Impact of screening and doxycycline prevention on the syphilis epidemic among men who have sex with men in British Columbia: a mathematical modelling study.

Background: Men who have sex with men (MSM) in British Columbia (BC) are disproportionately affected by infectious syphilis and HIV. In this study, we developed a co-interaction model and evaluated the impact and effectiveness of possible interventions among different MSM subgroups on the syphilis epidemic. Methods: We designed a deterministic compartmental model, which stratified MSM by HIV status and HIV pre-exposure prophylaxis (HIV-PrEP) usage into (1) HIV-negative/unaware MSM (HIV-PrEP not recommended, not on HIV-PrEP), (2) HIV-negative/unaware MSM with HIV-PrEP recommended (not on HIV-PrEP), (3) HIV-negative/unaware MSM actively on HIV-PrEP, and (4) MSM diagnosed with HIV. We estimated the effect of scaling up syphilis testing frequency from Status Quo to six-, four-, and three-months, increasing the percentage of MSM using doxycycline prevention (Doxy-P) to 25%, 50%, and 100% of the target level, and a combination of both among subgroups (2)-(4). We also assessed the impact of these interventions on the syphilis incidence rates from 2020 to 2034 in comparison to the Status Quo scenario where no intervention was introduced. Findings: Under the Status Quo scenario, with the expansion of the HIV-PrEP program to improve syphilis testing, the syphilis incidence rate was estimated to peak at 16.1 [Credible Interval (CI):14.2-17.9] per 1,000 person-years (PYs) in 2023 and decrease to 6.7 (CI:3.8-10.9) per 1,000 PYs by 2034. The syphilis incidence rate in 2034 was estimated at 0.7 (0.3-1.3) per 1,000 PYs if MSM diagnosed with HIV could be tested every four months, and at 1.5 (0.7-3.0) per 1,000 PYs if HIV-negative/unaware MSM actively on HIV-PrEP could be tested every three months. By achieving 100% of the target coverage of Doxy-P, the syphilis incidence rate was estimated at 1.4 (0.5-3.4) if focusing on MSM diagnosed with HIV, and 2.6 (1.2-5.1) per 1,000 PYs if focusing on HIV-negative/unaware MSM actively on HIV-PrEP. Under the combined interventions, the syphilis incidence rate could be as low as 0.0 (0.0-0.1) and 0.8 (0.3-1.8) per 1,000 PYs, respectively. Interpretation: The HIV-PrEP program in BC plays a crucial role in increasing syphilis testing frequency among high-risk MSM and reducing syphilis transmission among this group. In addition, introducing Doxy-P can be an effective complementary strategy to minimize syphilis incidence, especially among MSM diagnosed with HIV. Funding: This work was funded by the Canadian Institutes of Health Research.

The Resurgence of Lymphogranuloma Venereum: Changing Presentation of Lymphogranuloma Venereum in the Era of HIV Preexposure Prophylaxis, 2004 to 2022.

BACKGROUND: Before the early 2000s, the sexually transmitted infection lymphogranuloma venereum (LGV) was rare in high-income countries. Initially, most cases in these countries were among symptomatic men who have sex with men (MSM) living with HIV. In the context of widespread HIV preexposure prophylaxis (PrEP), LGV's epidemiology may be changing. We aimed to characterize the epidemiology and clinical presentation of LGV in the PrEP era. METHODS: A retrospective chart review was performed on all LGV cases occurring between November 2004 to October 2022 in British Columbia (BC), Canada. Cases were stratified by having occurred before (2004-2017) or after widespread PrEP availability in BC (2018-2022). Annual rates and test positivity percentages were calculated. Bivariate logistic regression was performed to identify drivers of asymptomatic infection in the PrEP era. RESULTS: Among 545 cases identified, 205 (37.6%) occurred pre-PrEP and 340 (62.4%) occurred during the PrEP era. Most cases were among MSM (97.2%). The estimated rate of LGV has doubled from 2018 to 2022, reaching 1535.2 cases per 100,000 PrEP users. Most PrEP-era cases were among HIV-negative individuals (65.3%), particularly those on PrEP (72.6%). Cases in the PrEP era were often asymptomatic compared with pre-PrEP (38.6% vs. 19.3%; P < 0.001). Users of PrEP were more likely to experience asymptomatic infection compared with HIV-negative PrEP nonusers (odds ratio, 2.07; 95% confidence interval, 1.07-3.99). CONCLUSIONS: In the context of increased asymptomatic testing, LGV may be increasing in BC. Most infections now occur among HIV-negative MSM. A high proportion of infections are asymptomatic.

COVID-19 vaccine effectiveness by HIV status and history of injection drug use: a test-negative analysis.

INTRODUCTION: People living with HIV (PLWH) and/or who inject drugs may experience lower vaccine effectiveness (VE) against SARS-CoV-2 infection. METHODS: A validated algorithm was applied to population-based, linked administrative datasets in the British Columbia COVID-19 Cohort (BCC19C) to ascertain HIV status and create a population of PLWH and matched HIV-negative individuals. The study population was limited to individuals who received an RT-PCR laboratory test for SARS-CoV-2 between 15 December 2020 and 21 November 2021 in BC, Canada. Any history of injection drug use (IDU) was ascertained using a validated administrative algorithm. We used a test-negative study design (modified case-control analysis) and multivariable logistic regression to estimate adjusted VE by HIV status and history of IDU. RESULTS: Our analysis included 2700 PLWH and a matched population of 375,043 HIV-negative individuals, among whom there were 351 and 103,049 SARS-CoV-2 cases, respectively. The proportion of people with IDU history was much higher among PLWH compared to HIV-negative individuals (40.7% vs. 4.3%). Overall VE during the first 6 months after second dose was lower among PLWH with IDU history (65.8%, 95% CI = 43.5-79.3) than PLWH with no IDU history (80.3%, 95% CI = 62.7-89.6), and VE was particularly low at 4-6 months (42.4%, 95% CI = -17.8 to 71.8 with IDU history vs. 64.0%; 95% CI = 15.7-84.7 without), although confidence intervals were wide. In contrast, overall VE was 88.6% (95% CI = 88.2-89.0) in the matched HIV-negative population with no history of IDU and remained relatively high at 4-6 months after second dose (84.6%, 95% CI = 83.8-85.4). Despite different patterns of vaccine protection by HIV status and IDU history, peak estimates were similar (≥88%) across all populations. CONCLUSIONS: PLWH with a history of IDU may experience lower VE against COVID-19 infection, although findings were limited by a small sample size. The lower VE at 4-6 months may have implications for booster dose prioritization for PLWH and people who inject drugs. The immunocompromising effect of HIV, substance use and/or co-occurring comorbidities may partly explain these findings.

Risk of COVID-19 hospitalization in people living with HIV and HIV-negative individuals and the role of COVID-19 vaccination: A retrospective cohort study.

OBJECTIVE: To examine the risk of hospitalization within 14 days of COVID-19 diagnosis among people living with HIV (PLWH) and HIV-negative individuals who had laboratory-confirmed SARS-CoV-2 infection. METHODS: We used Cox proportional hazard models to compare the relative risk of hospitalization in PLWH and HIV-negative individuals. Then, we used propensity score weighting to examine the influence of sociodemographic factors and comorbid conditions on risk of hospitalization. These models were further stratified by vaccination status and pandemic period (pre-Omicron: December 15, 2020, to November 21, 2021; Omicron: November 22, 2021, to October 31, 2022). RESULTS: The crude hazard ratio (HR) for risk of hospitalization in PLWH was 2.44 (95% confidence interval [CI]: 2.04-2.94). In propensity score-weighted models that included all covariates, the relative risk of hospitalization was substantially attenuated in the overall analyses (adjusted HR [aHR]: 1.03; 95% CI: 0.85-1.25), in vaccinated (aHR 1.00; 95% CI: 0.69-1.45), inadequately vaccinated (aHR: 1.04; 95% CI: 0.76-1.41) and unvaccinated individuals (aHR: 1.15; 95% CI: 0.84-1.56). CONCLUSION: PLWH had about two times the risk of COVID-19 hospitalization than HIV-negative individuals in crude analyses which attenuated in propensity score-weighted models. This suggests that the risk differential can be explained by sociodemographic factors and history of comorbidity, underscoring the need to address social and comorbid vulnerabilities (e.g., injecting drugs) that were more prominent among PLWH.

Evaluating the Impact of the COVID-19-Related Public Health Restrictions on Access to Digital Sexually Transmitted and Blood-Borne Infection Testing in British Columbia, Canada: An Interrupted Time Series Analysis.

BACKGROUND: Evidence of long-term impacts of COVID-19-related public health restrictions on digital sexually transmitted and blood-borne infection (STBBI) testing utilization is limited. We assessed these impacts on GetCheckedOnline (a digital testing resource for STBBIs) relative to all STBBI tests in British Columbia (BC). METHODS: Interrupted time series analyses were conducted using GetCheckedOnline program data comparing monthly test episodes (STBBI tests per requisition) among BC residents, stratified by BC region, and testers' sociodemographic and sexual risk profiles, for the prepandemic (March 2018-February 2020) and pandemic periods (March 2020-October 2021). Trends in GetCheckedOnline testing per 100 STBBI tests in BC regions with GetCheckedOnline were analyzed. Each outcome was modeled using segmented generalized least squared regression. RESULTS: Overall, 17,215 and 22,646 test episodes were conducted in the prepandemic and pandemic periods. Monthly GetCheckedOnline test episodes reduced immediately after restrictions. By October 2021 (end of the pandemic period), monthly GetCheckedOnline testing increased by 21.24 test episodes per million BC residents (95% confidence interval, -11.88 to 54.84), and GetCheckedOnline tests per 100 tests in corresponding BC regions increased by 1.10 (95% confidence interval, 0.02 to 2.17) above baseline trends. After initial increases among users at higher STBBI risk (symptomatic testers/testers reporting sexual contacts with STBBIs), testing decreased below baseline trends later in the pandemic, whereas monthly GetCheckedOnline testing increased among people 40 years or older, men who have sex with men, racialized minorities, and first-time testers via GetCheckedOnline. CONCLUSIONS: Sustained increases in utilization of digital STBBI testing during the pandemic suggest fundamental changes in STBBI testing in BC, highlighting the need for accessible and appropriate digital testing, especially for those most affected by STBBIs.

Uptake of Mpox vaccination among transgender people and gay, bisexual and other men who have sex with men among sexually-transmitted infection clinic clients in Vancouver, British Columbia.

OBJECTIVES: As the primary public health strategy for controlling the 2022 Mpox outbreak, it is critical to evaluate the impact of Mpox vaccination campaigns for transgender people and gay, bisexual and other men who have sex with men (T/GBM). We measured vaccine uptake and associated factors among T/GBM clients of an urban STI clinic in British Columbia (BC). METHODS: We conducted a cross-sectional online survey between August 8-22, 2022 of clients who had attended the STI clinic, 5-7 weeks following the first-dose Mpox vaccination campaign in BC. We drew on a systematic review of factors associated with vaccine uptake to develop survey questions, and measured vaccine uptake among vaccine-eligible T/GBM. RESULTS: Overall, 51% of T/GBM had received the first dose of the vaccine. The sample (331 participants) was majority White and university educated, identified as a man and gay, 10% had trans experience, and 68% met eligibility criteria for vaccination. Among vaccine-eligible participants identifying as T/GBM, 66% had been vaccinated; being unvaccinated was more common among participants identifying as bisexual or heteroflexible/mostly straight, and who spent less time with other T/GBM. Eligible yet unvaccinated participants had lower perceived susceptibility, and reported fewer cues to action (e.g., fewer saw information promoting the vaccine), and increased constraints to vaccine access; vaccine barriers related to accessing clinics and privacy were common. The majority (85%) of those eligible and unvaccinated at time of survey were willing to receive the vaccine. CONCLUSION: In this sample of STI clinic clients, vaccine uptake among eligible T/GBM was high in the initial weeks following a Mpox vaccination campaign. However, uptake was patterned on social gradients with lower uptake among T/GBM who may be less effectively engaged by available promotion channels. We recommend early, intentional and diverse engagement of T/GBM populations in Mpox and other targeted vaccination programs.

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.

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.

Treatment and Partner Notification Outcomes for Clients Diagnosed With Chlamydia and Gonorrhea Through GetCheckedOnline Compared With Sexually Transmitted Infection Clinics in British Columbia, Canada.

Whether treatment, engagement in partner notification (PN), and PN outcomes differ between clients of Internet-based and clinic-based testing services is poorly understood. We compared these outcomes between people diagnosed with chlamydia and/or gonorrhea (CT/GC) through a sexually transmitted infection (STI) clinic service and GetCheckedOnline (GCO), an Internet-based testing service in British Columbia. We conducted a retrospective matched cohort study among CT/GC cases where each case diagnosed through GCO in 2016 to 2017 was matched to 2 STI clinic cases by diagnosis, sex, age group, and specimen collection date. Data were collected through chart review, with outcomes compared using appropriate statistical tests. Of 257 GCO and 514 matched clinic cases, case treatment was high and did not differ between GCO (254 of 257 [98.9%]) and clinic (513 of 514 [99.8%]) cases, as was engagement in PN (250 of 257 [97.2%] vs. 496 of 514 [96.5%]). There was no difference in the proportion of notified partners between GCO (159 of 270 [58.9%]) and clinic (253 of 435 [58.2%]) cases, although a greater proportion of partners reported by clinic cases were notified by STI nurses (43 of 435 [9.9%]) versus GCO cases (6 of 270 [2.2%]). GetCheckedOnline clients diagnosed with CT/GC demonstrated similar treatment uptake and engagement in PN to clinic clients, and PN outcomes did not differ. The greater reliance on STI clinic nurses for PN among clinic clients may be related to having had an initial in-person testing visit.

Effectiveness of COVID-19 vaccines in people living with HIV in British Columbia and comparisons with a matched HIV-negative cohort: a test-negative design.

OBJECTIVES: We estimated the effectiveness of COVID-19 vaccines against laboratory-confirmed SARS-CoV-2 infection among people living with HIV (PLWH) and compared the estimates with a matched HIV-negative cohort. METHODS: We used the British Columbia COVID-19 Cohort, a population-based data platform, which integrates COVID-19 data on SARS-CoV-2 tests, laboratory-confirmed cases, and immunizations with provincial health services data. The vaccine effectiveness (VE) was estimated with a test-negative design using the multivariable logistic regression. RESULTS: The adjusted VE against SARS-CoV-2 infection was 71.1% (39.7, 86.1%) 7-59 days after two doses, rising to 89.3% (72.2, 95.9%) between 60 and 89 days. VE was preserved 4-6 months after the receipt of two doses, after which noticeable waning was observed (51.3% [4.8, 75.0%]). In the matched HIV-negative cohort (n = 375,043), VE peaked at 91.4% (90.9, 91.8%) 7-59 days after two doses and was sustained for up to 4 months, after which evidence of waning was observed, dropping to 84.2% (83.4, 85.0%) between 4 and 6 months. CONCLUSION: The receipt of two COVID-19 vaccine doses was effective against SARS-CoV-2 infection among PLWH pre-Omicron. VE estimates appeared to peak later in PLWH than in the matched HIV-negative cohort and the degree of waning was relatively quicker in PLWH; however, peak estimates were comparable in both populations.

Examining the impacts of a syphilis awareness campaign among gay, bisexual, and other men who have sex with men (gbMSM) in British Columbia, Canada.

OBJECTIVES: Syphilis rates have increased in BC and disproportionately affect gay, bisexual, and other men who have sex with men (gbMSM). A social marketing campaign (Syphistory) ran from January to September 2017 with the primary goal of increasing syphilis knowledge and a secondary goal of increasing syphilis screening among gbMSM in BC. METHODS: We used pre- and post-campaign surveys to assess changes in syphilis knowledge from a convenience sample of clients attending STI clinics using one-sided t-tests. We used online Piwik metrics to examine the campaign reach, and provincial testing data to examine trends in syphilis screening. We used data from the Engage Study to examine factors associated with campaign awareness and associations with syphilis testing. RESULTS: Of the 2155 visitors to the Syphistory website with known geography, 79.4% were from BC. Moreover, STI clinic participants who saw the campaign demonstrated a greater knowledge of syphilis (9.7/12, 80.8%) than those who did not see the campaign (mean 8.9/12, 74%) (p < 0.001). Provincial syphilis testing rates were 8764 and 9749 in the 12 months before and after the campaign; however, we did not find an overall trend in testing before versus after the campaign (p = 0.147). Among Engage participants, 12.7% reported seeing the campaign and we found an association between campaign exposure and recent syphilis testing (aOR = 2.73; 95% CI = 1.51, 4.93). CONCLUSION: gbMSM who saw the campaign were more likely to report being tested for syphilis in the previous 6 months. STI clinic attendees who reported seeing the campaign also had higher syphilis knowledge compared to those who did not.

RéSUMé: OBJECTIFS: Les taux de syphilis ont augmenté en Colombie-Britannique et affectent de manière disproportionnée les hommes gais, bisexuels et autres hommes ayant des relations sexuelles avec des hommes (gbHARSAH). Une campagne de marketing social (Syphistory) a été mené de janvier à septembre 2017 avec pour objectif principal d'informer sur la syphilis et pour objectif secondaire d'augmenter le dépistage de la syphilis chez les gbHARSAH en Colombie-Britannique. MéTHODES: Nous avons réalisé deux sondages, l'un avant et l'autre après la campagne, sur un échantillon de convenance constitué de patients fréquentant des cliniques ITS, pour évaluer les changements dans les connaissances sur la syphilis à l'aide de tests t unilatéraux. Nous avons utilisé les mesures Piwik en ligne pour examiner la portée de la campagne et les données provinciales sur les tests pour examiner les tendances quant au dépistage de la syphilis. Nous avons utilisé les données de l'étude Engage à Vancouver, pour identifier les facteurs associés à la sensibilisation lors de la campagne et les associations avec le dépistage de la syphilis. RéSULTATS: Sur les 2 155 visiteurs du site Web Syphistory dont la position géographique était connue, 79,4 % provenaient de la Colombie-Britannique. De plus, les participants aux cliniques ITS ayant vu la campagne ont démontré une meilleure connaissance de la syphilis (9,7/12, 80,8 %) par rapport à ceux n'ayant pas vu la campagne (moyenne 8,9/12, 74 %) (p<0,001). Les taux provinciaux de dépistage de la syphilis étaient de 8 764 et 9 749 au cours des 12 mois précédant et suivant la campagne; cependant, nous n'avons pas trouvé de tendance globale à la hausse des dépistages suite à la campagne (p=0,147). Parmi les participants Engage, 12,7 % ont déclaré avoir vu la campagne en ligne et nous avons trouvé une association entre l'exposition à la campagne et le dépistage récent de la syphilis (RCa=2,73; IC à 95 %=1,51, 4,93). CONCLUSION: Les gbHARSAH qui ont vu la campagne étaient plus susceptibles de déclarer avoir été testés pour la syphilis au cours des six derniers mois. Les participants aux cliniques ITS qui ont déclaré avoir vu la campagne avaient également une meilleure connaissance de la syphilis que ceux qui ne l'ont pas vue.

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.

Preventable mortality among sexual minority Canadians.

Background: Epidemiologic studies point to multiple health inequities among sexual minority people, but few studies have examined mortality. Some causes of death are more preventable than others, and access to prevention is theorized to follow patterns of access to social and material resources. The objective of this study is to compare estimates of preventable mortality between sexual minority (SM)-i.e., bisexual, lesbian, gay-and heterosexual adults in Canada. Methods: A population-based retrospective cohort with 442,260 (unweighted N) Canadian adults, ages 18-59 years, was drawn from the Canadian Community Health Survey/Canadian Mortality Database linked database (2003-2017). The Rutstein preventability rating index was used to classify cause-specific mortality (low/high). Longitudinal analyses were conducted using Cox proportional hazards models. Results: SM respondents had higher hazard of all-cause mortality (unadjusted hazard ratio [uHR] 1.28, 95% CI 1.06, 1.55). The uHR increased when the outcome was limited to highly-preventable causes of mortality (uHR 1.43, 95% CI 1.14, 1.80). The uHR further increased in sensitivity analyses using higher thresholds of the Rutstein index. SM respondents had higher hazard of cause-specific mortality for heart disease (uHR 1.53, 95% CI 1.03, 2.29), accidents (uHR 1.97, 95% CI 1.01, 3.86), HIV (uHR 75.69, 95% CI 18.77, 305.20), and suicide (uHR 2.22, 95% CI 0.93, 5.30) but not for cancer (uHR 0.86, 95% CI 0.60, 1.25). The adjusted HR (aHR) for highly-preventable mortality was not attenuated by adjustment for confounders (aHR 1.57, 95% CI 1.20, 2.05) but was reduced by adjustment for hypothesized mediators relating to access to social and material resources (marital status, children, income, education; aHR 1.11, 95% CI 0.78, 1.58). Conclusions: Preventable mortality was elevated for SM Canadians compared to heterosexuals. Early and broad access to sexual minority-affirming primary and preventive healthcare should be expanded.

British Columbia's Experience after Implementation of the Treponema pallidum Reverse Algorithm and PCR Detection, 2015 to 2020.

British Columbia (BC) implemented the syphilis reverse screening algorithm and Treponema pallidum PCR testing in 2014. We summarize the performance characteristics of the algorithm, together with PCR direct detection, and report on syphilis cases identified from 2015 to 2020. Prior to 2015, samples for syphilis diagnosis were first screened by rapid plasma reagin (RPR). As of 2015, sera were screened by the Siemens Advia Centaur syphilis assay (enzyme immunoassay [EIA]). Positive and equivocal samples were reflex tested by a T. pallidum passive particle agglutination assay (TPPA) and RPR. We used T. pallidum DNA PCR on clinical samples and restriction fragment length polymorphism analysis to identify azithromycin resistance mutations. Case/epidemiological data were obtained from the BC surveillance system. Of 1,631,519 samples screened by the EIA, 72,492 (4.4%) were positive and 187 (<0.1%) were equivocal. Of EIA-positive/equivocal samples, 10.6% were false positive, and false positivity was higher at lower EIA indices. The reverse algorithm detected 4,693 late latent syphilis cases that likely would have been missed by RPR screening. PCR had a very high sensitivity of 100% versus 52.9% and 52.4% for dark-field (DF) and immunofluorescence (IF) microscopy, respectively. The azithromycin resistance mutation A2058G was identified in 96% of PCR-positive samples, and A2059G was identified in 4%. Annually, there were 944 to 1,467 syphilis cases, with 62% in men who reported male sexual partners. The reverse algorithm had a low false-positive rate and very few equivocal screening results but did identify previously undiagnosed late latent syphilis cases. PCR was more sensitive than both DF and IF microscopy for direct diagnosis and enabled monitoring for azithromycin resistance. IMPORTANCE In this study, we summarize the performance characteristics of the algorithm, together with PCR direct detection and epidemiological analysis, and report on syphilis cases identified from 2015 to 2020. This allowed us to paint a complete picture of the outcome of the utilization of the reverse algorithm for diagnosing syphilis cases. The study clearly showed that the reverse algorithm had a low false-positive rate and very few equivocal screening results but did identify previously undiagnosed late latent syphilis cases. PCR was more sensitive than both DF and IF microscopy for direct diagnosis and enabled monitoring for azithromycin resistance.

Factors associated with intention to receive vaccines for bacterial sexually transmitted infections among young HPV-vaccinated Canadian women.

OBJECTIVE: The aim of this study was to explore the acceptability of bacterial STI vaccines among young HPV-vaccinated Canadian women to inform future vaccine program implementation. METHODS: A 20-item cross-sectional questionnaire was administered from June 2019 to June 2020 to HPV-vaccinated participants of the pan-Canadian QUEST cohort. Multivariable logistic regression models assessed interest in chlamydia, syphilis, and gonorrhea vaccines using a priori variables and factors significant in bivariate analysis. RESULTS: Of the 1092 respondents analyzed, 82% indicated interest in receiving one or more future STI vaccines. Respondents had a median age of 19.6 years (range 16.9-23.4), and 75% of respondents identified as white/European descent. In adjusted analyses, intent to engage in positive health behaviours was associated with vaccine interest for syphilis (OR = 5.76, 95% CI 4.03-8.27), chlamydia (OR = 5.27, 95% CI 3.66-7.63), and gonorrhea (OR = 5.96, 95% CI 4.15-8.60). Willingness to pay for an STI vaccine was also associated with vaccine interest for syphilis (OR = 2.02, 95% CI 1.29-3.19), chlamydia (OR = 2.41, 95% CI 1.50-3.90), and gonorrhea (OR = 2.29, 95% CI 1.44-3.63). Ever having sexual intercourse and identifying as LGBTQ were significantly associated with vaccine interest for all infections, while age and ever being immunosuppressed were not significant in any adjusted models. CONCLUSION: Findings indicate over 80% of participants in a cohort of young HPV-vaccinated Canadian women are interested in receiving future bacterial STI vaccines. Further exploration of STI vaccine acceptability among diverse populations is required to inform future bacterial STI vaccine program implementation.

RéSUMé: OBJECTIF: Cette étude visait à explorer l'acceptabilité des vaccins contre les ITS bactériennes chez les jeunes Canadiennes vaccinées contre le VPH pour éclairer la mise en œuvre de futurs programmes de vaccination. MéTHODE: Un questionnaire transversal de 20 questions a été administré entre juin 2019 et juin 2020 aux participantes de la cohorte QUEST pancanadienne ayant été vaccinées contre le VPH. Des modèles de régression logistique multivariée ont permis d'analyser l'intérêt pour les vaccins contre la chlamydia, la syphilis et la gonorrhée à l'aide de variables a priori et des facteurs significatifs dans l'analyse bivariée. RéSULTATS: Sur les 1 092 répondantes analysées, 82 % ont manifesté l'intérêt de recevoir un ou plusieurs futurs vaccins contre les ITS. L'âge médian des répondantes était de 19,6 ans (intervalle 16,9­23,4), et 75 % s'identifiaient comme étant blanches/d'ascendance européenne. Dans les analyses ajustées, l'intention de s'adonner à des comportements de santé positifs était associée à l'intérêt pour les vaccins contre la syphilis (RC = 5,76, IC de 95 % 4,03­8,27), la chlamydia (RC = 5,27, IC de 95 % 3,66­7,63) et la gonorrhée (RC = 5,96, IC de 95 % 4,15­8,60). La volonté de payer pour un vaccin contre les ITS était aussi associée à l'intérêt pour les vaccins contre la syphilis (RC = 2,02, IC de 95 % 1,29­3,19), la chlamydia (RC = 2,41, IC de 95 % 1,50­3,90) et la gonorrhée (RC = 2,29, IC de 95 % 1,44­3,63). Le fait d'avoir déjà eu des rapports sexuels et le fait de s'identifier comme une personne LGBTQ présentaient une corrélation significative avec l'intérêt pour les vaccins contre toutes les infections, mais l'âge et le fait d'avoir déjà subi un traitement immunodépresseur n'étaient des facteurs significatifs dans aucun des modèles ajustés. CONCLUSION: Selon nos constatations, plus de 80 % des participantes d'une cohorte de jeunes Canadiennes vaccinées contre les VPH sont intéressées à recevoir de futurs vaccins contre les ITS bactériennes. Une exploration plus poussée de l'acceptabilité des vaccins contre les ITS dans des populations à forte mixité est nécessaire pour éclairer la mise en œuvre de futurs programmes de vaccination contre les ITS bactériennes.

Increases in human papillomavirus vaccine coverage over 12 months among a community-recruited cohort of gay, bisexual, and other men who have sex with men in Canada.

BACKGROUND: Starting in 2015/16, most Canadian provinces introduced publicly-funded human papillomavirus (HPV) vaccination programs for gay, bisexual, and other men who have sex with men (GBM) aged ≤ 26 years. We estimated 12-month changes in HPV vaccine coverage among community-recruited GBM from 2017 to 2021 and identified baseline factors associated with vaccine initiation (≥1 dose) or series completion (3 doses) among participants who were unvaccinated or partially vaccinated at baseline. METHODS: We recruited sexually-active GBM aged ≥ 16 years in Montreal, Toronto, and Vancouver, Canada, from 02/2017 to 08/2019 and followed them over a median of 12 months (interquartile range = 12-13 months). We calculated the proportion who initiated vaccination (≥1 dose) or completed the series (3 doses) by 12-month follow-up. Analyses were stratified by city and age-eligibility for the publicly-funded programs at baseline (≤26 years or > 26 years). We used multivariable logistic regression to identify baseline factors associated with self-reported incident vaccine initiation or series completion. RESULTS: Among 165 unvaccinated participants aged ≤ 26 years at baseline, incident vaccine initiation (≥1 dose) during follow-up was 24.1% in Montreal, 33.3% in Toronto, and 38.9% in Vancouver. Among 1,059 unvaccinated participants aged > 26 years, incident vaccine initiation was 3.4%, 8.9%, and 10.9%, respectively. Higher education and trying to access pre-exposure prophylaxis for HIV were associated with incident vaccination among those aged ≤ 26 years, while younger age, residing in Vancouver (vs. Montreal), being diagnosed with anogenital warts, having both government and private extended medical insurance, and being vaccinated against influenza were associated with incident vaccination among those aged > 26 years. CONCLUSIONS: We observed substantial gains in HPV vaccine coverage among young GBM within 5 + years of targeted program implementation, but gaps remain, particularly among older men who are ineligible for publicly-funded programs. Findings suggest the need for expanded public funding or insurance coverage for HPV vaccines.

Characterizing female infectious syphilis cases in British Columbia to identify opportunities for optimization of care.

Introduction: The rate of infectious syphilis continues to increase among females in British Columbia (BC) and Canada, raising concerns of increased incidence of congenital syphilis. We characterized syphilis cases among females in BC to identify opportunities to prevent syphilis and optimize its care. Methods: All cases of infectious syphilis diagnosed in BC between March 13, 2018 and December 31, 2020 and reported as female gender were reviewed. Demographics, risk factors and concurrent conditions were collected from a provincial surveillance system. Subgroup analyses comparing cases with and without housing instability, substance use, mental illness and a recent sexually transmitted infection (STI) were conducted to understand differences between these subgroups. Statistical associations were calculated using chi-square or t-tests. Results: There were 226 reported cases of female infectious syphilis in BC during this period: 38 (16.8%) in 2018; 74 (32.7%) in 2019; and 114 (50.4%) in 2020. Mean age was 32 years (range 15-75 years). Of those who reported concurrent conditions, most cases had experiences with housing instability (71.1%), substance use (68.2%) and mental illness (83.9%), while 42.9% had a recent STI. Cases who reported housing instability or substance use were significantly more likely to have experiences with a recent STI, street involvement, transactional sex, mental illness and income assistance (all p<0.01). Conclusion: Our findings highlight the importance of fostering an enabling environment for syphilis care. Concurrent services to support individuals with syphilis as well as housing instability, substance use and mental illness, may help prevent syphilis and improve wellbeing.

A systematic review of the impacts of oral tetracycline class antibiotics on antimicrobial resistance in normal human flora.

OBJECTIVES: There is interest in doxycycline as prophylaxis against sexually transmitted infections (STIs), but concern about antimicrobial resistance (AMR). We conducted a systematic review (CRD42021273301) of the impact of oral tetracycline-class antibiotics on AMR in normal flora. METHODS: We searched MEDLINE, EMBASE, the Cochrane Library (1940-2021) and conference proceedings (2014-21) for randomized controlled trials in adults comparing daily oral tetracycline-class antibiotics to non-tetracycline controls. The primary outcome was AMR to tetracyclines; secondary outcomes included resistance to non-tetracyclines. Data were inappropriate for meta-analysis, so we analysed findings descriptively. RESULTS: Our search yielded 6265 abstracts of which 7 articles fulfilled inclusion criteria. Most were at moderate/high risk of bias, generally due to inadequate methodologic reporting. Studies used doxycycline, tetracycline, oxytetracycline or minocycline for 2-18 weeks. Most observed an increased burden of tetracycline resistance, including in subgingival (n = 3 studies), gastrointestinal (n = 2) and upper respiratory tract (n = 1) flora; one study of skin flora found no change in tetracycline-resistant Propionibacterium species after 18 weeks of oxytetracycline/minocycline. Four studies reassessed AMR at 2-50 weeks post-intervention and reported varying degrees of resistance. Three articles reported on the prevalence of non-tetracycline AMR after doxycycline prophylaxis, of which one found a transient increase among gastrointestinal Escherichia coli; the other two showed no difference from control. CONCLUSIONS: Although the effects are modest and transient, limited data from small prospective studies may suggest that oral tetracyclines for 2-18 weeks increase resistance in subgingival, gastrointestinal and upper respiratory tract flora. STI prophylaxis trials should include AMR in commensal bacteria as study outcomes.