Prevalence and incidence of anal high-grade squamous intraepithelial lesions in a cohort of cisgender men and transgender women who have sex with men diagnosed and treated during acute HIV acquisition in Bangkok, Thailand

INTRODUCTION

Men who have sex with men (MSM), especially those living with HIV, are at an increased risk of anal cancer. The prevalence and incidence of its precursor, anal high-grade squamous intraepithelial lesions (HSILs), among MSM who started antiretroviral therapy during acute HIV acquisition are yet to be explored.

METHODS

Participants in an acute HIV acquisition cohort in Bangkok, Thailand, who agreed to take part in this study, were enrolled. All participants were diagnosed and started antiretroviral therapy during acute HIV acquisition. Human papillomavirus (HPV) genotyping and high-resolution anoscopy, followed by anal biopsy as indicated, were done at baseline and 6-monthly visits.

RESULTS

A total of 89 MSM and four transgender women were included in the analyses. Median age at enrolment was 26 years. Baseline prevalence of histologic anal HSIL was 11.8%. With a total of 147.0 person-years of follow-up, the incidence of initial histologic anal HSIL was 19.7 per 100 person-years. Factors associated with incident anal HSIL were anal HPV 16 (adjusted hazards ratio [aHR] 4.33, 95% CI 1.03-18.18), anal HPV 18/45 (aHR 6.82, 95% CI 1.57-29.51), other anal high-risk HPV (aHR 4.23, 95% CI 1.27-14.14), syphilis infection (aHR 4.67, 95% CI 1.10-19.90) and CD4 count <350 cells/mm3 (aHR 3.09, 95% CI 1.28-7.48).

CONCLUSIONS

With antiretroviral therapy initiation during acute HIV acquisition, we found the prevalence of anal HSIL among cisgender men and transgender women who have sex with men to be similar to those without HIV. Subsequent anal HSIL incidence, although lower than that of those with chronic HIV acquisition, was still higher than that of those without HIV. Screening for and management of anal HSIL should be a crucial part of long-term HIV care for all MSM.

Pooled Pharyngeal, Rectal, and Urine Specimens for the Point-of-Care Detection of Chlamydia trachomatis and Neisseria gonorrhoeae by Lay Providers in Key Population-Led Health Services in Thailand

Routine testing for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) in people with heightened risk is lacking in Thailand. This study aimed to assess the performance of the Cepheid Xpert CT/NG assay, conducted by key population (KP) lay providers, for CT and NG detection on single-site and pooled specimens from the pharynx, rectum, and urine. Between August and October 2019, 188 men who have sex with men and 11 transgender women were enrolled. Participants collected urine specimens while trained KP lay providers obtained pharyngeal and rectal swabs. Compared to single-site testing with the Abbott RealTime CT/NG assay by medical technologists, the Xpert assay missed one pharyngeal NG infection out of 199 single-site specimens, giving a 93.3% sensitivity for pharyngeal NG and one missed pharyngeal NG infection out of fifty pooled specimens, giving an 88.9% sensitivity for pharyngeal NG. There was no discrepancy between the two assays for CT detection. The Cohen's Kappa coefficient of pooled specimen testing by the Xpert was 0.93 for NG and 1 for CT when compared to single-site testing by Abbott. Implementing pooled specimen testing by KP lay providers can be a cost-saving strategy to enhance the uptake of CT/NG services for populations facing increased risk.

Sexually transmitted infections incidence in young Thai men who have sex with men and transgender women using HIV pre-exposure prophylaxis

BACKGROUND

Sexually transmitted infections are a major public health issue worldwide. HIV pre-exposure prophylaxis (PrEP) use among youth may be associated with increased incidence of sexually transmitted infections (STIs).

OBJECTIVES

To measure the prevalence and incidence of STIs among young men who have sex with men (YMSM) and young transgender women (YTGW) using PrEP.

METHODS

A prospective cohort of 15- to 19-year-old YMSM and YTGW with HIV risk defined as inconsistent condom use and/or multiple sex partners were enrolled. Participants were provided daily oral tenofovir disoproxil fumarate/emtricitabine. STI screening was done at baseline and month 6 for syphilis, urine, and anal swab nucleic acid amplification testing for C. trachomatis (CT) and N. gonorrheaoe (NG).

RESULTS

From March 2018 to June 2019, 200 adolescents (147 MSM and 53 TGW) with a median (IQR) age of 18 years (17-19) were enrolled. STI prevalence was 22.5% (95% CI 16.7-28.3). STI incidence was 25.2 per 100 person-years (95% CI 14.7, 40.3). Factors associated with STI incidence were self-reported >2 sex partners in the past month (unadjusted rate ratio [uRR] 4.6, 95% CI 1.0, 20.6), and moderate PrEP adherence (uRR 7.3, 95% CI 1.6, 32.6).

CONCLUSIONS

STI incidence in YMSM and YTGW PrEP users was high at approximately one in five. Regular screening and treatment of STIs should be implemented in youth HIV prevention packages.

Prevalence and the associated factors of hepatitis B and hepatitis C viral infections among HIV-positive individuals in same-day antiretroviral therapy initiation program in Bangkok, Thailand

Background

Viral hepatitis is highly prevalent among people with HIV (PWH) and can lead to chronic liver complications. Thailand started universal hepatitis B vaccination at birth in 1992 and achieved over 95% coverage in 1999. We explored the prevalence of hepatitis B and C viral infections and the associated factors among PWH from same-day antiretroviral therapy (SDART) service at the Thai Red Cross Anonymous Clinic, Bangkok, Thailand.

Methods

We collected baseline characteristics from PWH enrolled in the SDART service between July 2017 and November 2019. Multivariable logistic regression was performed to determine factors associated with positive hepatitis B surface antigen (HBsAg) and hepatitis C antibody (anti-HCV).

Results

A total of 4011 newly diagnosed PWH who had HBsAg or anti-HCV results at baseline: 2941 men who have sex with men (MSM; 73.3%), 851 heterosexuals (21.2%), 215 transgender women (TGW; 5.4%), and 4 transgender men (0.1%). Median age was 27 years. Overall seroprevalence of HBsAg and anti-HCV were 6.0 and 4.1%, respectively. Subgroup prevalence were 6.2 and 4.7% among MSM, 4.6 and 2.4% among heterosexuals, and 9.3 and 3.7% among TGW, respectively. Factors associated with HBsAg positivity were being MSM, TGW, born before 1992, CD4 count < 200 cells/mm³, and alanine aminotransferase ≥ 62.5 U/L. Factors associated with anti-HCV positivity were being MSM, age > 30 years, alanine aminotransferase ≥ 62.5 U/L, creatinine clearance < 60 ml/min, and syphilis infection.

Conclusions

Around 5–10% of newly diagnosed PWH in Bangkok had hepatitis B viral infection after 25 years of universal vaccination. Anti-HCV positivity was found in 4–5% of PWH who were MSM and TGW. As World Health Organization and Thailand national guidelines already support routine screening of hepatitis B and C viral infections in PWH and populations at increased risk of HIV including MSM and TGW, healthcare providers should reinforce this strategy and provide linkage to appropriate prevention and treatment interventions. Catch-up hepatitis B vaccination should be made available under national health coverage.

Same-day antiretroviral therapy initiation hub model at the Thai Red Cross Anonymous Clinic in Bangkok, Thailand: an observational cohort study

Introduction

WHO has recommended rapid antiretroviral therapy (ART) initiation, including same‐day ART (SDART). However, data on the feasibility in real‐world settings are limited. We implemented a cohort study at a stand‐alone HIV testing centre to examine its applicability and effectiveness.

Methods

Data were collected from the Thai Red Cross Anonymous Clinic in Bangkok, Thailand, between July 2017 and July 2018 from clients who were ART‐naïve and could return for follow‐up visits. Baseline laboratory tests and chest X‐ray were performed according to national guidelines, and clinical eligibility was determined based on physical examination and chest X‐ray findings. Primary outcomes were retention in care and viral load suppression at 3, 6 and 12 months.

Results

During the study period, 2427 people tested HIV positive. Of these, 2107 (2207/2427, 86.8%) met logistical criteria, and 1904 (1904/2427, 78.5%) agreed to SDART. One thousand seven hundred and twenty‐nine (1729/2427, 71.2%) were placed on ART, with 1257 received same‐day initiation and 1576 initiated ART within 7 days; 1198 clients were successfully referred to free, sustained ART sites. Retention among eligible clients who accepted SDART service at months 3, 6 and 12 was 79.8%, 75.2% and 75.3%, respectively.

Conclusions

Same‐day ART initiation hub model at a stand‐alone HIV testing centre in an urban setting in Bangkok, Thailand, is highly feasible and has a potential for scaling up.

Clinical Trial Number

NCT04032028

Ability of Alere™ HIV Combo to diagnose acute HIV infection is based mainly on HIV-1 p24 antigen detection

BACKGROUND

Alere™ HIV Combo is the only rapid and sensitive point-of-care 4th generation (antigen/antibody) HIV test newly available in Thailand which is advantageous of differentiating between positivity of antigen or antibody or both, especially in acute HIV infection (AHI). AHI in this study was defined by positive machine-based 4th generation test with measurable HIV-RNA but negative 3rd generation (IgM/IgG antibody only) tests.

OBJECTIVE

To evaluate the performance characteristics of Alere™ HIV Combo.

METHODS

Fifty stored plasma samples of subjects diagnosed with AHI were used to evaluate Alere™ HIV Combo.

RESULTS

Of the 50 AHI samples, Alere™ HIV Combo was positive in 37 (74%): 5 with antibody positive only (R1), 26 with p24 antigen positive only (R2), and 6 with both p24 antigen and antibody positive (R3). Mean sample/cut-off (S/ CO) ratios from machine-based 4th generation test of R1, R2 and R3 were 21.55, 148.38 and 72.97 respectively as compared to 7.57 for the 13 non-reactive (NR) samples. The corresponding median log10 HIV-RNA of NR, R1, R2 and R3 were 5.59, 5.86, 7.00 and 6.61 copies/mL respectively. R2 and R3 had significantly higher S/CO and HIV-RNA than NR and R1. Alere™ HIV Combo detected mainly p24 antigen in AHI as seen in 32/50 (64%) subjects and could detect 11/50 (22%) antibody in AHI samples which were missed by the two 3rd generation HIV tests used in our testing algorithm.

CONCLUSIONS

Alere™ HIV Combo is the ideal screening test in a setting with high AHI where machine-based 4th generation test is not available.

Human papillomavirus 16 L1 gene methylation as a potential biomarker for predicting anal intraepithelial neoplasia in men who have sex with men (MSM)

The human papillomavirus (HPV) 16 early promoter and L1 gene methylation were quantitatively measured using pyrosequencing assay in anal cells collected from men who have sex with men (MSM) to determine potential biomarkers for HPV-related anal cancer. The methylation patterns of HPV16 genes, including the early promoter (CpG 31, 37, 43, 52, and 58) and L1 genes (CpG 5600, 5606, 5609, 5615, 7136, and 7145), were analyzed in 178 anal samples. The samples were diagnosed as normal, anal intraepithelial neoplasia (AIN) 1, AIN2, and AIN3. Low methylation levels of the early promoter (< 10%) and L1 genes (< 20%) were found in all detected normal anal cells. In comparison, medium to high methylation (≥ 20–60%) in the early promoter was found in 1.5% (1/67) and 5% (2/40) of AIN1 and AIN2-3 samples, respectively. Interestingly, slightly increased L1 gene methylation levels (≥ 20–60%), especially at the HPV16 5’L1 regions CpGs 5600 and 5609, were demonstrated in AIN2-3 specimen. Moreover, a negative correlation between high HPV16 L1 gene methylation at CpGs 5600, 5609, 5615, and 7145 and a percentual CD4 count was found in AIN3 HIV positive cases. When comparing the methylation status of AIN2-3 to that of normal/AIN1 lesions, the results indicated the potential of using HPV16 L1 gene methylation as a biomarker for HPV-related cancer screening.

Uptake of Primary Care Services and HIV and Syphilis Infection among Transgender Women attending the Tangerine Community Health Clinic, Bangkok, Thailand, 2016 - 2019

INTRODUCTION

Transgender women (TGW) need a specific package of primary care services usually not available in the publicly funded healthcare system. In addition, little is known about HIV and syphilis prevalence and incidence in clinic-based samples of TGW. Here we evaluate the uptake of a transgender-specific package of primary care services by TGW in Bangkok, Thailand and assess HIV and syphilis prevalence and incidence among them.

METHODS

Open cohort study of TGW attending services at the Tangerine Community Health Clinic from 2016 to 2019. Cross-sectional and longitudinal analysis of routinely collected clinic data was performed to study trends in the number of clients, clinic visits and HIV and syphilis prevalence and incidence.

RESULTS

During the study period, 2947 TGW clients made a total of 5227 visits to Tangerine. The number of clients significantly increased from 446 in 2016 to 1050 in 2019 (p < 0.001) and the number of visits from 616 to 2198 during the same period (p < 0.001). Prevalence of HIV at first visit was 10.8% and of syphilis 9.8%. HIV incidence was 1.03 per 100 person years (PY) and of syphilis 2.06 per 100 PY of follow-up. From 2016 to 2019, significant decreases occurred in the annual prevalence of HIV from 14.6% to 9.9% (p < 0.01). The annual prevalence of syphilis significantly increased from 6.6% in 2016 to 14.6% in 2018, and then decreased to 7.3% in 2019 (p < 0.001). The annual HIV incidence decreased during 2016 to 2019, from 1.68 to 1.28 per 100 PY, but this reduction was not statistically significant. The annual incidence of treponemal test seroconversion significantly increased from zero in 2016 to 4.55 per 100 PY in 2019 (p < 0.001).

CONCLUSIONS

The increasing uptake of a transgender-specific package of services, including co-located gender affirmative hormone therapy, suggests this may be an effective model in engaging and retaining TGW in primary care. The decrease in HIV prevalence and low HIV incidence across calendar years point at a possible reduction of HIV acquisition among the TGW population served by Tangerine. The increasing prevalence of syphilis suggests ongoing high-risk sexual behaviour and underscores the need for screening and treatment for this infection at the time of delivery of HIV services.

Drug-drug Interactions Among Thai Transgender Women Living with Human Immunodeficiency Undergoing Feminizing Hormone Therapy and Antiretroviral Therapy: The iFACT Study

BACKGROUND

Drug-drug interactions between feminizing hormone therapy (FHT) and antiretroviral therapy (ART) are a major concern among transgender women (TGW), which may lead to suboptimal ART adherence and inappropriate FHT dosage. To evaluate potential drug-drug interactions between FHT and ART, we performed intensive measurements of the pharmacokinetic (PK) parameters of blood tenofovir (TFV), efavirenz (EFV), and estradiol (E2).

METHODS

Twenty TGW with newly diagnosed human immunodeficiency virus (HIV) infection were enrolled. FHT (E2 valerate 2 mg/d and cyproterone acetate 25 mg/d) was prescribed at baseline until week 5 and restarted at week 8. ART (TFV disoproxil fumarate/emtricitabine/EFV at 300/200/600 mg) was initiated at week 3. The E2 PK parameters were measured intensively at weeks 3 (without ART) and 5 (with ART), and TFV and EFV PK parameters were measured intensively at weeks 5 (with FHT) and 8 (without FHT).

RESULTS

The median (interquartile range) age and body mass index were 25.5 (22.5-31.0) years and 20.6 (19.3-23.1) kg/m2, respectively. The differences in geometric mean ratios between weeks 3 and 5 were as follows for E2 area under the curve, maximum concentration, and concentration at 24 hours (C24), respectively: 0.72 (90% confidence interval, .64-.81; P < .001), 0.81 (.72-.92; P = .006), and 0.64 (.50-.83; P = .004). The differences in geometric mean ratios between weeks 5 and 8 were as follows for TFV AUC, TFV C24, and EFV C24: 0.86 (90% confidence interval, .80-.93; P = .002), 0.83 (.75-.93; P = .006), and 0.91 (.85-.97; P = .02).

CONCLUSIONS

Among HIV-positive TGW, E2 PK parameters were significantly lower in the presence of TFV disoproxil fumarate/emtricitabine/EFV, and some TFV and EFV PK parameters were lower in the presence of FHT. Further studies should determine whether these reductions are clinically significant and whether they occur with other FHT or ART regimens.

Incidence and Persistence of High-risk Anogenital Human Papillomavirus Infection Among Female Youth With and Without Perinatally Acquired Human Immunodefiency Virus Infection: A 3-year Observational Cohort Study

BACKGROUND

Female youth with perinatally acquired human immunodeficiency virus (PHIV) may be at higher risk than uninfected youth for persistent anogenital human papillomavirus (HPV) infection, due to prolonged immunodeficiency.

METHODS

A 3-year cohort study was conducted between 2013 and 2017 among Thai and Vietnamese PHIV and HIV-uninfected females 12-24 years, matched by age group and number of lifetime sexual partners. For HPV genotyping, cervical and anal samples were obtained at baseline and annually. Vaginal samples were collected at baseline and every 6 months. Factors associated with high-risk HPV (HR-HPV) persistence and incidence were assessed.

RESULTS

We enrolled 93 PHIV and 99 HIV-uninfected females. Median age was 19 (interquartile range [IQR] 18-20) years. For the 7 HR-HPV types (16, 18, 31, 33, 45, 52, 58) in the nonavalent HPV vaccine, PHIV had significantly higher incidence (P = .03) and persistence (P = .01) than HIV-uninfected youth over a 3-year period. Having HIV (adjusted hazard ratio [aHR] 2.1, 95% confidence interval [CI] 1.1-3.9) and ever using illegal substances (aHR 4.8, 95% CI 1.8-13.0) were associated with incident 7 HR-HPV infections. HIV-positive status (adjusted prevalence ratio [aPR] 2.2, 95% CI 1.5-3.2), recent alcohol use (aPR 1.75, 95% CI 1.2-2.5), and higher number of lifetime partners (aPR 2.0, 95% CI 1.4-3.1, for 3-5 partners; aPR 1.93, 95% CI 1.2-3.2, for ≥6 partners) were significantly associated with persistent 7 HR-HPV infections.

CONCLUSIONS

Female PHIV were at higher risk of having anogenital HR-HPV acquisition and persistence. Primary and secondary prevention programs for HPV infection and HPV-related diseases should be prioritized for PHIV children and youth.

Inflammatory Biomarkers Do Not Differ Between Persistently Seronegative vs Seropositive People With HIV After Treatment in Early Acute HIV Infection

Persistent viral activity may cause enduring seropositivity and inflammation in treated people with HIV (PWH). We compared inflammatory biomarkers between early treated PWH who remained seronegative or seroconverted and found similar levels of D-dimer, soluble cluster of differentiation 14, C-reactive protein, and interleukin-6, indicating that seronegativity does not affect chronic inflammation in early treated PWH.

The validation and evaluation of anti-HIV testing algorithm used in mobile clinic setting for men who have sex with men in metropolitan Bangkok, Thailand

BACKGROUND

Same-day anti-HIV testing algorithm is recommended by Thai National Guidelines. We compared performance characteristics of algorithms used in a mobile clinic and a facility-based clinic for men who have sex with men (MSM) in Bangkok.

METHODS

Mobile clinic samples collected from 4 saunas and 2 spa venues were tested by Alere DetermineTM HIV 1/2, followed by DoubleCheck GoldTM Ultra HIV 1/2 and SD Bioline HIV 1/2 3.0. All samples were re-tested at the Thai Red Cross Anonymous Clinic (TRCAC) by Architect HIV Ag/Ab or Elecsys HIV combi PT, followed by Alere DetermineTM HIV 1/2 and Serodia HIV 1/2. Non-reactive samples were tested by Aptima nucleic acid amplification test (NAAT) and reactive/inconclusive samples were tested by less-sensitive immunoassays (IA) and HIV-1 RNA to detect acute HIV infection (positive NAAT or non-reactive IA/positive HIV-1 RNA).

RESULTS

Of 233 MSM, 36 (15.5%) had HIV infection diagnosed using mobile clinic algorithm. Two additional acute HIV cases (1 positive NAAT and 1 reactive Architect with detectable HIV-1 RNA) were diagnosed using TRCAC algorithm. The mobile clinic algorithm had a sensitivity of 94.9% (95% CI: 82.7, 99.4) and a specificity of 100% (95% CI: 98.1, 100).

CONCLUSION

Use of whole blood on rapid test kits demonstrated satisfactory performance and allowed same-day HIV test result through a mobile clinic model. For populations with high HIV incidence, careful history taking to define the window period is crucial and repeat testing must be encouraged if the testing algorithm does not include 4th generation anti-HIV assay or NAAT.

Linkages to HIV confirmatory testing and antiretroviral therapy after online, supervised, HIV self-testing among Thai men who have sex with men and transgender women

INTRODUCTION

Online, supervised, HIV self-testing has potential to reach men who have sex with men (MSM) and transgender women (TGW) who never tested before and who had high HIV-positive yield. We studied linkages to HIV confirmatory test and antiretroviral therapy (ART) initiation among Thai MSM and TGW who chose online and/or offline platforms for HIV testing and factors associated with unsuccessful linkages.

METHODS

MSM and TGW were enrolled from Bangkok Metropolitan Region and Pattaya during December 2015 to June 2017 and followed for 12 months. Participants could choose between: 1) offline HIV counselling and testing (Offline group), 2) online pre-test counselling and offline HIV testing (Mixed group) and 3) online counselling and online, supervised, HIV self-testing (Online group). Sociodemographic data, risk behaviour and social network use characteristics were collected by self-administered questionnaires. Linkages to HIV confirmatory testing and/or ART initiation were collected from participants who tested reactive/positive at baseline and during study follow-up. Modified Poisson regression models identified covariates for poor retention and unsuccessful ART initiation.

RESULTS

Of 465 MSM and 99 TGW, 200 self-selected the Offline group, 156 the Mixed group and 208 the Online group. The Online group demonstrated highest HIV prevalence (15.0% vs. 13.0% vs. 3.4%) and high HIV incidence (5.1 vs. 8.3 vs. 3.2 per 100 person-years), compared to the Offline and Mixed groups. Among 60 baseline HIV positive and 18 seroconversion participants, successful ART initiation in the Online group (52.8%) was lower than the Offline (84.8%) and Mixed groups (77.8%). Factors associated with unsuccessful ART initiation included choosing to be in the Online group (aRR 3.94, 95% CI 1.07 to 14.52), <17 years old at first sex (aRR 3.02, 95% CI 1.15 to 7.92), amphetamine-type stimulants use in the past six months (aRR 3.6, 95% CI 1.22 to 10.64) and no/single sex partner (aRR 3.84, 95%CI 1.36 to 10.83) in the past six months.

CONCLUSIONS

Online, supervised, HIV self-testing allowed more MSM and TGW to know their HIV status. However, linkages to confirmatory test and ART initiation once tested HIV-reactive are key challenges. Alternative options to bring HIV test confirmation, prevention and ART services to these individuals after HIV self-testing are needed.

Risk Factors for Human Papillomavirus Infection and Abnormal Cervical Cytology Among Perinatally Human Immunodeficiency Virus-Infected and Uninfected Asian Youth

Background

Infection with high-risk human papillomavirus (HR-HPV) may be higher in perinatally human immunodeficiency virus (HIV)-infected (PHIV) than HIV-uninfected (HU) adolescents because of long-standing immune deficiency.

Methods

PHIV and HU females aged 12-24 years in Thailand and Vietnam were matched by age group and lifetime sexual partners. At enrollment, blood, cervical, vaginal, anal, and oral samples were obtained for HPV-related testing. The Wilcoxon and Fisher exact tests were used for univariate and logistic regression for multivariate analyses.

Results

Ninety-three PHIV and 99 HU adolescents (median age 19 [18-20] years) were enrolled (June 2013-July 2015). Among PHIV, 94% were currently receiving antiretroviral therapy, median CD4 count was 593 (392-808) cells/mm3, and 62% had a viral load <40 copies/mL. Across anogenital compartments, PHIV had higher rates of any HPV detected (80% vs 60%; P = .003) and any HR-HPV (60% vs 43%, P = .02). Higher proportions of PHIV had abnormal Pap smears (eg, atypical squamous cells of unknown significance [ASC-US], 12% vs 14%; low-grade squamous intraepithelial neoplastic lesions, 19% vs 1%). After adjusting for ever being pregnant and asymptomatic sexually transmitted infections (STI) at enrollment, PHIV were more likely to have HR-HPV than HU (odds ratio, 2.02; 95% confidence interval, 1.09-3.77; P = .03).

Conclusions

Perinatal HIV infection was associated with a higher risk of HR-HPV and abnormal cervical cytology. Our results underscore the need for HPV vaccination for PHIV adolescents and for prevention and screening programs for HPV and other STIs.

What would you choose: Online or Offline or Mixed services? Feasibility of online HIV counselling and testing among Thai men who have sex with men and transgender women and factors associated with service uptake

Introduction

HIV testing coverage remains low among men who have sex with men (MSM) and transgender women (TGW). We studied characteristics of Thai MSM and TGW who chose online and/or offline platforms for HIV counselling and testing and the feasibility of integrating online technologies and HIV self‐testing to create service options.

Methods

From December 2015 to June 2017, MSM and TGW enrolled from Bangkok Metropolitan Region and Pattaya could choose between: 1 offline HIV counselling and testing (Offline group), 2 online pre‐test counselling and offline HIV testing (Mixed group), and 3 online counselling and online, supervised, HIV self‐testing (Online group). Sociodemographic data, risk behaviour and social network use characteristics were collected by self‐administered questionnaires. Logistic regression models identified covariates for service preferences.

Results

Of 472 MSM and 99 TGW enrolled, 202 self‐selected the Offline group, 158 preferred the Mixed group, and 211 chose the Online group. The Online group had the highest proportion of first‐time testers (47.3% vs. 42.4% vs. 18.1%, p < 0.001) and reported highest HIV prevalence (15.9% vs. 13.0% vs. 3.4%, p = 0.001) as compared to Offline and Mixed groups, respectively. Having tested for HIV twice or more (OR 2.57, 95% CI 1.03 to 6.41, p = 0.04) increased the likelihood to choose online pre‐test counselling. Being TGW (OR 6.66, 95% CI 2.91 to 15.25, p < 0.001) and using social media from four to eight hours (OR 2.82, 95% CI 1.48 to 5.37, p = 0.002) or >8 hours (OR 2.33, 95% CI 1.05 to 5.16, p = 0.04) increased selection of online, supervised, HIV self‐testing. Providers primarily used smartphones (79.2%) and laptops (37.5%) to deliver online services. Self‐testing strip image sharpness and colour quality were rated “good” to “excellent” by all providers. Most participants (95.1%) agreed that online supervision and HIV self‐testing guidance offered were satisfactory and well delivered.

Conclusions

Online HIV services among MSM and TGW are feasible in Thailand and have the potential to engage high proportions of first‐time testers and those with high HIV prevalence. When designing public health interventions, integrating varied levels of online HIV services are vital to engage specific sections of MSM and TGW populations in HIV services.

Clinical Trial Number

NCT03203265

Drug-drug interactions between feminizing hormone therapy and pre-exposure prophylaxis among transgender women: the iFACT study

INTRODUCTION

Concerns over potential drug-drug interactions (DDI) between feminizing hormone therapy (FHT) and pre-exposure prophylaxis (PrEP) have hampered uptake and adherence of PrEP among transgender women (TGW). To determine DDI between FHT and PrEP, we measured the pharmacokinetic (PK) parameters of blood plasma estradiol (E2) and tenofovir (TFV) in Thai TGW.

METHODS

Twenty TGW who never underwent orchiectomy and had not received injectable FHT within six months were enrolled between January and March 2018. FHT (E2 valerate and cyproterone acetate) were prescribed to participants at baseline until week 5, and then from week 8 until the end of study. Daily PrEP (tenofovir disoproxil fumarate/emtricitabine) was initiated at week 3 and continued without interruption. Intensive E2 PK parameters and testosterone concentration at 24 hours (C24 ) were measured at weeks 3 (without PrEP) and 5 (with PrEP), and intensive TFV PK parameters were measured at weeks 5 (with FHT) and 8 (without FHT).

RESULTS

Median (interquartile range) age, body mass index, and creatinine clearance were 21.5 (21-26) years, 20.6 (19.0-22.4) kg/m2 , and 116 (101-126.5) mL/min, respectively. The geometric mean (%CV) of area under curve from time zero to 24 hours (AUC0-24 ), maximum concentration (Cmax ), and C24 of E2 at weeks 3 and 5 were 775.13 (26.2) pg h/mL, 51.47 (26.9) pg/mL, and 15.15 (42.0) pg/mL; and 782.84 (39.6), 55.76 (32.9), and 14.32 (67.4), respectively. The geometric mean (%CV) of TFV AUC0-24 , Cmax , and C24 at weeks 5 and 8 were 2242.1 (26.5) ng h/mL, 353.9 (34.0) ng/mL, and 40.9 (31.4) ng/mL; and 2530.2 (31.3), 311.4 (30.0), and 49.8 (29.6), respectively. The geometric mean of TFV AUC0-24 and C24 at week 5 were significantly less than that at week 8 by 12% (p = 0.03) and 18% (p < 0.001), respectively. There were no significant changes in E2 PK parameters and median C24 of bioavailable testosterone between week 3 and week 5.

CONCLUSIONS

Our study demonstrated lower blood plasma TFV exposure in the presence of FHT, suggesting that FHT may potentially affect PrEP efficacy among TGW; but E2 exposure was not affected by PrEP. Further studies are warranted to determine whether these reductions in TFV are clinically significant. Clinical Trial Number: NCT03620734.

Sexually transmitted infections and HIV RNA levels in blood and anogenital compartments among Thai men who have sex with men before and after antiretroviral therapy: implication for Treatment as Prevention programme

INTRODUCTION

Sexually transmitted infections (STIs) are common among HIV-positive men who have sex with men (MSM). There have been concerns that undiagnosed and untreated STIs could undermine efforts to use antiretroviral therapy (ART) for prevention due to genital secretion infectiousness. We evaluated the correlation between STIs and HIV RNA in anogenital compartments among HIV-positive MSM before and after ART.

METHODS

MSM participants newly diagnosed with HIV were offered ART regardless of CD4 count during November 2012 to November 2015. Syphilis serology, oropharyngeal swab, rectal swab, urine collection for gonorrhoea and chlamydia nucleic acid amplification testing, and HIV RNA measurement in blood, semen and rectal samples were performed at baseline, 12 and 24 months thereafter.

RESULTS

Of 143 HIV-positive MSM, 16.1% had syphilis, 23.1% had gonorrhoea and 32.8% had chlamydia at baseline. Participants with STIs at baseline had higher median HIV RNA levels in blood plasma (p = 0.053), seminal plasma (p = 0.01) and rectal secretions (p = 0.002) than those without STIs. Multivariate models identified HIV RNA 100,000 to 500,000 (OR 6.74, 95% CI 2.24 to 20.28, p = 0.001) and >500,000 (OR 9.39, 95% CI 1.08 to 81.72, p = 0.04) copies/mL in blood, CD4 count <350 cells/mm3 (OR 4.20, 95% CI 1.05 to 16.70, p = 0.04) and having any STIs (OR 2.62, 95% CI 1.01 to 6.80 p = 0.047) to be associated with detectable (>40 copies/mL) seminal plasma HIV RNA. Having chlamydia at any sites (OR 3.17, 95% CI 1.07 to 9.44, p = 0.04) was associated with detectable rectal HIV RNA. Incidences of syphilis, gonorrhoea and chlamydia were 13.4, 16.4 and 18.1 per 100 person-years respectively. Nine participants had detectable HIV RNA (five in blood, one in semen, two in rectal samples and one in both blood and rectal samples) at 12 and/or 24 months after ART.

CONCLUSIONS

STIs were extremely common among HIV-positive MSM prior to and after ART. ART effectively reduced HIV RNA in all compartments. The correlation between STIs and anogenital HIV RNA, especially prior to ART and likely until complete HIV RNA suppression from ART is achieved, points to the importance of integrating asymptomatic STIs screening into Treatment as Prevention programme for MSM.

Short Communication: Discordance in Drug Resistance Mutations Between Blood Plasma and Semen or Rectal Secretions Among Newly Diagnosed HIV-1-Infected Thai Men Who Have Sex with Men

Human immunodeficiency virus 1 (HIV-1) infection is most commonly transmitted by sexual contact across mucosal surfaces. Information on concordance in drug resistance profile between blood plasma and anogenital compartments in resource-limited settings is limited. We aimed to determine discordances in genotypic drug resistance-associated mutations (DRAMs) between blood plasma and semen or rectal secretions among newly diagnosed, antiretroviral therapy (ART)-naive, HIV-1-infected Thai men who have sex with men (MSM). Blood plasma, semen, and rectal secretions of HIV-1-infected Thai MSM enrolled from the Test and Treat cohort were tested for genotypic mutations in the reverse transcriptase and protease genes. Seven participants with baseline DRAMs in blood plasma were included in this analysis. In anogenital samples, HIV-1 RNA could be fully amplified for DRAMs assessment in semen from three participants and in rectal secretions from four participants. DRAMs were identified in semen from two of three participants and in rectal secretions from four of four participants. Three participants had DRAMs in anogenital compartments that were not detected in blood plasma-one had DRAMs in semen that was not detected in blood plasma (I54FI) and two had DRAMs in rectal secretions that was not detected in blood plasma (I47IM; K70N, L74I, Y115F, M184V, K103N, V108I, and H221Y). Discordance in DRAMs between blood plasma and anogenital compartments is not uncommon among newly diagnosed, ART-naive, HIV-1-infected Thai MSM. Monitoring of drug-resistant virus in these vector compartments is warranted particularly as pre-exposure prophylaxis and treatment as prevention are increasingly used as the mainstay strategies to end the AIDS epidemic.

Prevalence of and risk factors for anal high-risk HPV among HIV-negative and HIV-positive MSM and transgender women in three countries at South-East Asia

This study aimed to assess the prevalence of and associated risk factors for anal high-risk human papillomavirus (hr-HPV) infection among men who have sex with men (MSM) and transgender women (TGW) in Indonesia, Thailand, and Malaysia.This was baseline data from a prospective cohort study with clinic sites in Jakarta and Bali (Indonesia), Bangkok (Thailand), and Kuala Lumpur (Malaysia).MSM and TGW aged 18 years and older from Indonesia, Thailand, and Malaysia were enrolled. Demographic and behavioral characteristics were assessed, and anal samples were collected for HPV genotyping. Multivariate logistic regression models were used to assess risk factors for anal hr-HPV overall and among HIV-positive participants.A total of 392 participants were enrolled, and 48 were TGW. As many as 245 were HIV-positive, and 78.0% of the participants were on combination antiretroviral therapy (cART). Median CD4 count was 439 cells/mm and 68.2% had undetectable HIV-RNA. HIV-positive participants had significantly more hr-HPV compared to HIV-negative participants (76.6% vs 53.5%, P < .001). HPV-16 was the most common high-risk type (20%), whereas HPV-33, -39, and -58 were significantly more common among HIV-positive participants. HIV-positive participant significantly associated with anal hr-HPV infection compared with HIV-negative (OR: 2.87, 95% CI: 1.76-4.70, P ≤ .001), whereas among HIV-positive participants transgender identity had lower prevalence of hr-HPV infection (OR: 0.42, 95% CI: 0.19-0.91, P = .03).High-risk HPV infection was very common among MSM and TGW in South-East Asia. Overall, HIV-infection, regardless of cART use and immune status, significantly increased the risk, while among HIV-positive participants transgender identity seemed to decrease the risk of anal hr-HPV.

HIV rapid diagnostic testing by lay providers in a key population-led health service programme in Thailand

Introduction: Rapid diagnostic testing (RDT) for HIV has a quick turn-around time, which increases the proportion of people testing who receive their result. HIV RDT in Thailand has traditionally been performed only by medical technologists (MTs), which is a barrier to its being scaled up. We evaluated the performance of HIV RDT conducted by trained lay providers who were members of, or worked closely with, a group of men who have sex with men (MSM) and with transgender women (TG) communities, and compared it to tests conducted by MTs. Methods: Lay providers received a 3-day intensive training course on how to perform a finger-prick blood collection and an HIV RDT as part of the Key Population-led Health Services (KPLHS) programme among MSM and TG. All the samples were tested by lay providers using Alere Determine HIV 1/2. HIV-reactive samples were confirmed by DoubleCheckGold Ultra HIV 1&2 and SD Bioline HIV 1/2. All HIV-positive and 10% of HIV-negative samples were re-tested by MTs using Serodia HIV 1/2. Results: Of 1680 finger-prick blood samples collected and tested using HIV RDT by lay providers in six drop-in centres in Bangkok, Chiang Mai, Chonburi and Songkhla, 252 (15%) were HIV-positive. MTs re-tested these HIV-positive samples and 143 randomly selected HIV-negative samples with 100% concordant test results. Conclusion: Lay providers in Thailand can be trained and empowered to perform HIV RDT as they were found to achieve comparable results in sample testing with MTs. Based on the task-shifting concept, this rapid HIV testing performed by lay providers as part of the KPLHS programme has great potential to enhance HIV prevention and treatment programmes among key at-risk populations.

Low-level genital HIV shedding in Thai HIV-infected women with suppressed plasma viral load after menopause: a longitudinal study

OBJECTIVES

First, to evaluate the longitudinal changes of HIV RNA in genital secretions in HIV-positive women with plasma HIV RNA <50 copies/mL before and after the onset of menopause. Second, to assess inflammatory markers and prevalence of comorbidities after the onset of menopause.

METHODS

This was a prospective observational study with two time points. HIV RNA in genital secretions (GVL) was measured in 15 HIV-positive menopausal women (second time point). Results were compared to earlier available data for GVL from the same participant before the onset of menopause (first time point).

RESULTS

Median age at the first time point was 42 years, and 52 years at the second time point. Median time since the onset of menopause was 2 years and 33% of women were sexually active. Eighty per cent had at least one comorbidity. The GVL before menopause was >50 copies/mL in 27% of the participants, and in 40% after menopause. The GVL was <1000 copies/mL in all but one measurement. There was no significant difference between the two time points (P=0.687). Intermediate vaginal flora or bacterial vaginosis was found in 73% of participants during the second time point.

CONCLUSIONS

There was a high prevalence of low-level GVL shedding before and after menopause. This needs further investigation, especially in relation to the vaginal microbiome and the complex interactions between micro-organisms. HIV-infected women in menopause do not seem to present a major public health risk for HIV transmission. Nevertheless, safe sex should be discussed with all, regardless of age. The high prevalence of non-communicable diseases after menopause requires special attention and comprehensive care.

Human papillomavirus in anal biopsy tissues and liquid-based cytology samples of HIV-positive and HIV-negative Thai men who have sex with men

Background

Men who have sex with men (MSM) are at high risk of developing human papillomavirus (HPV)-related anal cancer. We compared HPV genotypes in anal tissues (Bx) and anal liquid-based cytology fluid (LBC) from HIV-positive and HIV-negative MSM.

Methods

Bx (32 normal, 41 low-grade squamous intraepithelial lesions (LSIL) and 22 high-grade squamous intraepithelial lesions (HSIL)), along with LBC from the same visit, were selected from 61 HIV-positive and 34 HIV-negative MSM who enrolled into a prospective cohort in Bangkok, Thailand. HPV genotyping was performed on Bx and LBC.

Results

Any HPV and high-risk HPV (HR-HPV) prevalence were 63.2% and 60.0% in Bx and 71.6% and 62.1% in LBC, respectively. HIV-positive MSM had higher rates of HR-HPV genotypes detection (70.5% vs. 47.1%, p=0.03) in LBC than HIV-negative MSM. HPV16 (27%) was the most common HR-HPV found in HSIL tissue. In HIV-positive MSM, the frequency of HR-HPV detection increased with histopathologic grading in both Bx and LBC samples. HSIL was associated with the presence of any HR-HPV(OR 7.6 (95%CI 1.8–31.9); P=0.006) in LBC and in Bx((OR 5.6 (95%CI 1.4–22.7); P=0.02).

Conclusions

Our data strongly support the integration of HR-HPV screening on LBC samples, along with HPV vaccination, into an anal cancer prevention program.

Low incidence of HIV infection in an anonymous HIV counselling and testing clinic cohort in Bangkok, Thailand despite high HIV prevalence and self-report of high-risk behaviour

BACKGROUND

HIV counselling and testing (HCT) clinics have the potential to be entry points for recruiting populations at high risk for HIV infection for HIV prevention and treatment studies. Cohort data from key populations are crucial for HIV study site selection.

METHOD

This cohort study recruited clients at an HCT clinic in Bangkok, Thailand. HIV prevalence was assessed along with demographics, perception of risk and behavioural risk factors. Participants who were HIV negative at baseline were followed up every 4 months for up to 1 year to measure HIV incidence and changes in risk behaviour.

RESULTS

A total of 992 subjects enrolled; median age was 30 years, 27% were men who have sex with men (MSM) and 8% were commercial sex workers (CSW). Baseline HIV prevalence was 10%. Factors positively associated with HIV infection were age >30 years, lower educational status and being MSM. Factors negatively associated with HIV infection were self-perception of minimal or moderate risk. Overall dropout rate was 49%, with 24% not returning after enrolment. HIV incidence was lower than expected at 0.50 per 100 person-years overall and 1.95 per 100 person-years for MSM.

CONCLUSIONS

This HCT population had a high baseline HIV prevalence but a low incidence rate on follow-up. Overall retention in the cohort was poor and may have resulted from suboptimal reminders and characteristics of high-risk clients who use anonymous HIV testing services. MSM had higher HIV incidence and better retention than other high-risk groups.

Cervical and anal HPV infection: cytological and histological abnormalities in HIV-infected women in Thailand

BACKGROUND

Women infected with human immunodeficiency virus (HIV) have higher rates of persistent infection with high-risk human papillomavirus (hr-HPV) and cervical and anal dysplasia. We describe the epidemiology of hr-HPV, and cervical and anal intra-epithelial abnormalities in HIV-infected women in Thailand.

METHODS

HIV-infected women aged 18-49 years, either HAART-naïve or -experienced, were enrolled in Bangkok, Thailand. A demographic and sexual-risk behaviour questionnaire was administered and a pelvic examination with colposcopy was performed on every woman. Cervical and anal samples were tested for cytology and HPV genotyping.

RESULTS

A total of 256 women were enrolled with a median [interquartile range (IQR)] age of 35 (32-40) years. Ninety (35.2%) had detectable cervical hr-HPV. Being post-menopausal was associated with increased risk for cervical hr-HPV, while years since HIV diagnosis and plasma HIV RNA <40 copies/mL were significantly associated with decreased risk in multivariable regression analyses. Abnormal cervical cytology was detected in 6.3%. Cervical biopsies that were taken from 99 women (39.3%) owing to abnormalities seen during colposcopy showed cervical intra-epithelial neoplasia (CIN) in 22.6%. The sensitivity of cervical cytology to detect CIN2+ was 10.0%. Among 102 women enrolled in the anal substudy, 18.8% had anal HPV infection and 11.1% had anal hr-HPV. Two women had abnormal anal cytology.

CONCLUSION

We found cervical and anal hr-HPV in 35.2% and 11.1% of Thai HIV-infected women, respectively. Moreover, the observed poor agreement between cervical cytology and histology results could indicate current cervical cancer screening programs for HIV-infected women might not be optimal for the detection of pre-neoplastic lesions.

Cervical cytological abnormalities and HPV infection in perinatally HIV-infected adolescents

BACKGROUND

Behaviourally HIV-infected adolescent females are at higher risk for abnormal cervical cytology and HPV infection compared to those who are uninfected, but data on perinatally HIV-infected adolescent females are lacking.

METHODS

Cervical cytology, HPV infection and E6/E7 mRNA were assessed in sexually active 12-24-year-old adolescent females: perinatally HIV-infected (group 1, n = 40), behaviourally HIV-infected (group 2, n = 10), and HIV-uninfected (group 3, n = 10).

RESULTS

Median age was lower in group 1 (18 years) than in groups 2 (24 years) and 3 (20.5 years) (P < 0.001), and median time since sexual debut was shorter: 2 vs 5 vs 4 years (P < 0.001). More trial participants in group 1 than group 2 were on antiretrovirals (90% vs 70%; P <0.001). Abnormal cervical cytology (atypical squamous cells of undetermined significance and higher) was observed in 30% (group 1), 40% (group 2) and 30% (group 3) (P = 0.92), whereas high-risk HPV infection was observed in 45%, 45% and 40%, respectively (P = 1.00). Positive E6/E7 mRNA was found in 28% of group 1, but not in other groups. High-risk HPV infection predicted abnormal cytology in all groups [OR 6.77, 95% confidence interval (CI) 1.99-23.0; P = 0.001). Additionally, plasma HIV RNA ≥50 copies/mL (OR 13.3, 95% CI 1.16-153.06; P = 0.04) predicted abnormal cytology in HIV-infected adolescent females.

CONCLUSIONS

Despite the younger age and shorter time since sexual debut, cervical cytological abnormalities and HPV infection were as common in perinatally HIV-infected as in behaviourally infected and uninfected adolescents. HPV vaccination, pre-cancer screening and antiretroviral treatment in HIV-infected female adolescents should be implemented to minimise the risk of cervical cancer.

A novel acute HIV infection staging system based on 4th generation immunoassay

BACKGROUND

Fourth generation (4thG) immunoassay (IA) is becoming the standard HIV screening method but was not available when the Fiebig acute HIV infection (AHI) staging system was proposed. Here we evaluated AHI staging based on a 4thG IA (4thG staging).

FINDINGS

Screening for AHI was performed in real-time by pooled nucleic acid testing (NAT, n=48,828 samples) and sequential enzyme immunoassay (EIA, n=3,939 samples) identifying 63 subjects with non-reactive 2nd generation EIA (Fiebig stages I (n=25), II (n=7), III (n=29), IV (n=2)). The majority of samples tested (n=53) were subtype CRF_01AE (77%). NAT+ subjects were re-staged into three 4thG stages: stage 1 (n=20; 4th gen EIA-, 3rd gen EIA-), stage 2 (n=12; 4th gen EIA+, 3rd gen EIA-), stage 3 (n=31; 4th gen EIA+, 3rd gen EIA+, Western blot-/indeterminate). 4thG staging distinguishes groups of AHI subjects by time since presumed HIV exposure, pattern of CD8+ T, B and natural killer cell absolute numbers, and HIV RNA and DNA levels. This staging system further stratified Fiebig I subjects: 18 subjects in 4thG stage 1 had lower HIV RNA and DNA levels than 7 subjects in 4thG stage 2.

CONCLUSIONS

Using 4th generation IA as part of AHI staging distinguishes groups of patients by time since exposure to HIV, lymphocyte numbers and HIV viral burden. It identifies two groups of Fiebig stage I subjects who display different levels of HIV RNA and DNA, which may have implication for HIV cure. 4th generation IA should be incorporated into AHI staging systems.

HIV type 1 molecular epidemiology among high-risk clients attending the Thai Red Cross Anonymous Clinic in Bangkok, Thailand

Several studies have reported an increasing number of non-CRF01_AE infections in high-risk groups in Thailand suggesting a more complex HIV-1 epidemic. This study assessed the complexity of the HIV epidemic among high-risk clients tested for HIV-1 at the Thai Red Cross Anonymous Clinic (TRCAC) between July 1, 2006 and February 28, 2007. HIV-1 genotypes were determined from plasma of infected subjects (n = 401) by the multiregion hybridization assay (MHAbce, v.2). Univariate and multivariate logistic regression analyses were used to determine risk factors associated with HIV prevalence and non-CRF01_AE infection. The estimated overall HIV prevalence was 14.1%: 25.3% among men who have sex with men (MSM), 18.4% among heterosexual women, and 9.6% among heterosexual men. Among the risk factors found to be associated with HIV prevalence were age (25-29 years), risk behavior (MSM), marital status (not single), education (less than high school), and inconsistent condom use. Overall, non-CRF01_AE strains accounted for 18.9% of the infections: 25.3% among MSM and 14.8% and 20.4% among heterosexual women and men, respectively. Our results indicate a concentrated and genetically complex HIV epidemic among Thai MSM. These findings advocate for targeted intervention and prevention measures among high-risk populations in Thailand.

HIV drug resistance transmission threshold survey in Bangkok, Thailand

Background

Antiretroviral therapy (ART) began in Thailand in the Bangkok Metropolitan Area (BMA) in 1988 and scale-up began in 2001. The national first-line regimen is stavudine, lamivudine and nevirapine in fixed-dose combination, which is a regimen with a low genetic barrier for resistance. Because viral load and resistance testing are not widely available, unidentified HIV drug resistance (HIVDR) may occur during treatment and could be transmitted.

Methods

We undertook a threshold survey to assess HIVDR transmission in two subsets of recently infected individuals in the BMA. The first group consisted of returning blood donors tested at the Thai Red Cross National Blood Centre who seroconverted within the past 12 months. The second group comprised recently infected (as defined by BED assay) clients of the Thai Red Cross voluntary counselling and testing centre (VCT).

Results

Genotyping of 50 consecutive specimens each from blood donors and VCT clients during 2005–2006 showed no mutations associated with HIVDR in the reverse transcriptase or protease regions of the HIV pol gene. These results are categorized by the WHO HIV drug resistance threshold survey method as representing a low prevalence (<5%) of transmitted HIV drug resistance.

Conclusions

Every effort should be made to minimize the emergence of resistance in treated individuals and to prevent primary and secondary HIV transmission. To continue to monitor HIVDR transmission, Thailand has planned additional surveys – including longitudinal surveys – in these and additional groups of individuals.

HIV drug resistance transmission threshold survey in Bangkok, Thailand

BACKGROUND

Antiretroviral therapy (ART) began in Thailand in the Bangkok Metropolitan Area (BMA) in 1988 and scale-up began in 2001. The national first-line regimen is stavudine, lamivudine and nevirapine in fixed-dose combination, which is a regimen with a low genetic barrier for resistance. Because viral load and resistance testing are not widely available, unidentified HIV drug resistance (HIVDR) may occur during treatment and could be transmitted.

METHODS

We undertook a threshold survey to assess HIVDR transmission in two subsets of recently infected individuals in the BMA. The first group consisted of returning blood donors tested at the Thai Red Cross National Blood Centre who seroconverted within the past 12 months. The second group comprised recently infected (as defined by BED assay) clients of the Thai Red Cross voluntary counselling and testing centre (VCT).

RESULTS

Genotyping of 50 consecutive specimens each from blood donors and VCT clients during 2005-2006 showed no mutations associated with HIVDR in the reverse transcriptase or protease regions of the HIV pol gene. These results are categorized by the WHO HIV drug resistance threshold survey method as representing a low prevalence (<5%) of transmitted HIV drug resistance.

CONCLUSIONS

Every effort should be made to minimize the emergence of resistance in treated individuals and to prevent primary and secondary HIV transmission. To continue to monitor HIVDR transmission, Thailand has planned additional surveys--including longitudinal surveys--in these and additional groups of individuals.