Zishan Cui

HIV Community Viral Load and Factors Associated With Elevated Viremia Among a Community-Based Sample of Men Who Have Sex With Men in Vancouver, Canada.

Background:We developed estimates of community viral load (VL) and risk factors for unsuppressed VL from a cross-sectional study of men who have sex with men (MSM) in Vancouver, Canada. Methods:MSM were recruited from February 25, 2012 to February 28, 2014 using respondent-driven sampling (RDS). Participants completed a computer-assisted self-interview questionnaire and a nurse-administered point-of-care HIV test. For HIV-positive participants, we conducted VL and CD4 cell counts. We used RDS-weighted analysis to obtain population estimates of key variables and multivariable logistic regression to examine factors associated with having a VL of ≥200 copies per milliliter among HIV-positive participants. Results:We recruited 719 participants, of whom 119 (16.6%) were seeds. Our estimate of the population prevalence of HIV was 23.4% [95% confidence interval (CI): 15.8% to 31.0%] after RDS adjustments. We estimated that 18.6% (95% CI: 8.8% to 30.4%) of HIV-positive MSM in Vancouver had a VL of ≥200 copies per milliliter. Having an unsuppressed VL was associated with non-white ethnicity [adjusted odds ratio (AOR) = 4.34; 95% CI: 1.67 to 11.1], an annual income of <

Cohort Profile: HAART Observational Medical Evaluation and Research (HOMER) Cohort

15,000 CAD (AOR = 6.43; 95% CI: 2.08 to 19.9), using gamma-hydroxy butyrate in the previous 6 months (AOR = 4.85; 95% CI: 1.79 to 13.2), unprotected anal intercourse with a known HIV-negative or an unknown serostatus partner (AOR = 3.13; 95% CI: 1.10 to 8.90), and disclosing ones HIV serostatus ≥50% of the time (AOR = 7.04; 95% CI: 1.01 to 49.1). Conclusion:Despite a high prevalence of HIV, we estimated that a small proportion of HIV-positive MSM have undiagnosed HIV and unsuppressed VL. Our results highlight the importance of continued work to address health inequities using a framework based on social determinants of health.

Including Online-Recruited Seeds: A Respondent-Driven Sample of Men Who Have Sex With Men

Since 1986, antiretroviral therapy (ART) has been available free of charge to individuals living with HIV in British Columbia (BC), Canada, through the BC Centre of Excellence in HIV/AIDS (BC-CfE) Drug Treatment Program (DTP). The Highly Active Antiretroviral Therapy (HAART) Observational Medical Evaluation and Research (HOMER) cohort was established in 1996 to maintain a prospective record of clinical measurements and medication profiles of a subset of DTP participants initiating HAART in BC. This unique cohort provides a comprehensive data source to investigate mortality, prognostic factors and treatment response among people living with HIV in BC from the inception of HAART. Currently over 5000 individuals are enrolled in the HOMER cohort. Data captured include socio-demographic characteristics (e.g. sex, age, ethnicity, health authority), clinical variables (e.g. CD4 cell count, plasma HIV viral load, AIDS-defining illness, hepatitis C co-infection, mortality) and treatment variables (e.g. HAART regimens, date of treatment initiation, treatment interruptions, adherence data, resistance testing). Research findings from the HOMER cohort have featured in numerous high-impact peer-reviewed journals. The HOMER cohort collaborates with other HIV cohorts on both national and international scales to answer complex HIV-specific research questions, and welcomes input from external investigators regarding potential research proposals or future collaborations. For further information please contact the principal investigator, Dr Robert Hogg (robert_hogg@sfu.ca).

Gay and bisexual men’s awareness and knowledge of treatment as prevention: findings from the Momentum Health Study in Vancouver, Canada

Background Technology has changed the way men who have sex with men (MSM) seek sex and socialize, which may impact the implementation of respondent-driven sampling (RDS) among this population. Initial participants (also known as seeds) are a critical consideration in RDS because they begin the recruitment chains. However, little information is available on how the online-recruited seeds may effect RDS implementation. Objective The objectives of this study were to compare (1) online-recruited versus offline-recruited seeds and (2) subsequent recruitment chains of online-recruited versus offline-recruited seeds. Methods Between 2012 and 2014, we recruited MSM using RDS in Vancouver, Canada. RDS weights were used with logistic regression to address each objective. Results A total of 119 seeds were used, 85 of whom were online-recruited seeds, to recruit an additional 600 MSM. Compared with offline-recruited seeds, online-recruited seeds were less likely to be HIV-positive (OR 0.34, 95% CI 0.13-0.88), to have attended a gay community group (AOR 0.33, 95% CI 0.12-0.90), and to feel gay community involvement was “very important” (AOR 0.16, 95% CI 0.03-0.93). Online-recruited seeds were more likely to ask a sexual partner’s HIV status always versus <50% of the time (AOR 5.21, 95% CI 1.17-23.23), to have watched the Pride parade (AOR 6.30, 95% CI 1.69-23.45), and to have sought sex online (AOR 4.29, 95% CI 1.53-12-12.05). Further, compared with recruitment chains started by offline-recruited seeds, recruits from chains started by online-recruited seeds (283/600, 47.2%) were less likely to be HIV-positive (AOR 0.25, 95% CI 0.16-0.40), to report “versatile” versus “bottom” sexual position preference (AOR 0.56, 95% CI 0.35-0.88), and to be in a relationship lasting >1 year (AOR 1.65, 95% CI 1.06-2.56). Recruits of online seeds were more likely to be out as gay for longer (eg, 11-21 vs 1-4 years, AOR 2.22, 95% CI 1.27-3.88) and have fewer Facebook friends (eg, 201-500 vs >500, AOR 1.69, 95% CI 1.02-2.80). Conclusions Online-recruited seeds were more prevalent, recruited fewer participants, but were different from those recruited offline. This may therefore help create a more diverse overall sample. Our work has shown the value of geosocial networking apps for aiding RDS recruitment efforts, especially when faced with slow participation uptake by other means. Understanding the degree to which networks interact will be an important next step in confirming the efficacy of online RDS recruitment strategies.

An Event-Level Analysis of the Interpersonal Factors Associated With Condomless Anal Sex Among Gay, Bisexual, and Other Men Who Have Sex With Men (MSM) With Online-Met Partners

Awareness and knowledge of treatment as prevention (TasP) was assessed among HIV‐positive and HIV‐negative gay, bisexual and other men who have sex with men (GBMSM) in Vancouver, Canada.

Exploring the role of sex-seeking apps and websites in the social and sexual lives of gay, bisexual and other men who have sex with men: a cross-sectional study.

The interpersonal determinants of condomless anal sex (CAS) within online-initiated sexual relationships remain poorly understood. Therefore, respondent-driven sampling was used to recruit a prospective cohort of sexually active gay, bisexual, and other men who have sex with men (MSM), aged ≥ 16 years in Vancouver, Canada. Follow-up occurred every 6 months, up to seven visits; at each visit participants reported their last sexual encounter with their five most recent partners. Stratified by self-reported HIV status, individual-level, interpersonal, and situational covariates of event-level CAS with partners met online were modeled using generalized estimating equations (GEE). CAS was reported during 32.4% (n = 1,015/3,133) of HIV-negative/unknown mens events, and 62.1% (n = 576/928) of HIV-positive mens events. Social (i.e., collective identity, altruism, network size social embeddedness) and situational (i.e., number of encounters, location, comparative age, seroconcordance, substance use) factors were identified as important correlates of CAS. Implications include the need for HIV prevention addressing social contexts associated with CAS.

Substance use, sexual behaviour and prevention strategies of Vancouver gay and bisexual men who recently attended group sex events

Background The objective of this study was to explore the relationship between online sex-seeking, community/social attachment and sexual behaviour. METHODS Respondent-driven sampling was used to recruit 774 sexually active gay and bisexual men in Vancouver, Canada, aged ≥16 years. Multivariable logistic regression compared men who had used online sex-seeking apps/websites in the past 6 months (n=586) with those who did not (n=188). RESULTS Multivariable results showed that online sex seekers were more likely to be younger [adjusted odds ratio (aOR)=0.95, 95% CI: (0.93-0.96)], college educated [aOR=1.60, 95% CI: (1.07, 2.40)], have more Facebook friends [aOR=1.07, 95% CI: (1.01, 1.13)], spend more social time with other gay men [aOR=1.99, 95% CI: (1.33-2.97)], and were less likely to identify emotionally with the gay community [aOR=0.93, 95% CI: (0.86-1.00)]. Further, they had displayed high sensation-seeking behaviour [aOR=1.08, 95% CI: (1.03-1.13)], were more likely to engage in serodiscordant/unknown condomless anal sex [aOR=2.34, 95% CI: (1.50-3.66)], use strategic positioning [aOR=1.72, 95% CI: (1.08-2.74)], ask their partners HIV-status prior to sex [aOR=2.06, 95% CI: (1.27-3.37)], and have ever been tested for HIV [aOR=4.11, 95% CI: (2.04-8.29)]. CONCLUSION These findings highlight the online and offline social behaviour exhibited by gay and bisexual men, pressing the need for pro-social interventions to promote safe-sex norms online. We conclude that both Internet and community-based prevention will help reach app/web users.

Estimating the Size of the MSM Population in Metro Vancouver, Canada, Using Multiple Methods and Diverse Data Sources

Abstract Group sex events are an epidemiologically important part of some gay and bisexual men’s sexual culture in Canada. Associated with condomless anal intercourse and polysubstance use, such events have been cited as disproportionally contributing to HIV infection rates. We analysed questionnaire data from the Momentum Health Study in Vancouver, Canada, to understand substance use, sexual behaviour, psychosocial variables (Sexual Sensation Seeking, Sexual Escape Motivation, Treatment Optimism) and HIV prevention strategies (sero-sorting, strategic positioning, avoiding anal sex, disclosure, treatment as prevention) of men attending such events, which were defined as group (n ≥ 4 partners) sex parties, blackout events and darkrooms. Analysis by multivariable logistic regression compared men attending group sex events within the past six months (n = 180) with non-attendees (n = 539). Results showed that attendees reported: (1) significantly higher use of sex drugs and alcohol consumption, (2) higher scores on the Sexual Sensation Scale, more anal sex partners, greater odds of any condomless anal sex with sero-discordant partners and greater odds of reporting fisting and sex toy use and (3) different prevention practices that varied by HIV-serostatus. Findings are interpreted in light of the importance of pleasure, sociality and HIV/STI prevention strategies associated with group sex events. Findings contribute to the development of appropriate education and intervention for attendees.

Prevalence, type, and correlates of trauma exposure among adolescent men and women in Soweto, South Africa: implications for HIV prevention.

Men who have sex with men (MSM) are disproportionately affected by HIV globally, regionally in Canada, and locally in Vancouver. Lack of reliable population size estimates of MSM impedes effective implementation of health care services and limits our understanding of the HIV epidemic. We estimated the population size of MSM residing in Metro Vancouver drawing on four data sources: the Canadian Community Health Survey (CCHS), a cross-sectional bio-behavioural MSM survey, HIV testing services data from sexually transmitted infection (STI) clinics serving MSM, and online social networking site Facebook. Estimates were calculated using (1) direct estimates from the CCHS, (2) “Wisdom of the Crowds” (WOTC), and (3) the multiplier method using data from a bio-behavioural MSM survey, clinic-based HIV testing, and online social media network site Facebook. Data sources requiring greater public disclosure of sexual orientation resulted in our mid-range population estimates (Facebook 23,760, CCHS 30,605). The WOTC method produced the lowest estimate, 10,000. The multiplier method using STI clinic HIV testing data produced the largest estimate, 41,777. The median of all estimates was 27,183, representing 2.9% of the Metro Vancouver census male adult population, with an interquartile range of 1.1–4.5%. Using multiple data sources, our estimates of the MSM population in Metro Vancouver are similar to population prevalence estimates based on population data from other industrialized nations. These findings will support understanding of the HIV burden among MSM and corresponding public health and health services planning for this key population.

Modelling clinical progression and health care utilization of HIV-positive patients in British Columbia prior to death.

BackgroundYouth trauma exposure is associated with syndemic HIV risk. We measured lifetime prevalence, type, and correlates of trauma experience by gender among adolescents living in the HIV hyper-endemic setting of Soweto, South Africa.MethodsUsing data from the Botsha Bophelo Adolescent Health Survey (BBAHS), prevalence of “ever” experiencing a traumatic event among adolescents (aged 14–19) was assessed using a modified Traumatic Event Screening Inventory-Child (TESI-C) scale (19 items, study alpha = 0.63). We assessed self-reported number of potentially traumatic events (PTEs) experienced overall and by gender. Gender-stratified multivariable logistic regression models assessed independent correlates of ‘high PTE score’ (≥7 PTEs).ResultsOverall, 767/830 (92%) participants were included (58% adolescent women). Nearly all (99.7%) reported experiencing at least one PTE. Median PTE was 7 [Q1,Q3: 5-9], with no gender differences (p = 0.19). Adolescent men reported more violent PTEs (e.g., “seen an act of violence in the community”) whereas women reported more non-violent HIV/AIDS-related PTEs (e.g., “family member or someone close died of HIV/AIDS”). High PTE score was independently associated with high food insecurity among adolescent men and women (aOR = 2.63, 95%CI = 1.36-5.09; aOR = 2.57, 95%CI = 1.55-4.26, respectively). For men, high PTE score was also associated with older age (aOR = 1.40/year, 95%CI = 1.21-1.63); and recently moving to Soweto (aOR = 2.78, 95%CI = 1.14-6.76). Among women, high PTE score was associated with depression using the CES-D scale (aOR = 2.00, 95%CI = 1.31-3.03,) and inconsistent condom use vs. no sexual experience (aOR = 2.69, 95%CI = 1.66-4.37).ConclusionNearly all adolescents in this study experienced trauma, with gendered differences in PTE types and correlates, but not prevalence. Exposure to PTEs were distributed along social and gendered axes. Among adolescent women, associations with depression and inconsistent condom use suggest pathways for HIV risk. HIV prevention interventions targeting adolescents must address the syndemics of trauma and HIV through the scale-up of gender-transformative, youth-centred, trauma-informed integrated HIV and mental health services.