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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.

Background The Greater Toronto Area (GTA) is home to 39% of Canada’s population living with HIV. To identify gaps in access and engagement in care and treatment, we assessed the care cascade of women living with HIV (WLWH) in the GTA versus the rest of Ontario and Canada (in this case: Quebec and British Columbia).Methods We analyzed 2013–2015 self-reported baseline data from the Canadian HIV Women’s Sexual and Reproductive Health Cohort Study for six care cascade stages: linked to care, retained in care, initiated antiretroviral therapy (ART), currently on ART, ART adherence (≥90%), and undetectable (<50 copies/mL). Multivariable logistic regression was used to reveal associations with being undetectable.Results Comparing the GTA to the rest of Ontario and Canada, respectively: 96%, 98%, 100% were linked to care; 92%, 94%, 98% retained in care; 72%, 89%, 96% initiated ART; 67%, 81%, 90% were currently using ART; 53%, 66%, 77% were adherent; 59%, 69%, 81% were undetectable. Factors associated with viral suppression in the multivariable model included: living outside of the GTA (Ontario: aOR = 1.72, 95% CI: 1.09–2.72; Canada: aOR = 2.42, 95% CI: 1.62–3.62), non-Canadian citizenship (landed immigrant/permanent resident: aOR = 3.23, 95% CI: 1.66–6.26; refugee/protected person/other status: aOR = 4.77, 95% CI: 1.96–11.64), completed high school (aOR = 1.77, 95% CI: 1.15–2.73), stable housing (aOR = 2.13, 95% CI: 1.33–3.39), income of ≥$20,000 (aOR = 1.52, 95% CI: 1.00–2.31), HIV diagnosis <6 years (6–14 years: aOR = 1.75, 95% CI: 1.16–2.63; >14 years: aOR = 1.87, 95% CI: 1.19–2.96), and higher resilience (aOR = 1.02, 95% CI: 1.00–1.04).Conclusion WLWH living in the GTA had lower rates of viral suppression compared to the rest of Ontario and Canada even after adjustment of age, ethnicity, and HIV diagnosis duration. High-impact programming for WLWH in the GTA to improve HIV outcomes are greatly needed.

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Background The real-world effectiveness of pre-exposure prophylaxis (PrEP) may be influenced by circulating HIV strains resistant to either tenofovir or emtricitabine. Yet, few studies have examined rates of resistance to these drugs in clinical settings.Methods We conducted a retrospective cohort study of antiretroviral-naive participants in the Canadian Observational Cohort collaboration who initiated antiretroviral therapy between 2006 and 2014. In separate analyses, we determined the prevalence of pretherapy resistance and cumulative incidence of follow-up resistance to tenofovir and emtricitabine. We used multivariable proportional hazards models to examine associations between baseline variables and the development of resistance.Results We studied 6,622 antiretroviral-naive participants initiating therapy, of whom 5,428 (82.0%) had a baseline resistance test. Baseline resistance to tenofovir and emtricitabine was observed in 83 (1.5%) and 21 (0.4%) patients, respectively. Among patients without baseline resistance, the cumulative incidence of resistance to tenofovir and emtricitabine 5 years following treatment initiation was 0.0070 (95% CI 0.0046, 0.0095) and 0.033 (95% CI 0.028, 0.038), respectively. Following multivariable analysis, a baseline viral load =100,000 copies/ml was associated with emergence of tenofovir (hazard ratio [HR] 2.88; 95% CI 1.35, 6.15) and emtricitabine (HR 2.27; 95% CI 1.64, 3.15) resistance. Initiating an integrase inhibitor-based regimen and CD4+T-cell count below 200 cells/mm3were also associated with resistance to each drug.Conclusions We observed a low prevalence of baseline resistance and a low incidence of emergence of resistance to tenofovir and emtricitabine among antiretroviral-naive patients in routine clinical care.

Background This study compared time to virological suppression and rebound between Indigenous and non-Indigenous individuals living with HIV in Canada initiating combination antiretroviral therapy (cART).Methods Data were from the Canadian Observational Cohort collaboration; eight studies of treatment-naive persons with HIV initiating cART after 1/1/2000. Fine and Gray models were used to estimate the effect of ethnicity on time to virological suppression (two consecutive viral loads [VLs] <50 copies/ml at least 3 months apart) after adjusting for the competing risk of death and time until virological rebound (two consecutive VLs >200 copies/ml at least 3 months apart) following suppression.Results Among 7,080 participants were 497 Indigenous persons of whom 413 (83%) were from British Columbia. The cumulative incidence of suppression 1 year after cART initiation was 54% for Indigenous persons, 77% for Caucasian and 80% for African, Caribbean or Black (ACB) persons. The cumulative incidence of rebound 1 year after suppression was 13% for Indigenous persons, 6% for Caucasian and 7% for ACB persons. Indigenous persons were less likely to achieve suppression than Caucasian participants (aHR=0.58, 95% CI 0.50, 0.68), but not more likely to experience rebound (aHR=1.03, 95% CI 0.84, 1.27) after adjusting for age, gender, injection drug use, men having sex with men status, province of residence, baseline VL and CD4+T-cell count, antiretroviral class and year of cART initiation.Conclusions Lower suppression rates among Indigenous persons suggest a need for targeted interventions to improve HIV health outcomes during the first year of treatment when suppression is usually achieved.

OBJECTIVE:Compare all-cause mortality between Indigenous participants and participants of other ethnicities living with HIV initiating combination antiretroviral therapy (cART) in an interprovincial multi-site cohort.

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.

Background The increased risk for cardiovascular disease (CVD) in HIV is well established. Despite high prevalence of viral hepatitis coinfection with HIV, there are few studies on the risk of CVD amongst antiretroviral therapy (ART)-treated coinfected patients.Methods Ontario HIV Treatment Network Cohort Study participants who initiated ART without prior CVD events were analysed. HBV and HCV coinfection were identified by serology and RNA test results. CVD was defined as any of: coronary artery disease including atherosclerosis, chronic ischaemic heart disease and arteriosclerotic vascular disease; myocardial infarction; congestive heart failure; cerebrovascular accident or stroke; coronary bypass; angioplasty; and sudden cardiac death. The impact of HBV and HCV coinfection on time to CVD was assessed using multivariable competing risk models accounting for left truncation between ART initiation and study enrolment.Results A total of 3,416 HIV-monoinfected, 432 HIV-HBV- and 736 HIV–HCV-coinfected individuals were followed for a median (IQR) of 2.32 years (1.36–8.02). Over the study period, 167 CVD events and 613 deaths were documented. After adjustment for age, gender, race, year initiating ART, weight and smoking status, HBV was not associated with time to CVD onset (aHR=1.05, 95% CI [0.63, 1.74]; P=0.86). There was an elevated risk of CVD for HCV-coinfected individuals, which approached statistical significance (aHR=1.44, 95% CI [0.97, 2.13]; P=0.07).Conclusions Our results are consistent with a moderate increase of CVD among individuals with HIV–HCV coinfection relative to those with HIV infection alone, lending support to consideration of initiation of HCV antiviral treatment.

We investigated the probability of transitioning in or out of the CD3T-cell homeostatic range during antiretroviral therapy, and we assessed the clinical impact of lost T-cell homeostasis (TCH) on AIDS-defining illnesses (ADIs) or death.

No studies have examined human papillomavirus (HPV) infections among couples early in their sexual relationships when transmission is most likely. Our objective was to describe the distribution of HPV infections among recently formed couples, using the partnership as the unit of analysis.

IntroductionIncidence of syphilis, chlamydia and gonorrhoea continue to rise among HIV-positive men who have sex with men (MSM) in Ontario. We previously observed an elevated risk of sexually transmitted infections (STI) among recreational drug users. Our aim was to determine the effect of a new STI diagnosis and recreational drug use on virologic failure (VF) among MSM successfully treated with antiretroviral therapy (ART). Our hypothesis is that any association between STIs and VF would be confounded by drug use.MethodsThe OHTN Cohort Study follows people receiving HIV care in Ontario. STI results and viral load (VL) data were retrieved via linkage with the provincial laboratory. We restricted analyses to 2610 MSM who completed>=1 annual questionnaire in 2008–2014 and had two consecutive VL<50 within a six-month period on ART. VF was defined as a single VL>=1000 or two consecutive VLs>=200. Periods of STI exposure were set around the diagnosis dates for each STI. We modelled STI diagnosis exposures and drug use as time-varying covariates on risk of VF using Cox regression adjusting for age, region and income as confounders. Our model allowed for repeat STI exposures and repeated VF events using the marginal means/rates model.ResultsThere were 472 VFs with a 24 month cumulative incidence of 12.1% (95%CI 11.1, 13.1). VFs at time of a new chlamydia or gonorrhoea infection were close to nil. We did not observe an increased risk of VF at the time of a new syphilis infection (HR=1.2 95% CI 0.8, 2.0; aHR=1.1 95% CI 0.7, 1.7). Risk was higher among drug users (non-injection aHR=1.4 95% CI 1.1, 1.8; injection aHR=1.8 95% CI 1.1, 2.6). There was no significant interaction but some evidence of positive confounding between syphilis and VF by drug use.ConclusionRegardless of drug use, we did not find an association between a new STI diagnosis and increased risk of VF among men on suppressive ART. Our data are limited by possible misclassification of STI exposures, because not all men were tested, and among those diagnosed, exact dates of acquisition were unknown.

IntroductionA complex, persistent syphilis epidemic has affected gay, bisexual and other men who have sex with men (gbMSM) in major urban centres in North America for over a decade. Our objective was to explore the sexual travels, networks, and knowledge of gbMSM in Toronto.MethodsWe conducted in-depth interviews between June and July 2016 with 31 gbMSM who were ≥18 years, actively seeking sexual partners, and living, working or socialising in downtown Toronto. We asked participants to map their egocentric sexual network, share their sexual partner-seeking strategies and knowledge of STIs. We analysed travel patterns between participants and their sexual partners, including in relation to the core area of elevated syphilis rates, and used interview transcripts to interpret and explore the context from which observed patterns emerged.ResultsFour geosexual archetypes dominated the egocentric sexual network maps, namely, hosters, two types of travellers: house-callers and rovers, and geoflexibles. These archetypes were observed in both core and noncore areas. Hosters usually or always hosted sex at their residence, creating a centralised sex phenomenon. Travellers rarely or never had sex at their residence. House-callers usually or always had sex at the residence of their sex partners; rovers also had sex at venues and other public spaces. Travellers created a dispersed sex phenomenon and bridging core, peripheral, and distant areas. Geoflexibles had sex anywhere (i.e.,home, venues, partner residences, public spaces). Participants practiced 1–2 online or in-person partner seeking strategies with little regard for syphilis because of overwhelming concern for HIV, lack of awareness of the syphilis epidemic, and treatability of the syphilis.ConclusionGeo-sexual patterns and travel between sexual partners suggest specific archetypes exist comprising the larger gbMSM sociocentric sexual network. Future research should better define and characterise these archetypes and explore how each may impact STI transmission and intervention.