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.

Screening for Chlamydia trachomatis and Neisseria gonorrhoeae infection among asymptomatic men who have sex with men in Bangkok, Thailand.

We report positivity rates of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infection at each anatomic site among asymptomatic men who have sex with men (MSM). We calculated the number needed to screen (NNS) to detect CT and NG infection at each anatomic site. From 2006 to 2010, we enrolled Thai MSM, age ≥ 18 years into the Bangkok MSM Cohort Study. Participants underwent physical examination and had rectal, urethral, and pharyngeal screening for CT and NG infection using nucleic acid amplification tests (NAATs). Of 1744 enrollees, 1696 (97.2%) had no symptoms of CT and NG infection. The positivity rates of CT and NG infection at any site were 14.3% (rectum, urethra, pharynx) and 6.4% (rectum, urethra), respectively. The NNS to detect rectal CT and rectal NG infections was 10 and 16, respectively (p < 0.05). For urethral infection, the NNS of CT was lower than the NNS of NG (22, 121: p < 0.05). The lowest NNS found for rectal CT infection was in HIV-infected MSM (6, 5-8). Asymptomatic CT and NG infection were common among MSM in Bangkok, Thailand and frequently detected in the rectum. In setting where screening in all specimens using NAAT is not feasible, rectal screening should be a priority.

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.

Self-collected genital swabs compared with cervicovaginal lavage for measuring HIV-1 and HSV-2 and the effect of acyclovir on viral shedding.

HIV-1 and HSV-2 are frequent genital co-infections in women. To determine how self-collected genital swabs compare to provider-collected cervicovaginal lavage, paired self-collected genital swabs and cervicovaginal lavage from women co-infected with HIV-1 and HSV-2 were evaluated. Women were in an acyclovir clinical trial and their samples were tested for HIV-1 RNA (361 samples) and HSV-2 DNA (378 samples). Virus shedding, quantity and acyclovir effect were compared. HIV-1 and HSV-2 were more frequently detected in self-collected genital swabs: 74.5% of self-collected genital swabs and 63.6% of cervicovaginal lavage had detectable HIV-1 (p ≤ 0.001, Fisher's exact test) and 29.7% of self-collected genital swabs and 19.3% of cervicovaginal lavage had detectable HSV-2 (p ≤ 0.001) in the placebo month. Cervicovaginal lavage and self-collected genital swabs virus levels were correlated (Spearman's rho, 0.68 for HIV; 0.61 for HSV-2) and self-collected genital swabs levels were generally higher. In multivariate modeling, self-collected genital swabs and cervicovaginal lavage could equally detect the virus-suppressive effect of acyclovir: for HIV-1, proportional odds ratios were 0.42 and 0.47 and for HSV-2, they were 0.10 and 0.03 for self-collected genital swabs and cervicovaginal lavage, respectively. Self-collected genital swabs should be considered for detection and measurement of HIV-1 and HSV-2 in clinical trials and other studies as they are a sensitive method to detect virus and can be collected in the home with frequent sampling.

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.

Randomized Controlled Trial to Compare Immunogenicity of Standard-Dose Intramuscular Versus Intradermal Trivalent Inactivated Influenza Vaccine in HIV-Infected Men Who Have Sex With Men in Bangkok, Thailand.

BACKGROUND: Individuals infected with human immunodeficiency virus (HIV) are at increased risk for severe influenza, yet immune responses to standard-dose intramuscular (IM) influenza vaccine are suboptimal in this population. Intradermal (ID) delivery of influenza vaccine might improve immune response through enhanced stimulation of dendritic cells. METHODS: We conducted a randomized, double-blind, controlled trial to compare the immunogenicity of off-label standard-dose (15 µg) ID vs standard-dose (15 µg) IM inactive influenza vaccine in HIV-infected men in Bangkok, Thailand. The primary study outcome was seroconversion (minimum titer of 1:40 and ≥4-fold rise in antibody titer) at 1 month postvaccination based on serum hemagglutination inhibition antibody titers against each vaccine strain. Adverse events (AEs) in the 7 days following vaccination were also assessed. RESULTS: We enrolled 400 HIV-infected participants; 200 were randomly assigned to receive IM and 200 ID vaccine. Vaccine arms were well-balanced with respect to age, CD4 cell count, HIV RNA load, and antiretroviral treatment. Percentage of seroconversion to all (ID 14% vs IM 15%; P = .8) or at least 1 (ID 69% vs IM 68%; P = .7) of the 3 vaccine strains did not differ significantly between ID vs IM vaccine recipients. A higher proportion of participants who received ID vaccine had mild injection-site AEs compared with participants who received IM vaccine (77% vs 27%). CONCLUSIONS: There were no significant differences in the immunogenicity of standard-dose ID vs IM influenza vaccine in this HIV-infected population in Thailand. Additional strategies to enhance immune responses to influenza vaccine among HIV-infected persons are needed. CLINICAL TRIALS REGISTRATION: NCT01538940.

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.

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.

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.

Cyclic changes in HIV shedding from the female genital tract during the menstrual cycle.

Factors increasing genital human immunodeficiency virus (HIV) shedding may increase female-to-male HIV transmission risk. We examined HIV shedding in 67 women with HIV type 1 and herpes simplex virus type 2 coinfection, during 2 menstrual cycles. Shedding occurred in 60%, 48%, and 54% of samples during the follicular, periovulatory, and luteal phases, respectively (P = .01). Shedding declined after menses until ovulation, with a slope -0.054 log10 copies/swab/day (P < .001), corresponding to a change of approximately 0.74 log10 copies between peak and nadir levels. Shedding increased during the luteal phase only among women with CD4 counts of <350 cells/µL. In reproductive-aged women, shedding frequency and magnitude are greatest immediately following menses and lowest at ovulation.

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.

UC781 microbicide gel retains anti-HIV activity in cervicovaginal lavage fluids collected following twice-daily vaginal application.

The potent nonnucleoside reverse transcriptase inhibitor UC781 has been safety tested as a vaginal microbicide gel formulation for prevention of HIV-1 sexual transmission. To investigate whether UC781 retained anti-infective activity following exposure to the female genital tract, we conducted an ex vivo analysis of the UC781 levels and antiviral activity in cervicovaginal lavage (CVL) fluids from 25 Thai women enrolled in a 14-day safety trial of twice-daily vaginal application of two concentrations of the UC781 microbicide gel. CVL samples were collected from women in the 0.1% (n = 5), 0.25% (n = 15), and placebo (n = 5) gel arms following the first application of gel (T(15 min)) and 8 to 24 h after the final application (T(8-24 h)) and separated into cell-free (CVL-s) and pelletable (CVL-p) fractions. As UC781 is highly hydrophobic, there were significantly higher levels of UC781 in the CVL-p samples than in the CVL-s samples for the UC781 gel arms. In T(8-24 h) CVL-p samples, 2/5 and 13/15 samples collected from the 0.1% and 0.25% UC781 gel arms, respectively, efficiently blocked infection with ≥ 4 log(10) 50% tissue culture infective dose (TCID(50)) of a CCR5-tropic CRF01_AE HIV-1 virus stock. Independent of the arm, the 11 CVL-p samples with UC781 levels of ≥ 5 µg/CVL sample reduced infectious HIV by ≥ 4 log(10) TCID(50). Our results suggest that the levels and anti-infective activities of UC781 gel formulations are likely to be associated with a cellular or pelletable component in CVL samples. Therefore, cellular and pelletable fractions should be assayed for drug levels and anti-infective activity in preclinical studies of candidate microbicides.

HIV drug resistance threshold survey using specimens from voluntary counselling and testing sites in Hanoi, Vietnam.

BACKGROUND: In countries where antiretroviral therapy has been available or is being rapidly expanded, the World Health Organization (WHO) recommends surveillance for transmitted HIV drug resistance (HIVDR) by threshold surveillance methods using specimens from antenatal clinics or voluntary counselling and testing (VCT) sites. The aim of this study was to implement the HIVDR threshold survey in VCT sites in Vietnam, where HIV prevalence is high. Estimating transmitted resistance in the infected population will enable the appropriateness of current antiretroviral drug regimens to be assessed and will inform plans for future HIVDR surveillance. METHODS: Consecutive blood specimens were collected from 70 newly diagnosed HIV-positive clients 18-24 years of age at two sites in Hanoi, Vietnam. Informed consent and serum specimens were obtained from each eligible client, with serum frozen at -70 degrees C until shipping to Thailand for resistance testing using the TruGene system. RESULTS: From February until August 2006, 559 clients were eligible to participate in this survey. Of the 535 clients (95.7%) who agreed to participate, 70 (13%) were HIV-positive and were included in the survey. Of the 70 specimens sent for genotyping, 52 consecutive samples were amplified, 49 of which could be genotyped. Only 1 of 49 genotyped specimens had mutations associated with drug resistance (L74V and Y181C) in the reverse transcriptase gene, indicating that the prevalence of transmitted HIVDR to all drugs and drug classes evaluated was <5%. CONCLUSION: The prevalence of transmitted HIVDR was low in Hanoi as determined using threshold surveillance methods. The Ministry of Health plans to repeat this survey methodology in one more province and to confirm these findings by expanded HIVDR surveillance.