BACKGROUND: Differences between HIV genotypes may affect HIV disease progression. We examined infecting HIV genotypes and their association with disease progression in a cohort of men who have sex with men with incident HIV infection in Bangkok, Thailand. METHODS: We characterized the viral genotype of 189 new HIV infections among MSM identified between 2006-2014 using hybridization and sequencing. Plasma viral load (PVL) was determined by PCR, and CD4+ T-cell counts were measured by flow cytometry. We used Generalized Estimating Equations to examine factors associated with changes in CD4+ T-cell counts. Factors associated with immunologic failure were analyzed using Cox proportional hazard models. RESULTS: Among 189 MSM, 84% were infected with CRF01_AE, 11% with recombinant B/CRF01_AE and 5% with subtype B. CD4+ T-cell decline rates were 68, 65, and 46 cells/muL/year for CRF01_AE, recombinants, and subtype B, respectively, and were not significantly different between HIV subtypes. CD4+ T-cell decline rate was significantly associated with baseline PVL and CD4+ T-cell counts (p <0.001). Progression to immunologic failure was associated with baseline CD4+ T-cell </= 500 cells/muL (AHR 1.97; 95% CI 1.14-3.40, p = 0.015) and PVL > 50,000 copies/ml (AHR 2.03; 1.14-3.63, p = 0.017). There was no difference in time to immunologic failure between HIV subtypes. CONCLUSION: Among HIV-infected Thai MSM, low baseline CD4+ T-cell and high PVL are associated with rapid progression. In this cohort, no significant difference in CD4+ T-cell decline rate or time to immunologic failure was seen between CRF01_AE and other infecting HIV subtypes.

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.

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/muL vs. 431 cells/muL 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 >1550mg/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.

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.

Coinfection with HIV and hepatitis B virus (HBV) is common in resource-limited settings but is frequently not diagnosed. The authors retrospectively tested specimens for HBV in HIV-infected Thai women who had participated in an antiretroviral therapy (ART) clinical study. A substantial proportion (27 of 211; 13%) of HIV-infected women were HBV coinfected. Among HIV/HBV-coinfected women, the authors observed similar rates of antiretroviral-associated liver toxicity (despite nevirapine [NVP] use) and CD4 count reconstitution as observed in HIV-monoinfected women. Hepatitis B surface antigen (HBsAg) screening detected the majority (81%) of HBV coinfections, including all 5 HBV-coinfected women who did not suppress HBV despite 48 weeks of lamivudine (3TC)-containing ART and could be used to tailor ART for patients diagnosed with HBV coinfection in accordance with World Health Organization guidelines. Although HBsAg screening did not diagnose 5 occult HBV coinfections, these women achieved HBV suppression on 3TC-containing ART, suggesting that not detecting occult HBV coinfection would have limited clinical impact.

INTRODUCTION: HIV in Vietnam and Southern China is driven by injection drug use. We have implemented HIV prevention interventions for IDUs since 2002-2003 in Lang Son and Ha Giang Provinces, Vietnam and Ning Ming County (Guangxi), China. METHODS: Interventions provide peer education and needle/syringe distribution. Evaluation employed serial cross-sectional surveys of IDUs 26 waves from 2002 to 2011, including interviews and HIV testing. Outcomes were HIV risk behaviors, HIV prevalence and incidence. HIV incidence estimation used two methods: 1) among new injectors from prevalence data; and 2) a capture enzyme immunoassay (BED testing) on all HIV+ samples. RESULTS: We found significant declines in drug-related risk behaviors and sharp reductions in HIV prevalence among IDUs (Lang Son from 46% to 23% [p<0.001], Ning Ming: from 17% to 11% [p = 0.003], and Ha Giang: from 51% to 18% [p<0.001]), reductions not experienced in other provinces without such interventions. There were significant declines in HIV incidence to low levels among new injectors through 36-48 months, then some rebound, particularly in Ning Ming, but BED-based estimates revealed significant reductions in incidence through 96 months. DISCUSSION: This is one of the longest studies of HIV prevention among IDUs in Asia. The rebound in incidence among new injectors may reflect sexual transmission. BED-based estimates may overstate incidence (because of false-recent results in patients with long-term infection or on ARV treatment) but adjustment for false-recent results and survey responses on duration of infection generally confirm BED-based incidence trends. Combined trends from the two estimation methods show sharp declines in incidence to low levels. The significant downward trends in all primary outcome measures indicate that the Cross-Border interventions played an important role in bringing HIV epidemics among IDUs under control. The Cross-Border project offers a model of HIV prevention for IDUs that should be considered for large-scale replication.

We report prevalence of Treponema pallidum (TP) seropositivity and herpes simplex virus type 2 (HSV-2) infection and risk factors associated with their prevalence in a cohort of men who have sex with men (MSM) in Bangkok, Thailand. Between April 2006 and March 2010 we enrolled Thai MSM into a cohort study based at the Silom Community Clinic, with baseline behavioural data and laboratory testing for sexually transmitted infections (STIs). Logistic regression was used to analyse risk factors associated with the prevalence of TP seropositivity and HSV-2 infection. From a total of 1544 enrolled men (mean age 26 years) TP, HSV-2 and HIV seropositive rates were 4.4%, 20.7% and 21.6%, respectively. After multivariable analysis, participating in group sex, reporting paying for sex, reporting sex with a casual partner in a park and being HSV-2 seropositive were associated with TP prevalence. Age ≥30 years, having less than a high school education, past use of recreational drugs, meeting casual sexual partners at a public venue (sauna) and TP seropositivity were associated with HSV-2 infection. The significant baseline prevalence of TP seropositivity and HSV-2 infection in this cohort demonstrates the need for screening and treatment of these STIs and targeted prevention interventions in Thai MSM in Bangkok.

BACKGROUND: Performance of the BED assay in estimating HIV-1 incidence has previously been evaluated by using longitudinal specimens from persons with incident HIV infections, but questions remain about its accuracy. We sought to assess its performance in three longitudinal cohorts from Thailand where HIV-1 CRF01_AE and subtype B' dominate the epidemic. DESIGN: BED testing was conducted in two longitudinal cohorts with only incident infections (a military conscript cohort and an injection drug user cohort) and in one longitudinal cohort (an HIV-1 vaccine efficacy trial cohort) that also included long-term infections. METHODS: Incidence estimates were generated conventionally (based on the number of annual serocoversions) and by using BED test results in the three cohorts. Adjusted incidence was calculated where appropriate. RESULTS: For each longitudinal cohort the BED incidence estimates and the conventional incidence estimates were similar when only newly infected persons were tested, whether infected with CRF01_AE or subtype B'. When the analysis included persons with long-term infections (to mimic a true cross-sectional cohort), BED incidence estimates were higher, although not significantly, than the conventional incidence estimates. After adjustment, the BED incidence estimates were closer to the conventional incidence estimates. When the conventional incidence varied over time, as in the early phase of the injection drug user cohort, the difference between the two estimates increased, but not significantly. CONCLUSIONS: Evaluation of the performance of incidence assays requires the inclusion of a substantial number of cohort-derived specimens from individuals with long-term HIV infection and, ideally, the use of cohorts in which incidence remained stable. Appropriate adjustments of the BED incidence estimates generate estimates similar to those generated conventionally.