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.

This analysis measures prevalence and correlates of consistent lubricant use among a cohort of Thai men who have sex with men (MSM). Lubricant use was queried at the 12 month follow-up visit. Consistent lubricant use was evaluated with logistic regression. Consistent lubricant use was reported by 77.0% of men and associated with consistent condom use with casual partners, while binge drinking, payment for sex, and inconsistent condom use with casual, and steady partners, were negatively associated. Though consistent lubricant use is common among this Thai MSM cohort, further promotion is needed with MSM engaging in risky sexual practices.

BACKGROUND: Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infection are prevalent among men who have sex with men (MSM) and may infect multiple anatomic sites. We measured site-specific prevalence and correlates of CT and NG infection among Bangkok MSM Cohort Study participants. METHODS: In April 2006 to November 2010, 1744 men enrolled in the Bangkok MSM Cohort Study. Participants provided historical information and underwent physical examination. Rectal, urethral, and pharyngeal CT and NG screening were performed by nucleic acid amplification and/or culture. Logistic regression was used to identify correlates of site-specific CT, NG, and coinfection. RESULTS: Among 1743 participants, 19.2% were infected with CT and/or NG. CT, NG, and CT-NG coinfection were detected in 11.6%, 4.6%, and 2.9%, of participants, respectively. Rectal, urethral, and pharyngeal CT infections were detected in 9.5%, 4.5%, and 3.6% of cases. N. gonorrhoeae was present at these sites in 6.1%, 1.8%, and 0.5% of cases. Most infections were asymptomatic (CT: 95.3%, NG: 83.2%). Rectal CT and NG infections were mutually associated (CT: adjusted odds ratio [AOR], 5.4; 95% confidence interval [CI], 3.4-8.7; NG: AOR, 2.4; 95% CI, 1.1-5.2) and independently associated with HIV infection (CT: AOR, 1.6, 95% CI, 1.0-2.4; NG: AOR, 2.0, 95% CI, 1.3-3.1). Numerous behavioral correlates of infection were observed. CONCLUSIONS: CT and NG infections are highly prevalent among MSM in Bangkok, most frequently affect the rectum, and are most often asymptomatic. Routine screening of asymptomatic MSM for CT and NG infection should include rectal sampling and focus on men with HIV and a history of other sexually transmitted infections.

Rectal microbicides (RMs) hold promise as a HIV prevention method to reduce transmission among men who have sex with men (MSM). To assess RM trial feasibility in Bangkok, we measured prevalence and correlates of willingness to participate among Thai MSM observational cohort participants. Between April 2006 and December 2010, 1744 MSM enrolled in the Bangkok MSM Cohort Study; at 12 months, RM trial participation willingness was measured. We evaluated correlates of RM trial participation willingness using logistic regression analysis. Participants completing the 12-month visit (81.4%, n = 1419) had a mean age of 27.3 years (SD = 6.1), and 65.5% and 86.1% reported having a steady partner or anal intercourse (AI) in the past four months, respectively. Most (79.1%, n = 1123) participants reported willingness to participate in an RM trial, which, in multivariable analysis, was independently associated with insertive only (adjusted odds ratio [AOR] = 3.25, 95% CI: 1.82-5.81) or receptive/versatile role AI (AOR = 3.07, 95% CI: 1.88-5.01), and being paid for sex (AOR = 12.15, 95% CI: 1.67-88.21) in the past four months, and believing that people with AIDS look sick (AOR = 1.92, 95% CI: 1.23-2.98). Of hypothetical RM trial features to increase enrollment likelihood, the most (91.1%) compelling was that the study be approved by the Thai ethics committee, followed by the study site offering evening hours (88.9%). Reasons not to participate were not wanting a rectal examination (29.5%) or fluid collected from the penis or anus (24.6%) and not wanting the placebo (23.0%). RM trial participation willingness was high, particularly for those with greater HIV acquisition risk, within this Thai MSM cohort, suggesting feasibility of an RM trial. Addressing potential barriers to trial entry may be useful in educational materials to optimize recruitment.