Risk Behaviors Among Young Men Who Have Sex With Men in Bangkok: A Qualitative Study to Understand and Contextualize High HIV Incidence.

The Bangkok Men Who Have Sex With Men (MSM) Cohort Study has shown high HIV incidence (8-12/100 person-years) among 18-21-year-old MSM. These data led to a further study using qualitative methods among young (18-24 years old) MSM in order to understand the factors driving the HIV epidemic among YMSM. We conducted eight focus group discussions and 10 key informant interviews among YMSM in Bangkok, Thailand. Sociodemographic and behavioral data were collected using a questionnaire. We audio-recorded, transcribed, and analyzed qualitative and questionnaire data using computer software. The categories relating to risk behavior were (1) the use of social networks for seeking sexual partners and the marketing promotions of MSM entertainment venues, (2) social influence by peers and older MSM, (3) easy access to high parties and group sex, (4) easy access to club drugs, (5) conceptions related to HIV risk, and (6) sexual preferences of YMSM. Increased HIV testing, same-sex education, and YMSM-specific HIV prevention efforts are urgently needed for YMSM in Bangkok.

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.

Hepatitis B vaccination uptake and correlates of serologic response among HIV-infected and uninfected men who have sex with men (MSM) in Bangkok, Thailand.

BACKGROUND: Vaccination against hepatitis B virus (HBV) is recommended for all HBV-susceptible men who have sex with men (MSM). There is limited information on correlates of immunity to HBV vaccination in this group. We present serologic response rates to hepatitis B vaccine and identify factors associated with impaired response among HIV-uninfected and HIV-infected Thai MSM. METHODOLOGY: HBV-susceptible volunteers were offered hepatitis B vaccination at months zero, one, and six. We measured baseline (pre-vaccination) total serum IgG and IgG subclasses (all participants), baseline CD4 count, and plasma HIV-1 viral load (PVL) (HIV+ participants). HBV serologies were retested at 12 months. Serologic responses were compared between all groups in men receiving three vaccine doses. RESULTS: 511/651 HIV-negative and 64/84 HIV-positive participants completed the three-dose series. Response rates in HIV-uninfected and -infected participants were 90.1% vs. 50.0% (p<0.0001). Median pre-vaccination IgG was higher among non-responders than responders overall (1238.9.0 vs. 1057.0mg/dL, p=0.003) and among HIV-infected participants (1534.0 vs. 1244.5mg/dL, p=0.005), but not significantly among HIV-uninfected participants (1105.5 vs. 1054.3mg/dL, p=0.96). Pre-vaccination IgG1 and IgG3 levels were higher among HIV-positive than HIV-negative participants (median 866.0 vs. 520.3, and 105.8 vs. 83.1mg/dL, respectively, p<0.0001). Among HIV-infected participants, median CD4 count in non-responders was 378 cells/µL vs. 431 cells/µL in responders (p=0.20). Median PVL in non-responders was 64,800 copies/mL vs. 15500 copies/mL in responders (p=0.04). Participants with pre-vaccination plasma IgG >1550 mg/dL and PVL >10,000 copies/mL were almost always non-responsive (p<0.01). CONCLUSIONS: HIV infection was associated with poor vaccine responses. High plasma viral load, elevated pre-vaccination total serum IgG and elevated pre-vaccination IgG1 are associated with poorer response to vaccination among HIV-infected MSM. In this group, the combination of high PVL and pre-vaccination total IgG is highly predictive of vaccine failure.

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.

Lubricant Use Among Men Who Have Sex With Men Reporting Anal Intercourse in Bangkok, Thailand: Impact of HIV Status and Implications for Prevention.

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 was 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.

Prevalence of Anal Human Papillomavirus Vaccine Types in the Bangkok Men Who Have Sex With Men Cohort Study.

BACKGROUND: The quadrivalent human papillomavirus (qHPV) and 9 valent (nHPV) vaccine are licensed for males to prevent anal HPV-associated dysplasia and cancer caused by HPV types 6, 11, 16, and 18 (qHPV) and additional types 33, 35, 45, 52, and 58 (nHPV), respectively. Both conditions are common in HIV-infected and HIV-uninfected men who have sex with men (MSM). It is not well documented which anal HPV vaccine types are most prevalent in Southeast Asia. METHODS: A convenience sample of 400 anal swabs were obtained from 200 HIV-infected and 200 HIV-uninfected sexually active Bangkok MSM Cohort Study participants. After swab collection in PreservCyt (Cytyc Corp, Marlborough, MA), the media was stored at -80°C until processing. DNA was extracted, amplified by polymerase chain reaction, denatured, and then hybridized to probes for 37 HPV types and ß-globin. RESULTS: The mean participant age was 25.6 years (range, 18-55 years); the mean CD4 T-cell count was 410 cells/mm in the HIV-infected participants. Among all swab samples, 386 (192 HIV-positive and 194 HIV-negative) had adequate ß-globin for HPV genotype testing. Anal HPV type was detected in 44.3% of participants whose samples underwent genotype testing. Both qHPV and nHPV types were more frequently detected in HIV-infected compared with HIV-uninfected (42.2% vs. 23.2% [P < 0.01], 50.0% vs. 24.2% [P < 0.01]), respectively). There were no significant relationships between social behaviors (alcohol use, drug use) or sexual behaviors (number of partners, condom usage, sexual positioning) and anal HPV prevalence. CONCLUSIONS: The prevalence of anal vaccine HPV types in Thai MSM was similar to that reported in MSM from Western populations and has a similar distribution by HIV status. Targeting young MSM with vaccination could offer protection against HPV vaccine types.

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.

Prevalence and Correlates of Chlamydia trachomatis and Neisseria gonorrhoeae by Anatomic Site Among Urban Thai Men Who Have Sex With Men.

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.

Longitudinal analysis of key HIV-risk behavior patterns and predictors in men who have sex with men, Bangkok, Thailand.

The HIV incidence among Thai men who have sex with men (MSM) enrolled in the Bangkok MSM Cohort Study (BMCS) has remained high since its inception in 2006. The purpose of this BMCS analysis was to determine: (1) changes in three HIV-risk behaviors (unprotected anal intercourse (UAI), recreational drug use, and multiple sexual partners i.e., more than four male/transgender partner) over time; and (2) factors associated with each one separately. Thai MSM aged 18 years or older and living in Bangkok were eligible to participate in the BMCS. At each follow-up visit, participants were asked to report their sexual and drug behaviors in the previous 4 months. We conducted a longitudinal analysis using generalized estimating equations logistic regression that included 1,569 MSM who were enrolled from 2006 to 2010 and contributed at least one follow-up visit. For each four-month visit increase, we found a 2, 1, and 1 % decrease in odds for reported UAI, recreational drug use, and multiple sexual partners, respectively. We found significant predictors associated with three HIV-risk behaviors such as binge drinking, participation in group sex, and use of erectile dysfunction drugs. The statistically significant decrease in odds of HIV-risk behaviors among the participants is encouraging; however, continued vigilance is required to address the factors associated with HIV-risk behaviors through currently available interventions reaching MSM.

Increasing HIV-1 molecular complexity among men who have sex with men in Bangkok.

In Thailand, new HIV-1 infections are largely concentrated in certain risk groups such as men who have sex with men (MSM), where annual incidence may be as high as 12% per year. The paucity of information on the molecular epidemiology of HIV-1 in Thai MSM limits progress in understanding the epidemic and developing new prevention methods. We evaluated HIV-1 subtypes in seroincident and seroprevalent HIV-1-infected men enrolled in the Bangkok MSM Cohort Study (BMCS) between 2006 and 2011. We characterized HIV-1 subtype in 231 seroprevalent and 194 seroincident subjects using the multihybridization assay (MHA). Apparent dual infections, recombinant strains, and isolates found to be nontypeable by MHA were further characterized by targeted genomic sequencing. Most subjects were infected with HIV-1 CRF01_AE (82%), followed by infections with recombinants (11%, primarily CRF01_AE/B recombinants), subtype B (5%), and dual infections (2%). More than 11 distinct chimeric patterns were observed among CRF01B_AE/B recombinants, most involving recombination within integrase. A significant increase in the proportion of nontypeable strains was observed among seroincident MSM between 2006 and 2011. CRF01_AE and subtype B were the most and least common infecting strains, respectively. The predominance of CRF01_AE among HIV-1 infections in Thai MSM participating in the BMCS parallels trends observed in Thai heterosexuals and injecting drug users. The presence of complex recombinants and a significant rise in nontypeable strains suggest ongoing changes in the genetic makeup of the HIV-1 epidemic in Thailand, which may pose challenges for HIV-1 prevention efforts and vaccine development.

Prevalence and correlates of willingness to participate in a rectal microbicide trial among men who have sex with men in Bangkok.

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.

Hepatitis A and hepatitis B infection prevalence and associated risk factors in men who have sex with men, Bangkok, 2006-2008.

Despite the availability of safe and effective vaccines, little is known about prevalence and risk factors for hepatitis A (HAV) and hepatitis B virus (HBV) infection among Thai men who have sex with men. The prevalence of HAV and HBV infection among men who have sex with men cohort in Bangkok was assessed. Baseline blood specimens were drawn and demographic and behavioral data were collected. Bivariate and multivariate logistic regression analysis was used to analyze risk factors for prevalent HAV and HBV infection. One thousand two hundred ninety-nine Thai men who have sex with men 18 years and older were enrolled. Among those with results, 349/1,291 (27.0%) had evidence of past or current hepatitis A infection. Of the 1,117 (86.5%) men with unambiguous HBV test results, 442 (39.6%) had serologic evidence of past/current infection, 103 (9.2%) were immune due to hepatitis B vaccination, 572 (51.2%) had no evidence of immunological exposure to HBV or vaccine. Of those with past/current HBV infection, 130 (29.4%) were HIV positive. Age >35 years was independently associated with both HAV and HBV infection. University education was protective against both HAV and HBV infection. Increased alcohol consumption, number of lifetime male sexual partners ≥10, and prevalent HIV infection were also independently associated with HBV infection. The prevalence of past/current HAV and HBV infection was high in Bangkok men who have sex with men. Age-cohorts with a higher prevalence of hepatitis B vaccine induced immunity may be expected in the future. Hepatitis A and B vaccination is recommended.

Evidence of an explosive epidemic of HIV infection in a cohort of men who have sex with men in Thailand.

OBJECTIVE: To assess HIV-prevalence, incidence and risk factors in a cohort of men who have sex with men (MSM) in Bangkok. DESIGN: : Cohort study with 4-monthly follow-up visits conducted between April 2006 and July 2012 at a dedicated study clinic in a central Bangkok hospital. Participants were 1744 homosexually active Thai men, at least 18 years old and residents of Bangkok. METHODS: Men were tested for HIV-infection at every study visit and for sexually transmitted infections at baseline. Demographic and behavioural data were collected by audio-computer-assisted self-interview. Logistic regression analysis was used to evaluate risk factors for HIV-prevalence and Cox proportional hazard analysis to evaluate risk factors for HIV-incidence. RESULTS: Baseline HIV-prevalence was 21.3% (n = 372) and 60 months cumulative HIV-incidence was 23.9% (n = 222). Overall HIV-incidence density was 5.9 per 100 person-years. Multivariate risk factors for HIV-prevalence were older age, secondary/vocational education (vs. university or higher), employed or unemployed (vs. studying), nitrate inhalation, drug use for sexual pleasure, receptive anal intercourse, history of sexual coercion, no prior HIV-testing, and anti-HSV-1 and 2 and Treponema pallidum positivity at baseline. Multivariate risk factors for HIV-incidence were younger age, living alone or with roommate (vs. with a partner or family), drug use for sexual pleasure, inconsistent condom use, receptive anal intercourse, group sex, and anti-HSV-1 and 2 and T. pallidum positivity at baseline. Having no anal intercourse partners was inversely associated with HIV-incidence. CONCLUSION: The high HIV prevalence and incidence in this cohort of Bangkok MSM documents an explosive epidemic. Additional preventive interventions for MSM are urgently needed.

Acceptability of Carraguard vaginal microbicide gel among HIV-infected women in Chiang Rai, Thailand.

BACKGROUND: Few studies of microbicide acceptability among HIV-infected women have been done. We assessed Carraguard® vaginal gel acceptability among participants in a randomized, controlled, crossover safety trial in HIV-infected women in Thailand. METHODOLOGY/PRINCIPAL FINDINGS: Participants used each of 3 treatments (Carraguard gel, methylcellulose placebo gel, and no product) for 7 days, were randomized to one of six treatment sequences, and were blinded to the type of gel they received in the two gel-use periods. After both gel-use periods, acceptability was assessed by face-to-face interview. Responses were compared to those of women participating in two previous Carraguard safety studies at the same study site. Sixty women enrolled with a median age of 34 years; 25% were sexually active. Self-reported adherence (98%) and overall satisfaction rating of the gels (87% liked "somewhat" or "very much") were high, and most (77%) considered the volume of gel "just right." For most characteristics, crossover trial participants evaluated the gels more favorably than women in the other two trials, but there were few differences in the desired characteristics of a hypothetical microbicide. Almost half (48%) of crossover trial participants noticed a difference between Carraguard and placebo gels; 33% preferred Carraguard while 12% preferred placebo (p = 0.01). CONCLUSIONS/SIGNIFICANCE: Daily Carraguard vaginal gel use was highly acceptable in this population of HIV-infected women, who assessed the gels more positively than women in two other trials at the site. This may be attributable to higher perceived need for protection among HIV-infected women, as well as to study design differences. This trial was registered in the U.S. National Institutes of Health clinical trials registry under registration number NCT00213044.

Carraguard acceptability among men and women in a couples study in Thailand.

OBJECTIVE: The aim of this study is to evaluate the use and acceptability of Carraguard among men and women enrolled as couples in a microbicide trial. MATERIALS AND METHODS: Focus groups were conducted with participants in a 6-month randomized, placebo-controlled trial that enrolled sexually active, low-risk couples in Thailand. Participants were blinded as to which gel they had received at the time of the discussions. RESULTS: Most men and women liked the gel and found it acceptable. The majority of men and women thought that using the gel increased sexual pleasure, although participants disagreed about whether using the gel increased sexual frequency. Drawbacks of gel use included that it was too wet or messy, and nearly all respondents thought that the applicator was too hard. Most men and women questioned the utility of using the gel among married couples since gel use was tied to perception of HIV/STI risk. However, those who perceived themselves to be at risk expressed interest in using the product as an alternative to condoms. Many women were particularly interested in a product that also had contraceptive properties. Gel use also raised issues of trust and fidelity among couples and questions about men's ability to detect women's use of the product. CONCLUSION: Men and women in this study found the gel acceptable and thought that it should be made available if it is found to be safe and effective. Strategies for marketing a potential microbicide product must take the target population into consideration. For married couples, key considerations may be partner dynamics and trust issues, whereas messages focusing on sexual pleasure or disease prevention may resonate more strongly with sex workers or other populations.

Sex frequency and sex planning among men who have sex with men in Bangkok, Thailand: implications for pre- and post-exposure prophylaxis against HIV infection.

BACKGROUND: Daily HIV antiretroviral pre-exposure prophylaxis (PrEP) is being evaluated in clinical trials among men who have sex with men (MSM). However, daily PrEP may not be congruent with sexual exposure profiles of MSM. Here, we investigate sex frequency and sex planning to identify and inform appropriate PrEP strategies for MSM. METHODS: We evaluated sex frequency and sex planning in a cohort of HIV-negative MSM in Bangkok, Thailand. Chi-squared test was used to compare reports of sex on different weekdays; logistic regression was used to identify predictors of sex frequency and sex planning. RESULTS: Of 823 MSM (with a mean age of 28.3 years), 86% reported having sex on two days per week or less, and 65% reported their last sex to have been planned. Sex on the weekend (approximately 30%) was more often reported than sex on weekdays (approximately 23%). In multivariate analysis, use of alcohol, erectile dysfunction drugs, group sex, sex with a foreigner, buying and selling sex, and a history of HIV testing were associated with having sex on three days or more per week. Being aged 22 to 29 years, not identifying as homosexual, having receptive anal intercourse, and not engaging in group sex were associated with unplanned sex. CONCLUSIONS: Intermittently dosed PrEP (as opposed to daily) may be a feasible HIV prevention strategy and should be considered for evaluation in clinical trials. Risk factors for sex frequency and sex planning may help to identify those in need for daily PrEP and those who may not be able to take a timely pre-exposure dose.

HIV genital shedding and safety of Carraguard use by HIV-infected women: a crossover trial in Thailand.

OBJECTIVE: To evaluate the safety, including impact on genital HIV RNA shedding, of Carraguard vaginal gel in HIV-infected women. DESIGN: This is a randomized, controlled, crossover study of Carraguard in HIV-infected women in Thailand. METHODS: Each woman (CD4 cell count 51-500 cells/microl and not on antiretroviral therapy) used each treatment (Carraguard, methylcellulose placebo, and no-product) once daily for 7 days during each 1-month period (3-week wash-out). Women were randomized to one of the six possible treatment sequences. Safety assessments were conducted at baseline (pregel), 15 min postgel, day 7, and day 14, and included HIV RNA measurements in cervicovaginal lavage (CVL) specimens. RESULTS: Sixty women were enrolled, and 99% of scheduled study visits were completed. At baseline, median age (34 years), CD4 lymphocyte count (296 cells/microl), plasma HIV viral load (4.6 log10 copies/ml), CVL HIV viral load (3.1 log10 total copies per CVL), and sexual behaviors were similar among randomization groups. HIV viral load, leukocyte and hemoglobin levels, and epithelial cell counts in CVLs were lower 15 min after application of Carraguard or placebo compared with no product; CVL HIV viral load was still lower at day 7 but returned to baseline by day 14. Carraguard use was not associated with prevalent or incident genital findings or abnormal vaginal flora. CONCLUSION: Carraguard appears to be well tolerated for once-daily vaginal use by HIV-infected women. The observed reduction in CVL HIV viral load in the gel months may be clinically relevant but could have resulted from interference with sample collection by study gels.

Acceptability of a carrageenan-based candidate vaginal microbicide and matching placebo: findings from a phase II safety trial among women in Chiang Rai, Thailand.

OBJECTIVE: To evaluate extended acceptability of vaginal use of a carrageenan-based candidate microbicide and placebo in northern Thai women. METHODS: As part of a randomized, placebo-controlled, triple-blinded clinical trial, women were asked to insert gel with each vaginal sex act and at least three times per week for 1 year. Used applicators were collected monthly; acceptability questions were asked quarterly. RESULTS: One hundred sixty-five women were enrolled (83 microbicide, 82 placebo); 148 (90%) remained in the study for 12 months. Gel use was high, with > or =87% returning at least three used applicators per week at each visit. Although acceptability was generally high, some decline in positive reporting was noted in terms of ease of application, timing of gel insertion, and gel volume over time. Approximately one quarter reported gel use increased her sexual pleasure. Over one quarter reported that gel volume of 5 mL was too much. All women with a steady partner at 12 months reported talking to their partner about using the gel. Only 2 women spontaneously mentioned being able to use a product covertly as one of the most appealing attributes of a potential microbicide. CONCLUSIONS: Although women in this study generally reported high acceptability and use, some found 5 mL of gel to be too much. Focusing on enhanced sexual pleasure and lubrication may be beneficial for marketing proven microbicides. Development of products will need to balance lubrication and efficacy with perceptions of too much volume. The ability to use a product covertly was not a high priority in this population.

Increase in sexual risk behavior and prevalence of Chlamydia trachomatis among adolescents in Northern Thailand.

BACKGROUND: Monitoring changes in adolescent sexual risk behaviors and sexually transmitted infections is critical for evaluating the effectiveness of human immunodeficiency virus and other prevention programs, but population-based data on adolescents in Thailand are limited. We report findings from 2 cross-sectional surveys conducted in 1999 and 2002 among 15-to 21-year-old vocational students. METHODS: In 1999 and 2002, 1725 and 966 students, respectively, were interviewed using computer-assisted self-interview methods. Urine samples were collected and tested for Chlamydia trachomatis and Neisseria gonorrhoeae by polymerase chain reaction. RESULTS: From 1999 to 2002 C. trachomatis prevalence increased from 3.2% to 7.5% (P <0.001) in women and from 2.5% to 6.0% (P <0.001) in men. There was an increase in the reported mean lifetime number of steady sexual partners among both men (3.4-4.7, P = 0.01) and women (2.5-3.3, P <0.001), and in the mean lifetime number of casual partners among men (1.1-2.1, P <0.001) and women (0.3-1.1, P = 0.04). Reported consistent condom use decreased significantly among women with casual partners (43%-19%, P = 0.03) but not among men (25%-31%, P = 0.31). CONCLUSIONS: Our study identified important increases in the prevalence of chlamydial infection and in sexual risk behaviors among Thai adolescents over a 3-year period. These findings are consistent with other studies suggesting profound social changes are changing norms of adolescent sexual behavior in Thailand, and highlight the need for adolescent sexual health services and prevention programming.

A randomized, placebo-controlled trial to assess the safety and acceptability of use of carraguard vaginal gel by heterosexual couples in Thailand.

OBJECTIVES: To determine the safety and acceptability of use of Carraguard, a carrageenan-derived candidate microbicide gel, during sexual intercourse in women and men. STUDY DESIGN: We conducted a 6-month randomized, placebo-controlled trial among sexually active, couples at relatively lower risk for HIV infection in northern Thailand. METHODS: Women inserted 1 applicator of study gel vaginally every time the couple had sex. Safety was assessed by symptom report and genital examination of both partners and by changes in vaginal flora. Acceptability was assessed by participant interview. RESULTS: Overall, 55 couples were randomized, 28 to Carraguard use and 27 to the methyl-cellulose placebo gel group. Retention and study gel use were similarly high in both study groups; use of gel without condoms was reported in more than 95% of vaginal sex acts. The 2 study groups were similar in the proportions of women and men with symptoms or with genital findings without epithelial disruption, of men with findings with epithelial disruption, and of women with abnormal genital flora, whereas more women in the placebo group had findings with epithelial disruption. Women and men in both groups reported that the gel and applicator were acceptable. CONCLUSIONS: Carraguard can safely be used an average of 2 to 3 times per week during sex and is acceptable to Thai women and men.