compared to unvaccinated adults, VE was 91-98% 7-59 days after a third dose, waned to 76-87% after ≥240 days, was restored to 92-97% 7-59 days after a fourth dose, and waned to 86-89% after ≥120 days. VE was lower and declined faster during BA.4/BA.5 versus BA.1/BA.2 predominance, particularly after ≥120 days. Here we show that booster doses of monovalent mRNA COVID-19 vaccines restored strong protection against severe outcomes for at least 3 months after vaccination. Across the entire study period, protection declined slightly over time, but waned more during BA.4/BA.5 predominance.