Antiretroviral treatment initiation among HIV-positive participants in the Bangkok men who have sex with men cohort study, 2006-2016.

INTRODUCTION: Data on HIV antiretroviral therapy (ART) initiation among key-affected populations will support reaching the UNAIDS goal to end AIDS by 2030. METHODS: We assessed ART initiation among HIV-positive participants of the Bangkok Men Who Have Sex with Men (MSM) Cohort Study, which enrolled sexually experienced MSM aged ≥ 18 years and included visits every four months for a period of 3-5 years, from 2006-2016. At each visit, participants had HIV testing and completed computer-assisted self-interviewing on demographics and HIV risk behaviors. If they acquired HIV infection during the study, they received active referral for HIV treatment, continued in the cohort, and were asked about ART initiation. We used logistic regression to determine factors associated with ART initiation. RESULTS: Overall, 632 (36.2%) participants were diagnosed with HIV infection; 463 (73%) had a follow-up visit reporting information about ART, of those 346 (74%) reported ART initiation, with 323 (93%) on ART initiating ART through their registered national health benefit program. Only 70 (11%) were eligible for ART at time of diagnosis, and 52 (74%) initiated ART, on average, within six months of diagnosis. Multivariable analysis evaluating factors associated with ART initiation demonstrated that low CD4 cell count at time of diagnosis was the only independent factor associated with ART initiation. CONCLUSIONS: Most HIV-positive participants in the cohort reported ART initiation through the national health benefit program but limited data suggests there could be improvements in length of time to initiation of ART. Efforts should focus on ART start in MSM and transgender women soon after HIV diagnosis.

Spatial characteristics of men who have sex with men and transgender women attending HIV voluntary counselling and testing in Bangkok, Thailand, 2005-2015.

Spatiotemporal analyses can support Human Immuno-deficiency Virus (HIV) prevention programmes by identifying locations of at-risk populations in space and time, and their proximity to HIV testing and prevention services. We assessed residential proximity to HIV testing venues for Men who have Sex with Men (MSM) and Transgender Women (TGW) attending Voluntary Counselling and Testing (VCT) at a large urban MSM clinic in Bangkok, Thailand in the period 2005-2015. We mapped clientprovided spatial data and HIV testing venues, calculating distance from residence to venues for VCT clients between i) September 2005-December 2009; ii) January 2010-September 2013; and iii) October 2013-May 2015. We assessed spatial characteristics across times, evaluating autocorrelation of HIV prevalence and visit density using Moran's I. Among 8,758 first-time VCT clients reporting geographic information from 2005-2015 (by period: 2737, 3917, 2104), 1329 (15.2%) lived in postal codes ≤5 km from the clinic. Over time, the proportion living in areas covered by Bangkok postal codes ≤2 km from any MSM HIV testing venue increased from 12.6% to 41.0% (p<0.01). The proportion living ≤5 km from the clinic decreased from 16.6% to 13.0% (p<0.01). HIV prevalence and clinic visit density demonstrated statistically significant non-random spatial patterning. Significant non-random patterning of prevalent infection and client visits highlighted Bangkok's urban HIV epidemic, clinic proximity to clients, and geographic reach. Clients lived closer to testing venues, yet farther from the urban MSM clinic, over time. Spatiotemporal characteristics of VCT clients can help assess service accessibility and guide targeted prevention planning.

Estimating the impact of HIV combination prevention in men who have sex with men, the Bangkok MSM Cohort Study, Thailand.

In Thailand, pre-exposure prophylaxis (PrEP) is recommended for human immunodeficiency virus (HIV) prevention among at-risk men who have sex with men (MSM). We modeled the impact of PrEP and condom use as independent and combined interventions on the estimated number of HIV infections among a hypothetical population of 10,000 MSM in Bangkok, Thailand. Our model demonstrated a 92% (95% confidence interval 89.7, 94.2) reduction in HIV infections among Thai MSM who took daily PrEP and self-reported using condoms correctly and consistently (100% condom use). Increased use of PrEP and condoms likely would have a substantial impact on the HIV epidemic in Thailand.

Repeat HIV testing among HIV-uninfected men who have sex with men attending Silom Community Clinic, Bangkok, 2011 - 2014.

Since 2010, the Thailand Ministry of Public Health has recommended that men who have sex with men (MSM) have an HIV test at least two times a year. We calculated the proportion of, and factors associated with, testing adherence among the HIV-uninfected MSM clients attending Silom Community Clinic @TropMed. We defined testing adherence as repeating at least one HIV test within six months of an initial HIV-negative test, and used log-binomial regression to test for associated factors. We included 1927 clients during 2011­2014; 362 (19%) were adherent with an increased trend (p < 0.01), from 16% to 24%. Clients aged 18­24 years and those having a history of HIV testing were more likely to adhere (aRR: 1.3, 95% CI: 1.1­1.6; and aRR: 1.3, 95% CI: 1.0­1.5, respectively). One-fifth adhered to the recommendation; older clients or naïve testees were less likely to adhere. We need to impress on clients the importance of repeat HIV testing.

The finding of casual sex partners on the internet, methamphetamine use for sexual pleasure, and incidence of HIV infection among men who have sex with men in Bangkok, Thailand: an observational cohort study.

BACKGROUND: The finding of casual sex partners on the internet and methamphetamine use have been described as risk factors for HIV infection in men who have sex with men (MSM). However, the interplay between these factors has not been studied prospectively in one design. This study aims to determine the associations between finding casual sex partners on the internet and incident methamphetamine use and HIV infection. METHODS: In this observational cohort study of Thai MSM, we recruited Bangkok residents aged 18 years or older with a history of penetrative male-to-male sex in the past 6 months. Baseline and follow-up visits were done at a dedicated study clinic in central Bangkok. Men were tested for HIV infection at every study visit and for sexually transmitted infections at baseline. Baseline demographics and HIV risk behaviour information were collected at every visit by audio computer-assisted self-interview. We used a descriptive model using bivariate odds ratios to elucidate the order of risk factors in the causal pathway to HIV incidence and methamphetamine use. We used Cox proportional hazard regression analysis to evaluate covariates for incident methamphetamine use and HIV infection. FINDINGS: From April 6, 2006, to Dec 31, 2010, 1977 men were screened and 1764 were found eligible. 1744 men were enrolled, of whom 1372 tested negative for HIV and were followed up until March 20, 2012. Per 100 person-years of follow-up, incidence of methamphetamine use was 3·8 (128 events in 3371 person-years) and incidence of HIV infection was 6·0 (212 events in 3554 person-years). In our descriptive model, methamphetamine use, anal sex, and various other behaviours cluster together but their effect on HIV incidence was mediated by the occurrence of ulcerative sexually transmitted infections. Dual risk factors for both incident methamphetamine use and HIV infection were younger age and finding casual sex partners on the internet. Having ever received money for sex was predictive for incident methamphetamine use; living alone or with a housemate, recent anal sex, and ulcerative sexually transmitted infections at baseline were predictive for incident HIV infection. INTERPRETATION: In MSM in Bangkok, casual sex partner recruitment on the internet, methamphetamine use, and sexually transmitted infections have important roles in sustaining the HIV epidemic. Virtual HIV prevention education, drug use harm reduction, and biomedical HIV prevention methods, such as pre-exposure prophylaxis, could help to reduce or revert the HIV epidemic among MSM in Bangkok. FUNDING: US Centers for Disease Control and Prevention and the Johns Hopkins Fogarty AIDS International Training and Research Program.

Young Men Who Have Sex with Men at High Risk for HIV, Bangkok MSM Cohort Study, Thailand 2006-2014.

High HIV incidence has been reported in young men who have sex with men (YMSM) in North America and Western Europe, but there are limited data from Southeast Asia suggesting MSM may be the driver of the HIV epidemic in this region. We described HIV incidence and risk factors among 494 YMSM enrolled in a cohort study in Bangkok, Thailand. The HIV incidence was 7.4 per 100 person-years. In multivariable analysis, reporting use of an erectile dysfunction drug in combination with club drugs, having receptive or both insertive and receptive anal intercourse with men, having hepatitis A infection, having rectal Chlamydia trachomatis, having hepatitis B infection prior to HIV seroconversion, and reporting not always using condoms with male steady partners were significantly associated with HIV incidence in YMSM. Reduction in new HIV infections in YMSM are critical to reach targets set by Thailand and the region.

Subtypes and Risk Behaviors Among Incident HIV Cases in the Bangkok Men Who Have Sex with Men Cohort Study, Thailand, 2006-2014.

HIV-1 incidence and prevalence remain high among men who have sex with men (MSM), and transgender women (TGW), in Thailand. To examine the link between epidemiologic factors and HIV-1 subtype transmission among Thai MSM, we compared covariates of infection with HIV CRF01_AE and other HIV strains among participants in the Bangkok MSM Cohort Study (BMCS). The BMCS was an observational cohort study of Thai MSM and TGW with up to 60 months of follow-up at 4 monthly intervals. Participants underwent HIV/sexually transmitted infections testing and provided behavioral data at each visit. Infecting viral strain was characterized by gene sequencing and/or multiregion hybridization assay. We correlated behavioral/clinical variables with infecting strain using Cox proportional hazards. Among a total of 1372 HIV seronegative enrolled participants with 4,192 person-years of follow-up, we identified 215 seroconverters between April 2006 and December 2014, with 177 infected with CRF01_AE and 38 with non-CRF01_AE subtype. Age 18-21 years (adjusted hazard ratio [AHR] 2.2, 95% confidence interval [CI]: 1.4-3.5), age 22-29 (AHR 1.6, 95% CI: 1.1-2.3), living alone (AHR 1.5, 95% CI: 1.1-2.1), drug use (AHR 2.2, 95% CI: 1.4-3.5), intermittent condom use (AHR 1.7, 95% CI: 1.3-2.3), any receptive anal intercourse (AHR 1.7, 95% CI: 1.2-2.4), group sex (AHR 1.5, 95% CI: 1.1-2.2), anti-herpes simplex virus type 1 (AHR 1.5, 95% CI: 1.1-2.1), and Treponema pallidum antibody positivity (AHR 2.5, 95% CI: 1.4-4.4) were associated with CRF01_AE infection. Age 18-21 years (AHR 5.1, 95% CI: 1.6-16.5), age 22-29 (AHR 3.6, 95% CI: 1.3-10.4), drug use (AHR 3.1, 95% CI: 1.3-7.5), group sex (AHR 2.4, 95% CI: 1.1-5.0), and hepatitis B virus surface antigen (AHR 3.6, 95% CI: 1.3-10.2) were associated with non-CRF01_AE infection. We observed several significant biological and behavioral correlates of infection with CRF01_AE and other HIV strains among Thai MSM. Divergence in correlates by strain may indicate differences in HIV transmission epidemiology between CRF01_AE and other strains. These differences could reflect founder effects, transmission within networks distinguished by specific risk factors, and possibly biological differences between HIV strains.

Incidence of and temporal relationships between HIV, herpes simplex II virus, and syphilis among men who have sex with men in Bangkok, Thailand: an observational cohort.

BACKGROUND: High HIV incidence has been detected among men who have sex with men (MSM) in Thailand, but the relationship and timing of HIV, herpes simplex virus 2 (HSV-2), and syphilis is unknown. This analysis measures incidence, temporal relationships, and risk factors for HIV, HSV-2, and syphilis among at-risk MSM in the Bangkok MSM Cohort Study. METHODS: Between April 2006 and December 2010, 960 men negative for HIV, HSV-2, and syphilis at entry enrolled and contributed 12-60 months of follow-up data. Behavioral questionnaires were administered at each visit; testing for HIV antibody was performed at each visit, while testing for syphilis and HSV-2 were performed at 12 month intervals. We calculated HIV, HSV-2, and syphilis incidence, assessed risk factors with complementary log-log regression, and among co-infected men, measured temporal relationships between infections with Kaplan-Meier survival analysis and paired t-test. RESULTS: The total number of infections and incidence density for HIV, HSV-2, and syphilis were 159 infections and 4.7 cases/100 PY (95 % Confidence Interval (CI): 4.0-5.4), 128 infections and 4.5/100 PY (95 % CI: 3.9-5.5), and 65 infections and 1.9/100 PY (95 % CI: 1.5-2.5), respectively. Among men acquiring >1 infection during the cohort period, mean time to HIV and HSV-2 infection was similar (2.5 vs. 2.9 years; p = 0.24), while syphilis occurred significantly later following HIV (4.0 vs. 2.8 years, p < 0.01) or HSV-2 (3.8 vs. 2.8 years, p = 0.04) infection. The strongest independent predictor of any single infection in adjusted analysis was acquisition of another infection; risk of syphilis (Adjusted Hazards Ratio (AHR) = 3.49, 95 % CI: 1.89-6.42) or HIV (AHR = 2.26, 95 % CI: 1.47-3.48) acquisition during the cohort was significantly higher among men with incident HSV-2 infection. No single independent behavioral factor was common to HIV, HSV-2, and syphilis acquisition. CONCLUSION: HIV and HSV-2 incidence was high among this Thai MSM cohort. However, acquisition of HIV and co-infection with either HSV-2 or syphilis was low during the time frame men were in the cohort. Evaluation of behavioral risk factors for these infections suggests different risks and possible different networks.

Loss to follow-up and bias assessment among a cohort of Thai men who have sex with men in Bangkok, Thailand.

Minimising loss to follow-up is essential to obtain unbiased results. This study aimed to assess factors associated with loss to follow-up and effects on biasing exposure-outcome associations in a cohort of men who have sex with men in Bangkok. We enrolled sexually-active Thai men who have sex with men, at least 18 years old, in a study with four-monthly follow-up visits. At each visit, men answered HIV risk behaviour questions using audio computer-assisted self-interview. Logistic regression was used to evaluate factors associated with loss to follow-up and bias between exposures and prevalent HIV infection were estimated using adjusted relative odds ratios. From 2006 to 2010, we enrolled 1744 men who have sex with men; as of April, 2014, 1256 (72%) had completed at least the month-36 visit; loss to follow-up was 9.6%. Factors independently associated with loss to follow-up were age (18-21 years), education (primary level or less, secondary or vocational education), living outside Bangkok and vicinity, sexual orientation (bisexual, heterosexual), previous HIV testing, HIV infection, and behaviour in the past 4 months (recreational drug use, reporting group sex). An effect of loss to follow-up on factors of prevalent HIV infection was found by sexual orientation (transgender) and unprotected anal intercourse (receptive/insertive). These findings highlight the need to strengthen post-HIV test counselling. Directed counselling for HIV care should be given to young men who have sex with men and recreational drug users.

Temporal trends in HIV-1 incidence and risk behaviours in men who have sex with men in Bangkok, Thailand, 2006-13: an observational study.

BACKGROUND: HIV-1 incidence in men who have sex with men (MSM) is often difficult to estimate. We therefore assessed temporal trends in HIV-1 incidence and behavioural risk factors in MSM in Bangkok, Thailand, from 2006 to 2013. METHODS: In this observational study, we used data for clients attending the Silom Community Clinic for voluntary counselling and testing (VCT) services and from the Bangkok MSM Cohort Study (BMCS) to investigate trends in HIV incidence per 100 person-years per quarter in both cohorts. During VCT, basic demographic data were gathered at registration. However, no behavioural risk data were gathered. In the BMCS, we gathered demographic and behavioural data at baseline and at regular study visits using audio computer-assisted self-interviewing. Questions were included about potential risk factors such as drug use, sexual practices, and how often condoms were used. We also analysed behavioural risk factors in the BMCS cohort, using a restricted cubic spline function for time. FINDINGS: From 2006 to 2013, 8176 MSM came for VCT; 1999 (24%) clients were initially seronegative and returned for another test. 235 (12%) individuals seroconverted. The overall HIV-1 incidence was 5.5 per 100 person-years (95% CI 4.8-6.3), with an increasing trend (adjusted p=0.02). In the BMCS, 1372 people were seronegative at baseline; 1259 (92%) had more than one follow-up test and 238 (17%) seroconverted. The overall HIV-1 incidence was 5.3 per 100 person-years (95% CI 4.7-6.1), with an increase and then a decline (inverted U-shaped curve, p=0.0001). Individuals aged 21 years and younger were at significantly higher risk of HIV infection than were those aged 30 years and older in the in the VCT (rate ratio 2.29, 95% CI 1.88-2.78, p<0.0001) and BMCS cohorts (1.99, 1.50-2.65, p<0.0001). Overall, drug use (p=0.03), drug use to enhance sex (p=0.0006), use of drugs for erectile dysfunction (p<0.0001), and 100% condom use (p<0.0001) increased over time, whereas the proportion of individuals reporting receptive anal intercourse decreased (p=0.004). INTERPRETATION: With a sustained high HIV-1 incidence and increasing drug use in MSM in Bangkok, we urgently need innovative and acceptable HIV prevention interventions, especially for young MSM. FUNDING: US Centers for Disease Control and Prevention.