Factors associated with testing for HIV and other sexually transmitted infections in men who have sex with men and transgender women in Bangkok, Thailand.

BACKGROUND: Routine screening for HIV and other sexually transmitted infections (STIs) facilitates early diagnosis and treatment, thereby preventing morbidity and onward transmission. We estimated the prevalence of prior HIV/STI testing among men who have sex with men (MSM) and transgender women (TGW) in Bangkok, Thailand, and identified factors associated with prior testing. METHODS: Cross-sectional analyses were performed using data collected at enrollment into an HIV incidence cohort. From April to October 2017, MSM and TGW were enrolled if they were aged 18-35 years, reported anal intercourse with a male or TGW partner, and reported behavioral vulnerability to HIV. Participants answered questions about demographics, sexual behaviors, and lifetime HIV/STI testing history. Multivariable robust Poisson regression was used to estimate risk ratios (RRs) and 95% confidence intervals (CIs) for factors potentially associated with prior testing. RESULTS: Among 1,014 participants, 348 (34.3%) were TGW and the median age was 21.6 (interquartile range 20.0-24.8) years. Prior testing for HIV was reported by 421 (41.5%) and for other STIs by 268 (26.4%). HIV testing was more common among participants aged ≥ 22 years (RR 1.37 [95% CI 1.13-1.67]), with college education as compared to secondary or less (RR 1.37 [95% CI 1.08-1.72]), and who met male sexual partners online (RR 1.52 [95% CI 1.24-1.85]), but lower among participants attracted to both men and women as compared to men only (RR 0.64 [95% CI 0.51-0.81]) and who met male sexual partners in bars (RR 0.83 [95% CI 0.72-0.97]). Similar associations were observed with prior testing for other STIs, including increased testing among participants with college education (RR 1.52 [95% CI 1.11-2.09]) and who met male sexual partners online (RR 1.73 [95% CI 1.30-2.31]), but lower among participants attracted to both men and women (RR 0.70 [95% CI 0.51-0.96]) and who met male sexual partners in bars (RR 0.67 [95% CI 0.54-0.83]). CONCLUSIONS: Despite behavioral vulnerability, prior testing for HIV and other STIs was uncommon. Online engagement strategies may be effectively reaching Thai MSM and TGW who meet sexual partners online, but new interventions are needed to encourage testing among younger, less educated, and bisexual MSM and TGW.

Ex vivo piperaquine resistance developed rapidly in Plasmodium falciparum isolates in northern Cambodia compared to Thailand.

BACKGROUND: The recent dramatic decline in dihydroartemisinin-piperaquine (DHA-PPQ) efficacy in northwestern Cambodia has raised concerns about the rapid spread of piperaquine resistance just as DHA-PPQ is being introduced as first-line therapy in neighbouring countries. METHODS: Ex vivo parasite susceptibilities were tracked to determine the rate of progression of DHA, PPQ and mefloquine (MQ) resistance from sentinel sites on the Thai-Cambodian and Thai-Myanmar borders from 2010 to 2015. Immediate ex vivo (IEV) histidine-rich protein 2 (HRP-2) assays were used on fresh patient Plasmodium falciparum isolates to determine drug susceptibility profiles. RESULTS: IEV HRP-2 assays detected the precipitous emergence of PPQ resistance in Cambodia beginning in 2013 when 40 % of isolates had an IC90 greater than the upper limit of prior years, and this rate doubled to 80 % by 2015. In contrast, Thai-Myanmar isolates from 2013 to 14 remained PPQ-sensitive, while northeastern Thai isolates appeared to have an intermediate resistance profile. The opposite trend was observed for MQ where Cambodian isolates appeared to have a modest increase in overall sensitivity during the same period, with IC50 declining to median levels comparable to those found in Thailand. A significant association between increased PPQ IC50 and IC90 among Cambodian isolates with DHA-PPQ treatment failure was observed. Nearly all Cambodian and Thai isolates were deemed artemisinin resistant with a >1 % survival rate for DHA in the ring-stage assay (RSA), though there was no correlation among isolates to indicate cross-resistance between PPQ and artemisinins. CONCLUSIONS: Clinical DHA-PPQ failures appear to be associated with declines in the long-acting partner drug PPQ, though sensitivity appears to remain largely intact for now in western Thailand. Rapid progression of PPQ resistance associated with DHA-PPQ treatment failures in northern Cambodia limits drugs of choice in this region, and urgently requires alternative therapy. The temporary re-introduction of artesunate AS-MQ is the current response to PPQ resistance in this area, due to inverse MQ and PPQ resistance patterns. This will require careful monitoring for re-emergence of MQ resistance, and possible simultaneous resistance to all three drugs (AS, MQ and PPQ).

Pork consumption and seroprevalence of hepatitis E virus,Thailand, 2007-2008.

The nationwide seroprevalence of hepatitis E IgG was determined among young men in Thailand. Overall seroprevalence was 14% (95% CI 13%-15%); range by province was 3%-26%. Seroprevalence was lowest in the south, an area predominantly occupied by persons of the Islam religion, whose dietary laws proscribe pork.

Scrub typhus outbreak, northern Thailand, 2006-2007.

During a scrub typhus outbreak investigation in Thailand, 4 isolates of O. tsutsugamushi were obtained and established in culture. Phylogenetic analysis based on the 56-kDa type-specific antigen gene demonstrated that the isolates fell into 4 genetic clusters, 3 of which had been previously reported and 1 that represents a new genotype.

Cytokine profiles in HIV-1 subtype CRF01_AE infected individuals with different rates of diseases progression: a multiplex immunoassay.

OBJECTIVE: Cytokines play an important role in controlling the homeostasis of the immune system and contribute to the pathogenesis of HIV infection. The measurement soluble cytokines in plasma of HIV-1 infected individuals with different rates of disease progression may provide additional information to complement prognostic markers and understand disease process. The aim of the present study was to determine the cytokine profiles in plasma of Thai HIV-1 CRFO1_AE infected individuals with different rates of disease progression by using a multiplex system for simultaneous detection of 7 cytokines. MATERIAL AND METHOD: The authors used a multiplex immunoassay method to measure 7 cytokines (IL-2, IL-4, IL-6, IL-7, IL-10, IL-15 and IFN-gamma) in plasma of 23 progressors (PRs; symptomatic or AIDS within 5 years and CD4+ < 200/mm3), 23 slower progressors (SPs; asymptomatic more than 5 years and CD4+ > 350/mm3) and 23 normal healthy individuals. RESULTS: Both PRs and SPs demonstrated significantly higher levels of IL-7, IL-10 and IFN-gamma than healthy controls (p < 0.05). No significant difference in IL-6 between SPs and healthy controls but significant difference between RPs and controls were found. Furthermore, PRs showed significantly higher levels of plasma IL-6 (p = 0.001), IL-7 (p = 0.016), IL-10 (p < 0.001) and IFN-gamma (p = 0.026) than SPs. No significant difference in IL-2, IL-4 and IL-15 was found among 3 groups (PRs, SPs and healthy control). CONCLUSION: These results suggested that a Th1 to Th2 cytokine switch did not occur. However, the measurements of plasma levels of cytokines could be used for predicting disease progression.

Plasmodium falciparum phenotypic and genotypic resistance profile during the emergence of Piperaquine resistance in Northeastern Thailand.

Malaria remains a public health problem in Thailand, especially along its borders where highly mobile populations can contribute to persistent transmission. This study aimed to determine resistant genotypes and phenotypes of 112 Plasmodium falciparum isolates from patients along the Thai-Cambodia border during 2013-2015. The majority of parasites harbored a pfmdr1-Y184F mutation. A single pfmdr1 copy number had CVIET haplotype of amino acids 72-76 of pfcrt and no pfcytb mutations. All isolates had a single pfk13 point mutation (R539T, R539I, or C580Y), and increased % survival in the ring-stage survival assay (except for R539I). Multiple copies of pfpm2 and pfcrt-F145I were detected in 2014 (12.8%) and increased to 30.4% in 2015. Parasites containing either multiple pfpm2 copies with and without pfcrt-F145I or a single pfpm2 copy with pfcrt-F145I exhibited elevated IC90 values of piperaquine. Collectively, the emergence of these resistance patterns in Thailand near Cambodia border mirrored the reports of dihydroartemisinin-piperaquine treatment failures in the adjacent province of Cambodia, Oddar Meanchey, suggesting a migration of parasites across the border. As malaria elimination efforts ramp up in Southeast Asia, host nations militaries and other groups in border regions need to coordinate the proposed interventions.

A whole blood lymphocyte proliferation assay in healthy Thais: comparison of heparinized blood and acid citrate dextrose blood.

The lymphocyte proliferation assay (LPA) is a technique to determine T-lymphocyte functions in vitro. The standard LPA using peripheral blood mononuclear cells (PBMC) separated from heparinized blood requires a large blood sample, time consuming and expensive. It is more useful if acid citrate dextrose (ACD) blood could be used not only for LPA but also for other purposes. To determine whether whole blood composing between heparinized blood and ACD blood could be substituted for standard LPA using PBMC. Heparinized and ACD blood of 35 healthy Thai blood donors were studied herein. PBMC separated by density gradient centrifugation and diluted heparinized and ACD blood were used to test and compare for lymphoproliferative responses to phytohemagglutinin (PHA), pokeweed mitogen (PWM), and tetanus toxoid. A stimulation index (SI) for each mitogen or antigen was calculated. All Thai blood donors demonstrated positive proliferative responses to PHA and PWM by using PBMC and whole blood culture assays from both heparinized and ACD blood. However, the difference in the frequency of positive proliferative responses to tetanus toxoid by using PBMC and whole blood culture assays was significant. Nevertheless, no significant difference in frequency of positive responses to tetanus toxoid between heparinized and ACD blood was observed. This results suggested that no significant difference between using heparinized and ACD blood in standard LPA using PBMC. However, the whole blood LPA for measuring mitogen induced lymphoproliferation could be substituted for standard LPA from heparinized andACD blood. Whole blood LPA is easy, rapid, and more cost effective than PBMC culture assay. Thus, it would be applicable in a clinical laboratory as well as in research setting.

HIV-1 incidence estimates among young Thai men using IgG-capture BED-enzyme immunoassay (BED-CEIA) during 2005-2006.

BACKGROUND: Knowledge about the most recent HIV epidemic among young generation in Thailand is crucial for improving the prevention programs. It is important to distinguish between recent and long-term HIV-1 infections among the sero-surveillance populations to estimate the HIV-1 incidence. OBJECTIVE: To obtain the HIV-1 incidence estimates in young Thai men from the HIV-1 sero-surveillance among the Royal Thai Army (RTA) conscripts inducted between November 2005 and November 2006. MATERIAL AND METHOD: The confirmed HIV-1 positive serum samples obtained from the November 2005, May 2006, and November 2006 rounds of RTA conscripts induction were selected to be included in the study. The recent HIV-1 infections were detected among the confirmed HIV-1 positive serum samples using an HIV-1 BED incidence EIA Kit (Calypte HIV-1 BED Incidence EIA, Calypte Biomedical Corporation, Maryland, USA. The incidence estimates were obtained in each round of the induction using a consensus formula was agreed upon at the US Centers for Disease Controls and Preventions (CDC). RESULTS: Eighty seven thousand one hundred seventy eight RTA conscripts were tested for HIV-1 infection between November 2005 and November 2006. The prevalence of HIV-1 infection was 0.51%, 0.60%, and 0.50% for the period of November 2005, May 2006, and November 2006, respectively. The HIV-1 incidence estimates were 0.14%/year (95% CI, 0.09-0.20), 0.20% year (95% CI, 0.13-0.28), and 0.17%/year (95% CI, 0.10-0.29) in November 2005, May 2006, and November 2006, respectively. CONCLUSION: We reported the HIV-1 incidence estimates obtained from the IgG-capture BED-enzyme immunoassay (BED-CEIA) method in the RTA conscripts sero-surveillance population. The incidence estimates were ranging from 0.14% - 0.20%/year between November 2005 and November 2006. The estimates could serve as the recent baseline information for future HIV prevention interventions in Thailand.

Hepatitis E virus infection in Thai troops deployed with U.N. peacekeeping forces.

The hepatitis E virus (HEV) is thought to be endemic throughout much of the world, particularly where sanitary infrastructure remains inadequate. HEV has been considered a military health threat and has been reported in several military environments. This study determined HEV seroconversion (defined by a 4-fold increase in antibody titers) occurring in Thai soldiers deployed to the HEV-endemic areas of East Timor, Afghanistan, and Iraq, as part of the U. N. multinational forces. With an average deployment of 6.4 months, the annualized seroconversion rates after deployments to East Timor, Afghanistan, Burundi, and Iraq were 1.9%, 4.6%, 4.6%, and 3.9%, respectively.

The importance of militaries from developing countries in global infectious disease surveillance.

Military forces from developing countries have become increasingly important as facilitators of their government's foreign policy, taking part in peacekeeping operations, military exercises and humanitarian relief missions. Deployment of these forces presents both challenges and opportunities for infectious disease surveillance and control. Troop movements may cause or extend epidemics by introducing novel agents to susceptible populations. Conversely, military units with disease surveillance and response capabilities can extend those capabilities to civilian populations not served by civilian public health programmes, such as those in remote or post-disaster settings. In Peru and Thailand, military health organizations in partnership with the military of the United States use their laboratory, epidemiological, communications and logistical resources to support civilian ministry of health efforts. As their role in international affairs expands, surveillance capabilities of militaries from developing countries should be enhanced, perhaps through partnerships with militaries from high-income countries. Military-to-military and military-to-civilian partnerships, with the support of national and international civilian health organizations, could also greatly strengthen global infectious disease surveillance, particularly in remote and post-disaster areas where military forces are present.

Molecular epidemiology of HIV Type 1 in preparation for a Phase III prime-boost vaccine trial in Thailand and a new approach to HIV Type 1 genotyping.

To characterize HIV-1 genotypes in candidate populations for a prime-boost phase III vaccine trial in Thailand, specimens from prevalent and incident HIV-1 infections from a family planning clinic population in Rayong Province and a community cohort in Chon Buri Province, collected from 1998 to 2001, were genotyped. A new multiregion hybridization assay, MHAbce, capable of distinguishing HIV-1 CRF01_AE, subtype B, and subtype C and their recombinants, was developed and applied to prevalent infections. Most incident and selected prevalent infections were studied by complete genome sequencing. By MHAbce, 168 of 194 prevalent infections were genotyped. Of these, 90.5% were CRF01_AE, 2.4% were subtype B, and 7.2% showed discordant or dual probe reactivity, indicative of recombination or dual infection, respectively. Among 23 incident infections, 20 were sequenced. Eighteen CRF01_AE, one subtype B, and one CRF01/B recombinant strains were seen. Two CRF01/B and one CRF01/C recombinant were identified among selected prevalent infections. These results indicate that incident and prevalent HIV-1 infections in Rayong and Chon Buri during 1998-2001 were 90% CRF01_AE, 3% subtype B, and 7% either recombinant or dual. This study frames the genetic diversity of HIV-1 in these cohorts in their preparatory phase for the ongoing ALVACHIV (vCP1521) prime, AIDSVAX B/E boost, phase III vaccine trial and will provide a benchmark for interpretation and analysis.

HLA Class I Alleles Associated with Mortality in Thai Military Recruits with HIV-1 CRF01_AE Infection.

In HIV-1-infected patients, variation at the HLA class I locus is associated with disease progression, but few studies have assessed the influence of HLA alleles on HIV-1 CRF01_AE infection, which is dominant in Thailand. We hypothesized that alleles predicted to confer more effective immune responses, such as HLA-B*46, would protect against disease progression. HLA typing was performed on HIV-1 incident cases surviving until 1998-1999 and HIV-1-negative matched controls from Thai army cohorts enrolled between 1991 and 1995. We assessed associations between class I alleles and disease progression subsequent to HLA typing. Ninety-nine HIV-1-incident cases were followed for a median of 3.7 years after HLA typing; during this time, 58 participants died. Two alleles were associated with mortality: HLA B*51 was protective (3-year survival B*51(pos) vs. B*51(neg): 75% vs. 52%; p = 0.034) whereas Cw*04 was deleterious (3-year survival Cw*04(pos) vs. Cw*04(neg): 39% vs. 60%; p = 0.027). HLA-B*46 was not associated with disease progression. Alleles present at different frequencies in HIV-1-incident compared with HIV-1-negative men included HLA-A*02:03, B*35, B*15, and C*08. 1. In conclusion in this Thai army cohort, HLA-B*51 was associated with lower mortality, confirming that this allele, which is protective in clade B HIV-1 infection, has a similar effect on HIV CRF01_AE infection. The deleterious effect of HLA-Cw*04 must be interpreted with caution because it may be in linkage disequilibrium with disease-susceptible HLA-B alleles. We did not find that HLA-B*46 was protective. These findings may inform vaccine development for areas of the world in which HIV-1 CRF01_AE infection is prevalent.

The development of HIV research laboratories in the Royal Thai Army Medical Department.

The development of HIV research laboratories at the Armed Forces Research Institute of Medical Sciences (AFRIMS), Royal Thai Army Medical Department in supporting of HIV-1 vaccine trials in Thailand was implemented in 1991. The collaboration between AFRIMS, Royal Thai Army Medical Department, and the US Military HIV Research Program with the ultimate goal to conduct the HIV-1 vaccine trial phase III. The HIV serology lab was set up for surveillance program in military recruits. Then, there was a need to strengthen more on the existing laboratories by training personnel to cope with the confidentiality of the lab results, specimen processing and data management which are critical. Later on, the necessary laboratory for measuring of vaccine immunogenicity was developed, such as lymphoproliferation assay. Additionally, a molecular biology lab was also developed. The HIV research laboratory management must include an ability to deal with some problems, such as late specimen receiving, fluctuating of power supply, technical staffs maintained. Good laboratory practices and safety must be strictly implemented. Communication network among facilities also played an important role in HIV laboratory strengthening at AFRIMS.

Dot-ELISA Rapid Test Using Recombinant 56-kDa Protein Antigens for Serodiagnosis of Scrub Typhus.

We developed a rapid dot-enzyme-linked immunosorbent assay (dot-ELISA) using the combination of recombinant 56-kDa protein antigens that exhibited broad reactivity with serum antibodies against the four most prevalent strains (Karp, Kato, Gilliam, and TA763) of Orientia tsutsugamushi. The assay is rapid (30 minutes), and can be done at room temperature, and results can be read by the naked eye. Only a simple shaker is required to wash the membrane. Sera from 338 patients suspected of being ill with scrub typhus from rural hospitals around Thailand were tested using this dot-ELISA. Seventy-five (22.2%) patients were found to be positive. The sensitivity and specificity of dot-ELISA were determined using the indirect immunofluorescent assay (IFA) test as the gold standard, with the cutoff titer of immunoglobulin peroxidase conjugate M (IgM)/G (IgG) greater than 1:400/1:400. The dot-ELISA had a sensitivity of 98.5%, a specificity of 96.3%, a positive predictive value of 86.7%, and a negative predictive value of 99.6% for the acute-phase specimens. The results indicate that dot-ELISA rapid test using recombinant 56-kDa protein antigen was comparable with the IFA test and may be very useful for the diagnosis of scrub typhus in rural hospitals, where IFA is not available.

The association between hepatitis C virus and HIV-1 in preparatory cohorts for HIV vaccine trials in Thailand.

OBJECTIVES: To study the association between hepatitis C virus (HCV) and HIV-1, and HCV seropositivity as an indicator of HIV-1 risk behavior for HIV vaccine preparatory cohorts in Thailand. DESIGN: Cross-sectional study of HIV-1-infected persons identified at screening for potential HIV vaccine trial cohort studies. METHODS: Sera from HIV-1-infected and uninfected volunteers was matched by age, sex, and community, and tested for HCV reactivity. Logistic regression methods were used to measure associations between HIV-1, HCV and other risk factors for HIV infection. RESULTS: The prevalence of HCV among HIV-negative controls was 8.3% (6/72) for men and 4.2% (5/118) for women. Co-infection with HIV and occurred in 50.7% (37/73) of men and 3.4% (4/118) of women. Among men who reported injection drug use (IDU), 96.4% (27/28) were HCV seropositive. No women reported IDU. HCV was associated with HIV infection [odds ratio (OR), 11.3; 95% confidence interval (CI), 4.4-29.3] and IDU (OR, 12.0; 95% CI, 3.4-41.9) among men, but not women (OR, 0.8; 95% CI, 0.2-3.0). After adjustment for potential confounding, HCV, but not IDU, remained strongly associated with HIV-1 infection among men (OR, 9.4; 95% CI, 2.7-32.6). CONCLUSIONS: The strong associations between HCV seropositivity, HIV-1 infection, and IDU history suggest that IDU was reported accurately in this study. The surprisingly high prevalence of HCV among HIV-1-infected young men may assist health policy makers in the choice of behavioral interventions for this important subgroup of the population.

A new circulating recombinant form, CRF15_01B, reinforces the linkage between IDU and heterosexual epidemics in Thailand.

HIV-1 subtype B and CRF01_AE have been in circulation in Thailand and Southeast Asia for more than a decade. Initially separated by risk group, the two strains are increasingly intermixed, and two recombinant strains of essentially reciprocal structure have been recently reported. Here we identify additional CRF_01B recombinants and provide the evidence that HIV-1 strains now pass freely between the two high-risk populations. HIV isolates that showed discordance between CRF01_AE and subtype B in multi-region genotyping assays were selected for the study. They were drawn from 3 different cohorts in Thailand representing different risk behaviors and demographic characteristics: a drug user cohort in the north, a family planning clinic attendee cohort in the southeast, and a cohort study of the mucosal virology and immunology of HIV-1 infection in Thailand. The DNA from these isolates was PCR amplified to recover the full HIV-1 genome and subjected to sequencing and phylogenetic analysis. We establish that one particular CRF_01B recombinant, with the external envelope of subtype B and the rest of the genome from CRF01_AE, is circulating widely in Thailand. Termed CRF15_01B (also referred to as CRF15), the strain was primarily heterosexually transmitted, although injecting drug use (IDU) also played a role. In aggregate data from the studies, CRF15 constituted 1.7% of all HIV-1 infections (95% confidence interval 0.5-4.4%) and was dispersed widely in the country. The previously separate heterosexual and IDU epidemics have apparently been bridged by a new CRF. The entry of CRF15 into the mainstream of the epidemic signals new complexity in the long stable molecular picture in Thailand. These recombinants must be considered in ongoing or projected efficacy evaluations of HIV-1 vaccines and antiviral therapies.

The natural history of HIV-1 subtype E infection in young men in Thailand with up to 14 years of follow-up.

OBJECTIVE: We evaluated the progression to AIDS and death among 228 men who seroconverted within a 6-month window when in the Royal Thai Army between 1991 and 1995. DESIGN AND METHODS: Men (N = 228) who seroconverted to HIV at 21-23 years of age between 1991 and 1995 were evaluated up to 14 years after HIV seroconversion. The seroconverters were matched with men who were seronegative when they were discharged from the military. In 2005-2006, the vital status was determined through the national mortality database and survivors were contacted for follow-up clinical and immunological assessment. Death certificates, medical records and next of kin interviews were used to evaluate the causes of death. RESULTS: As of March 2006, among 228 seroconverters, 56 (24.6%) were alive, 171 (75.0%) had died and one (0.4%) had undetermined status. Among 255 HIV-seronegative individuals at baseline, 15 (5.9%) had died. The median time from HIV seroconversion to death was 7.8 years. The median time to AIDS death was 8.4 years. The median times from seroconversion to clinical AIDS and a CD4 cell count less than 200 cells/mul were 7.2 years and 6.5 years, respectively. The median time from seroconversion to World Health Organization criteria for antiretroviral therapy was 6.3 years. CONCLUSION: Our data indicate a more rapid progression to AIDS and death after HIV-1 infection among young Thai men than has been reported in similar aged men who were HAART-naive in western high income countries.

The importance of militaries from developing countries in global infectious disease surveillance.

Military forces from developing countries have become increasingly important as facilitators of their government's foreign policy, taking part in peacekeeping operations, military exercises and humanitarian relief missions. Deployment of these forces presents both challenges and opportunities for infectious disease surveillance and control. Troop movements may cause or extend epidemics by introducing novel agents to susceptible populations. Conversely, military units with disease surveillance and response capabilities can extend those capabilities to civilian populations not served by civilian public health programmes, such as those in remote or post-disaster settings. In Peru and Thailand, military health organizations in partnership with the military of the United States use their laboratory, epidemiological, communications and logistical resources to support civilian ministry of health efforts. As their role in international affairs expands, surveillance capabilities of militaries from developing countries should be enhanced, perhaps through partnerships with militaries from high-income countries. Military-to-military and military-to-civilian partnerships, with the support of national and international civilian health organizations, could also greatly strengthen global infectious disease surveillance, particularly in remote and post-disaster areas where military forces are present.

The natural history of HIV-1 infection in young Thai men after seroconversion.

The natural history and progression of HIV-1 infection in Thailand and other developing countries in Asia and Africa have not been well defined. Nevertheless, valid data are needed to evaluate the effects of interventions, which are designed to delay progression. We evaluated the progression to AIDS and death in 235 men who seroconverted during their 2 years of service in the Royal Thai Army. The men were conscripted at age 21 and seroconverted within a 6-month window during follow-up while in the military. The seroconverters were matched with men who were seronegative when discharged. Of the HIV-positive men, 156 (66.4%) were alive, 77 (32.8%) had died, and 2 (0.8%) could not be located 5-7 years after their seroconversion and discharge from the military. The 5-year survival rate was 82.3%; the median times to clinical AIDS and a CD4 cell count of <200/microL was 7.4 years and 6.9 years, respectively. The mortality rate was 56.3 deaths per 1000 patient-years for HIV-positive men and 6.1 deaths per 1000 patient-years for HIV-negative men. Our data suggest a more rapid progression to AIDS and death after HIV-1 infection in young men in Thailand than has been reported for similarly aged cohorts in developed countries.