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August 2008 - present
Publications
Publications (224)
Background
Contraceptive use has complex effects on sexual behaviour and mood, including those related to reduced concerns about unintended pregnancy, direct hormonal effects and effects on endogenous sex hormones. We set out to obtain robust evidence on the relative effects of three contraceptive methods on sex behaviours, which is important for g...
Standard-of-care HIV pre-exposure prophylaxis (PrEP) is highly efficacious, but uptake of and persistence on a daily oral pill is low in many settings. Evaluation of alternate PrEP products will require innovation to avoid the unpractically large sample sizes in noninferiority trials. We propose estimating HIV incidence in people not on PrEP as an...
Introduction
South Africa has the highest national burden of HIV globally. Understanding drivers of HIV acquisition in recently completed, prospective studies in which HIV was an endpoint may help inform the strategy and investments in national HIV prevention efforts and guide the design of future HIV prevention trials. We assessed HIV incidence an...
Background
As oral pre-exposure prophylaxis (PrEP) becomes the standard of prevention globally, its potential effect on HIV incidence in clinical trials of new prevention interventions is unknown, particularly for trials among women. In a trial measuring HIV incidence in African women, oral PrEP was incorporated into the standard of prevention in t...
Introduction
HIV incidence estimates are important to characterize the status of an epidemic, identify locations and populations at high risk and to guide and evaluate HIV prevention interventions. We used the limiting antigen avidity assay (LAg) as part of a recent infection testing algorithm to estimate HIV incidence in the Akwa Ibom AIDS Indicat...
Development of safe and effective COVID-19 vaccines is a global priority and the best hope for ending the COVID-19 pandemic. Remarkably, in less than 1 year, vaccines have been developed and shown to be efficacious and are already being deployed worldwide. Yet, many challenges remain. Immune senescence and comorbidities in aging populations and imm...
Objectives
Reproductive aged women are at risk of pregnancy and sexually transmitted infections (STI). Understanding drivers of STI acquisition, including any association with widely used contraceptives, could help us to reduce STI prevalence and comorbidities. We compared the risk of STI among women randomised to three contraceptive methods.
Meth...
Key Messages
Essentially all HIV transmission is from people living with HIV (PLHIV) who do not know their infection status or have not yet achieved viral suppression, making support for these individuals and their risk contacts a priority for treatment and prevention efforts.
Proven approaches exist to reduce viral burden and interrupt HIV transmi...
We examined the consistency of national nutrition strategies and action plans (NNS) focusing on maternal, infant, and young child nutrition in Southeast Asia with regional and international recommendations. Between July and December 2017, we identified and extracted information on context, objectives, interventions, indicators, strategies, and coor...
Background:
Limited data exist on the effects of contraceptives on HIV disease progression. We studied the impact of DMPA-IM, the copper IUD and levonorgestrel (LNG) implant on HIV disease progression.
Methods:
We included women 16-35 years randomized to DMPA-IM, copper IUD, or levonorgestrel implant with incident HIV infection during the ECHO t...
Introduction
Global guidelines emphasize the ethical obligation of investigators to help participants in HIV‐endpoint trials reduce HIV risk by offering an optimal HIV prevention package. Oral pre‐exposure prophylaxis (PrEP) has increasingly become part of state‐of‐the‐art HIV prevention. Here we describe the process of integrating oral PrEP delive...
Background: Progress in gender equity can improve health at the individual and country levels.
Objectives: This study’s objective was to analyze recent trends in gender equity and identify historical and contextual factors that contributed to changes in gender equity in three countries: China, Nepal, and Nicaragua.
Methods: To assess gender equity...
Background:
Despite the recent increase in HIV infections among adolescents, little is known about their HIV knowledge and perceptions. This study, therefore, sought to examine the factors associated with comprehensive HIV knowledge, stigma, and HIV risk perceptions among young adolescents aged 10-14 years in Akwa Ibom State, Nigeria. Additionally...
Background:
Observational studies raise concern about a potential link between injectable progestin contraceptive use and HIV acquisition risk. This possible link is particularly relevant in sub-Saharan Africa where HIV risk is high and the method mix is skewed toward injectables. We developed the Planning for Outcomes (P4O) model (https://plannin...
Background:
Observational and laboratory studies suggest that some hormonal contraceptive methods, particularly intramuscular depot medroxyprogesterone acetate (DMPA-IM), might increase women's susceptibility to HIV acquisition. We aimed to compare DMPA-IM, a copper intrauterine device (IUD), and a levonorgestrel (LNG) implant among African women...
Background
Three consecutive prospective studies were conducted among people who inject drugs (PWID) from May 1995 through June 2012 in Bangkok, Thailand. We examined data from these studies to evaluate HIV incidence and explore trends in risk behaviours.
Methods
We used data from a 1995–1998 cohort study, a 1999–2004 HIV vaccine trial, and a 2005...
Table S1. Eight main use cases for HIV incidence assays (HIAs).
Table S2. Organization types and numbers of interviewees.
Table S3. Estimated costs of assay development from transfer to delivery by development phase.
Table S4. Cost Breakdown for Surveillance Surveys – Fixed versus Variable Costs by Type of Resource.
Table S5. Detailed Breakdown...
Introduction
Accurate incidence estimates are needed to characterize the HIV epidemic and guide prevention efforts. HIV Incidence assays are cost‐effective laboratory assays that provide incidence estimates from cross‐sectional surveys. We conducted a global market assessment of HIV incidence assays under three market scenarios and estimated the ec...
What is already known about this topic? Monitoring prevalence of advanced human immunodeficiency virus (HIV) disease (i.e., CD4+ T-cell count <200 cells/µL) among persons initiating antiretroviral therapy (ART) is important to help understand ART program outcomes, inform HIV prevention strategies, and forecast need for adjunctive therapies. What is...
Equitable access to antiretroviral therapy (ART) for men and women with human immunodeficiency virus (HIV) infection is a principle endorsed by most countries and funding bodies, including the U.S. President's Emergency Plan for AIDS (acquired immunodeficiency syndrome) Relief (PEPFAR) (1). To evaluate gender equity in ART access among adults (defi...
Although scale-up of antiretroviral therapy (ART) since 2005 has contributed to declines of about 30% in the global annual number of human immunodeficiency (HIV)-related deaths and declines in global HIV incidence, estimated annual HIV-related deaths among adolescents have increased by about 50% and estimated adolescent HIV incidence has been relat...
Women continue to be at special risk for HIV acquisition due to a complex mix of biological, behavioural, structural, cultural and social factors, with unacceptable rates of new infection. Scientific advances over the past decade have highlighted the use of antiretroviral (ARV) drugs as pre-exposure prophylaxis (PrEP) to prevent HIV acquisition (se...
Evaluation of differences between human immunodeficiency virus (HIV)-infected men and women in antiretroviral therapy (ART) enrollment characteristics and outcomes might identify opportunities to improve ART program patient outcomes and prevention impact. During September 2008-February 2012, retrospective cohort studies to estimate attrition of enr...
Preexposure prophylaxis with antiretroviral drugs has been effective in the prevention of human immunodeficiency virus (HIV) infection in some trials but not in others.
In this randomized, double-blind, placebo-controlled trial, we assigned 2120 HIV-negative women in Kenya, South Africa, and Tanzania to receive either a combination of tenofovir dis...
A promising development approach for addressing food and nutrition insecurity for orphans and vulnerable children (OVC) is permaculture. In the context of OVC programming permaculture helps guide communities toward permanent solutions for food and nutrition security while ensuring that these options exist harmoniously within their environment. The...
Project Accept is a community randomized, controlled trial to evaluate the efficacy of community mobilization, mobile testing, same-day results, and post-test support for the prevention of HIV infection in Thailand, Tanzania, Zimbabwe, and South Africa. We evaluated the accuracy of in-country HIV rapid testing and determined HIV prevalence in the P...
Background—Antiretroviral therapy that reduces viral replication could limit the transmission of human immunodeficiency virus type 1 (HIV-1) in serodiscordant couples.
An abstract is unavailable. This article is available as HTML full text and PDF.
In his News Focus story (“Treatment as prevention,” 5 March, p. [1196][1]), J. Cohen reviews ideas presented at the 17th Conference on Retroviruses and Opportunistic Infections about the use of HIV treatment as prevention. Enthusiasm for the treatment-as-prevention approach has grown in recent
More than half a million Americans became newly infected with human immunodeficiency virus (HIV) in the first decade of the new millennium. The domestic epidemic has had the heaviest impact on men who have sex with men and persons from racial and ethnic minority populations, particularly black persons. For example, black men who have sex with men r...
In April 2007, the Centers for Disease Control and Prevention (CDC) held a two-day consultation with a broad spectrum of stakeholders to obtain input on the potential role of male circumcision (MC) in preventing transmission of human immunodeficiency virus (HIV) in the U.S. Working groups summarized data and discussed issues about the use of MC for...
In April 2007, the Centers for Disease Control and Prevention (CDC) held a two-day consultation with a broad spectrum of stakeholders to obtain input on the potential role of male circumcision (MC) in preventing transmission of human immunodeficiency virus (HIV) in the U.S. Working groups summarized data and discussed issues about the use of MC for...
INTRODUCTION: HIV incidence is the rate of new infections in a population over time. HIV incidence is a critical indicator needed to assess the status and trends of the HIV epidemic in populations and guide and assess the impact of prevention interventions. METHODS: Several methods exist for estimating population-level HIV incidence: direct observa...
We investigated effects of vaccination with AIDSVAX B/E HIV-1 candidate vaccine on blood and seminal plasma HIV-1 RNA viral loads (BVL and SVL, respectively) in vaccine recipients (VRs) and placebo recipients (PRs) who acquired infection.
Linear mixed models were fitted for repeated measurements of BVL. Generalized estimating equations were used to...
To determine the status of the HIV epidemic in the United States and Canada.
We used data on AIDS and HIV diagnoses for 1996-2005 reported to the United States and Canadian national surveillance systems to determine trends in AIDS and HIV (33 US states only) diagnoses and to identify population groups most affected by HIV. HIV incidence for Canada...
BACKGROUND
Part of the explanation of why HIV and AIDS incidence rates have not declined in the last decade relates to patterns of HIV testing and knowledge of HIV serostatus. HIV testing is the gateway to medical treatment of HIV disease and for taking steps to protect one's sex and drug-using partners from exposure to HIV infection. Yet, undiagno...
4 Associate Director for Policy Planning and External Relations, Division of STD Prevention NCHSTP, CDC
Recent clinical trials in Africa found that male circumcision reduces the risk of acquiring HIV from heterosexual sex--what are the implications of these studies for the United States?
In northern Thailand, where substantial male-to-female transmission of HIV has occurred in stable partnerships, the relationships between counseling, communication, and HIV-preventive behaviors in married couples have not been well studied. In a study of HIV incidence among women in northern Thailand, each participant was advised to learn her husba...
This report summarizes the discussions and recommendations from a consultation held in New York City, USA (31 January-2 February 2006) organized by the joint World Health Organization-United Nations Programme on HIV/AIDS HIV Vaccine Initiative and the International AIDS Vaccine Initiative. The consultation discussed issues related to the design and...
To determine the safety and acceptability of vaginal application of Carraguard, a carrageenan-derived candidate microbicide gel.
A randomized, placebo-controlled, triple-blinded clinical trial was conducted in Chiang Rai, northern Thailand.
Women were asked to insert one applicator of study gel vaginally at least three times per week (with or witho...
Increased risk behavior among participants in HIV vaccine efficacy trials has been a concern. This study evaluated HIV sexual risk behavior among 5095 HIV-negative men who have sex with men (MSM) and 308 women enrolled in a randomized, double-blind, placebo-controlled efficacy trial of a bivalent rgp120 vaccine at 61 sites, primarily in North Ameri...
To estimate the frequency and incidence of dual HIV-1 subtype infections, including superinfections, among recent seroconvertors from a cohort of injection drug users (IDUs).
A total of 1209 HIV-negative IDUs were followed in a prospective cohort study at 15 methadone clinics in Bangkok, Thailand. After 2308 person-years (PY) of follow-up, 133 sero...
The leukocytes of rhesus monkeys contain cyclic octadecapeptides (theta;-defensins) that can protect cells from infection by HIV-1 in vitro. Although humans express mRNA from one or more theta;-defensin pseudogenes, these transcripts contain a premature stop codon that prevents formation of theta;-defensin peptides. We hypothesized that some highly...
The loss of viral control by the host may be due to the evolution of viruses with mutations that limit presentation by human leukocyte antigen (HLA) to cytotoxic T cells. The authors hypothesized that the consequence of such evolution might be that persons with common HLA class I alleles would be less able to control viremia, on average, than would...
Interventions to reduce sexual risk behavior among injecting drug users (IDUs) have generally had very modest effects, but almost all such interventions have been conducted within short time frames. This study assessed whether long-term participation in interventions to reduce sexual risk behavior was associated with reduced sexual risk behavior.
A...
Some candidate HIV-1 vaccines may not prevent HIV-1 infection but may alter the course of disease. Surrogate endpoints based on early laboratory makers in HIV-1-infected persons who are antiretroviral therapy (ART)-naive will be useful for evaluating vaccine efficacy in slowing disease progression (VEp). We examined pretreatment HIV-1 viral loads a...
Homo- or bisexual (HB) adolescents may have greater and different health risks than the population of heterosexual adolescents. We assessed sexual orientation and health risk behaviors in 1,725 consenting 15- to 21-year-old vocational school students in northern Thailand. Data were collected using audio-computer-assisted self-interviewing. Nine per...
To describe recruitment, screening and baseline characteristics of injection drug users (IDU) participating in a phase III HIV vaccine (AIDSVAX B/E; VaxGen, USA) trial and to compare enrollment characteristics between trial participants and 1209 IDU from a 1995-1998 vaccine trial preparatory cohort for changes that might impact trial design assumpt...
In 1990, a joint activity between the Thailand Ministry of Public Health (MoPH) and the U.S. Centers for Disease Control and Prevention (U.S. CDC) known as the “HIV/AIDS Collaboration” was born, its primary objective was to conduct HIV prevention research to contribute to HIV/AIDS control efforts in Thailand. The Collaboration maintained an office...
This chapter describes obstacles hindering the development of a preventive human immunodeficiency virus (HIV) vaccine, progress toward developing and evaluating vaccine candidates, clinical trials, the social and ethical issues involved in conducting HIV vaccine trials, and plans for future efficacy trials. Three obstacles are widely considered res...
Development of serologic tests to detect recent HIV-1 infection has generated worldwide interest in applying this approach to estimate incidence. We previously devised an IgG-capture BED-EIA (or BED-CEIA) that detects increasing levels of anti-HIV IgG following seroconversion to identify recent infection and to estimate incidence among persons infe...
Resistance to HIV-1 infection despite repeated exposures has been associated with one or more HIV-specific responses, enhanced nonspecific immune modifications, and/or host genetic polymorphisms in certain individuals (highly exposed, persistently seronegative, HEPS). In the present investigation, we focused on the CCR5 gene polymorphisms and the a...
The goals of this study were to identify and characterize recombinant human immunodeficiency virus type 1 (HIV-1) genomes among incident infections in a prospective cohort study of injecting drug users (IDUs) in Bangkok, Thailand. Through cross-sectional, comparative phylogenetic analysis of the protease and env (C2-V4) gene regions, subtype discor...
To investigate knowledge and perceptions of HIV transmission risk and interest in vaginal microbicides in northern Thailand, we conducted 14 focus group discussions and 80 interviews with men and women in Chiang Rai province. Women were recruited from antenatal or postpartum clinics, and men from various work sites. Participants evinced substantial...
The performance of the bioMérieux Vironostika-LS EIA (less sensitive enzyme immunoassay) was assessed to detect recent seroconversion among injecting drug users (IDUs) in Bangkok, Thailand who were infected with either HIV-1 subtypes B' or E (also known as circulating recombinant form CRF01_AE). To evaluate the Vironostika-LS EIA in non-B subtypes,...
To determine changes in risk behavior in relation to study participation among injecting drug users (IDUs) in Bangkok, Thailand.
During 1995-1996, 1,209 HIV-seronegative IDUs were recruited from Bangkok Metropolitan Administration drug abuse treatment programs to participate in a prospective cohort study. Study visits occurred every 4 months, at wh...
Previous studies of sexual behavior and sexually transmitted diseases (STDs) in Thai adolescents may have been limited by participation bias and underreporting of stigmatized behaviors.
The goal was to increase knowledge about risk behaviors and STDs among youths in Thailand.
Students aged 15 to 21 years completed an audio-computer-assisted self-in...
A safe, effective, and affordable vaccine remains the best long-term hope for bringing the global human immunodeficiency virus/acquired
immunodeficiency syndrome (HIV/AIDS) epidemic under control. Recent scientific developments have suggested that the first
generation of HIV vaccines available for public health care use will likely be of low to mod...
Factors facilitating or inhibiting women's ability to leave sex work are still poorly characterized, and little is known about women's lives after they leave the profession. This paper presents findings from a qualitative study about factors affecting women's ability to leave sex work and influencing their lives after leaving. We interviewed 42 cur...
A provincial referral hospital in northern Thailand, where a cross-sectional study during 1995-1996 reported on the occupational risk of Mycobacterium tuberculosis transmission.
To describe the effectiveness of prevention strategies for nosocomial tuberculosis (TB).
A prospective study among health care workers (HCW) including annual tuberculin ski...
A provincial referral hospital in northern Thailand, where a cross-sectional study from 1995-1996 reported on the occupational risk of Mycobacterium tuberculosis transmission.
To assess the impact of acid-fast bacilli sputum smear-positive results notification to improve tuberculosis (TB) services by documenting the location of sputum collection, c...
Delineating factors associated with extrapulmonary cryptococcosis (EPC), a major disease burden among Thailand's AIDS patients, can clarify its pathogenesis and guide preventive interventions. From November 1993 through June 1996, enhanced surveillance of 2261 human immunodeficiency virus (HIV)-seropositive patients in a hospital near Bangkok showe...
This chapter emphasizes the global molecular epidemiology of human immunodeficiency virus (HIV) including an overview of its genetic diversity and related implications. Advances in molecular biology, immunology, and epidemiology have contributed greatly to the understanding of HIV. HIV is a primate retrovirus that shares the ability to infect their...
To describe survival and signs of human immunodeficiency virus (HIV) infection in perinatally infected children in Thailand.
At 2 large Bangkok hospitals, 295 infants born to HIV-infected mothers were enrolled at birth from November 1992 through September 1994 and followed up with clinical and laboratory evaluations every 1 to 3 months for 18 month...
Data from drug treatment facilities, drug seizures and drug arrests suggest rapidly increasing methamphetamine use by adolescents in Thailand. However, limited quantitative data are available about the prevalence of its use or correlates of use. The purpose of our study was therefore to estimate the prevalence of methamphetamine use and to identify...
In this study, we describe two cases of human immunodeficiency virus type 1 (HIV-1) intersubtype superinfection with CRF01_AE
and subtype B strains, which occurred in two injection drug users participating in a prospective cohort study in Bangkok,
Thailand. In both cases, the superinfecting strain was detected by molecular and serologic analyses se...
Increased support from the global HIV/AIDS community is driving advances in HIV treatment and vaccine development in the developing world. Care of patients with AIDS includes many biomedical, nutritional, psychosocial, and behavioural interventions. In resource-poor settings, antiretroviral drugs should be given with use of standardised treatment r...
We analyzed data from a prospective cohort study of injection drug users (IDUs) attending methadone treatment clinics in Bangkok, Thailand, during 1995-1998 to characterize factors associated with a period of high incidence (PHI) from July 1996 through January 1997 compared with periods of lower incidence. Sociobehavioral characteristics were simil...
During 1995-1996, 1,209 HIV-1-negative injection drug users (IDUs) attending methadone treatment clinics operated by the Bangkok Metropolitan Administration in Bangkok, Thailand, were enrolled in a prospective cohort study. Through 1998, 133 of these IDUs had seroconverted to HIV-1; 130 of these seroconverters were included in this study. HIV-1 CRF...
We analyzed data from a prospective cohort study of injection drug users (IDUs) attending methadone treatment clinics in Bangkok, Thailand, during 1995-1998 to characterize factors associated with a period of high incidence (PHI) from July 1996 through January 1997 compared with periods of lower incidence. Sociobehavioral characteristics were simil...
Objective: To examine the long-term structure of the high human immunodeficiency virus (HIV) prevalence epidemic among injecting drug users (IDUs) in Bangkok, Thailand. Methods: Annual HIV seroprevalence surveys were conducted at the drug abuse treatment clinics of the Bangkok Metropolitan Administration (BMA) from 1987 onward. Risk behavior survey...
To determine the incidence of and risk factors for HIV-1 infection among married women in northern Thailand, we enrolled 779 seronegative women from family planning clinics and a postpartum ward in Chiang Rai, Thailand, from 1998 through 1999. Women were tested for HIV antibodies at 6 and 12 months after enrollment. They received HIV prevention cou...
We have devised a simple enzyme immunoassay (EIA) that detects increasing levels of anti-HIV IgG after seroconversion and can be used for detecting recent HIV-1 infection. Use of a branched peptide that included gp41 immunodominant sequences from HIV-1 subtypes B, E, and D allowed similar detection of HIV-specific antibodies among various subtypes....
To determine the incidence of and risk factors for HIV-1 infection among married women in northern Thailand, we enrolled 779 seronegative women from family planning clinics and a postpartum ward in Chiang Rai, Thailand, from 1998 through 1999. Women were tested for HIV antibodies at 6 and 12 months after enrollment. They received HIV prevention cou...
The Bangkok (Thailand) Metropolitan Administration cohort of injecting drug users (IDUs) consisted of 1,209 IDUs initially seronegative for human immunodeficiency virus (HIV) who were followed from 1995 to 1998 at 15 Administration drug treatment clinics. At enrollment and approximately every 4 months thereafter, participants were assessed for HIV...
