Incidence and factors associated with overweight and obesity, and hypertensive disorder, among staff in a private healthcare setting: a retrospective cohort study.

OBJECTIVE: To determine the incidence and factors associated with overweight and obesity, and hypertensive disorder, among staff in a private healthcare setting. MATERIAL AND METHOD: The present retrospective cohort study examined the computerized data of Bumrungrad International (BI) Hospital staff that had undergone pre-employment and annual/bi-annual check-ups, between January 2000 and June 2006. RESULTS: Data for the 3,678 staff surveyed comprised 7,338 visits, with a median follow-up time of 1.9 years; 81.9% were females, and the mean age (SD) was 27.1 (6.8) years. On their first visit, 8.5% could be classified as overweight or obese (Body Mass Index-[BMI] of 25.0+ kg/m2). The overall incidence of these conditions was 22.2/1,000 person-years (95%; Confidence Interval [CI] = 18.8-26.1). Cox's regression analysis revealed that incidence increased with age (Relative Hazard [RH] = 4.4 for age 20-44 years [95% -CI 1.6-12.2], and RH = 8.2 [95% CI 2.4-27.5] for age > or = 45 years, reference: < 20 years), but decreased among the registered nurses and ancillary professional staff (RH = 0.3, 95% CI 0.2-0.6). At cohort entry, 41.0% could be classified as pre-hypertensive (blood pressure 120-139/> 80-89 mmHg) and 1.9% as stages I and II hypertension. The overall incidence of hypertensive disorder was 16.9/1,000 person-years (95%; CI 13.6-20.9). Baseline pre-hypertensive (RH 4.9, 95%; CI 2.6-9.3), males (RH 1.7, 95%; CI 1.1-2. 7), age > or = 45 years (RH3.2, 95%; CI 1.0-10.5), and BMI (RH ranges 3.3-6 4) were identified as independent risk factors for incident hypertension. In addition, 2.5% were HBsAg-positive, and 33.3% had HBsAb antibody CONCLUSION: The present retrospective cohort study was instituted in a private healthcare setting, information generated resulted in changes to the health-promotion programs of the organization.

Drug use and the risk of HIV infection amongst injection drug users participating in an HIV vaccine trial in Bangkok, 1999-2003.

BACKGROUND: HIV spread rapidly amongst injecting drug users (IDUs) in Bangkok in the late 1980s. In recent years, changes in the drugs injected by IDUs have been observed. We examined data from an HIV vaccine trial conducted amongst IDUs in Bangkok during 1999-2003 to describe drug injection practices, drugs injected, and determine if drug use choices altered the risk of incident HIV infection. METHODS: The AIDSVAX B/E HIV vaccine trial was a randomized, double-blind, placebo-controlled trial. At enrolment and every 6 months thereafter, HIV status and risk behaviour were assessed. A proportional hazards model was used to evaluate demographic characteristics, incarceration, drug injection practices, sexual activity, and drugs injected during follow-up as independent predictors of HIV infection. RESULTS: The proportion of participants injecting drugs, sharing needles, and injecting daily declined from baseline to month 36. Amongst participants who injected, the proportion injecting heroin declined (98.6-91.9%), whilst the proportions injecting methamphetamine (16.2-19.6%) and midazolam (9.9-31.9%) increased. HIV incidence was highest amongst participants injecting methamphetamine, 7.1 (95% CI, 5.4-9.2) per 100 person years. Injecting heroin and injecting methamphetamine were independently associated with incident HIV infection. CONCLUSIONS: Amongst AIDSVAX B/E vaccine trial participants who injected drugs during follow-up, the proportion injecting heroin declined whilst the proportion injecting methamphetamine, midazolam, or combinations of these drugs increased. Controlling for heroin use and other risk factors, participants injecting methamphetamine were more likely to become HIV-infected than participants not injecting methamphetamine. Additional HIV prevention tools are urgently needed including tools that address methamphetamine use.

Blood and seminal plasma HIV-1 RNA levels among HIV-1-infected injecting drug users participating in the AIDSVAX B/E efficacy trial in Bangkok, Thailand.

BACKGROUND: 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. METHODS: Linear mixed models were fitted for repeated measurements of BVL. Generalized estimating equations were used to assess the difference in SVL detectability between VRs and PRs. RESULTS: A total of 196 participants became HIV-1 infected during the trial. Thirty-two (16%) became infected with HIV-1 subtype B and 164 (84%) with HIV-1 subtype CRF01_AE. Per protocol-specified analysis, there were no differences in BVL levels between VRs and PRs. When stratified by HIV-1-infecting subtype, vaccination with AIDSVAX B/E was initially associated with higher BVL among HIV-1 CRF01_AE-infected VRs compared with HIV-1 CRF01_AE-infected PRs; however, this difference did not persist over time. HIV-1 subtype B-infected VRs had slightly higher BVL levels and were more likely to have detectable SVL during the follow-up period than HIV-1 subtype B-infected PRs. CONCLUSIONS: Subtle differences in BVL and SVL were detected between VRs and PRs. These results may help to further understand the dynamics between HIV-1 vaccination, HIV-1-infecting subtypes, and subsequent viral expression in different body compartments.

Factors associated with incarceration and incident human immunodeficiency virus (HIV) infection among injection drug users participating in an HIV vaccine trial in Bangkok, Thailand, 1999-2003.

AIMS: To determine if incarceration was associated with human immunodeficiency virus (HIV) infection and identify risk factors for incarceration among injection drug users (IDUs) participating in an HIV vaccine trial in Bangkok. DESIGN: The AIDSVAX B/E HIV vaccine trial was a randomized, double-blind, placebo-controlled study. A proportional hazards model was used to evaluate demographic characteristics, risk behavior and incarceration as predictors of HIV infection and generalized estimation equation logistic regression analysis to investigate demographic characteristics and risk behaviors for predictors of incarceration. SETTING: The trial was conducted in Bangkok Metropolitan Administration drug-treatment clinics, 1999-2003. PARTICIPANTS: A total of 2546 HIV-uninfected IDUs enrolled in the trial. MEASUREMENTS: HIV testing was performed and an interviewer-administered questionnaire was used to assess risk behavior and incarceration at baseline and every 6 months for a total of 36 months. FINDINGS: HIV incidence was 3.4 per 100 person-years [95% confidence interval (CI), 3.0-3.9] and did not differ among vaccine and placebo recipients. In multivariable analysis, being in jail (P < 0.04), injecting (P < 0.0001), injecting daily (P < 0.0001) and sharing needles (P = 0.02) were associated with HIV infection and methadone maintenance was protective (P = 0.0006). Predictors of incarceration in multivariable analysis included: male sex (P = 0.04), younger age (P < 0.0001), less education (P = 0.001) and being in jail (P < 0.0001) or prison (P < 0.0001) before enrollment. CONCLUSIONS: Among IDUs in the AIDSVAX B/E trial, incarceration in jail was associated with incident HIV infection. IDUs in Thailand remain at high risk of HIV infection and additional prevention tools are needed urgently. HIV prevention services, including methadone, should be made available to IDUs.

Diarrhea among children admitted to a private tertiary-care hospital, Bangkok, Thailand: a case series.

We report here a case series of pediatric diarrhea cases admitted to a private tertiary-care hospital in Bangkok, Thailand. Retrospective data were collected from computerized medical records of 2,001 children with diarrhea (80.9% Thai), ages birth to 14 years, admitted to our facility during 2000-2005. The most common symptom leading to admission was vomiting (34.6%), while the most common sign was dehydration (63.6%). The largest proportion was comprised of toddlers (45.4%), followed by infants (24.2%). Of the total 2,564 admissions, 1,874 (73.1%) stool samples were collected and examined for red blood cells (RBC) and white blood cells (WBC); 57.1% and 70.6% were negative for RBC and WBC, respectively. Of the 1,878 blood specimens collected for electrolytes, 21.6% show acidosis. Of 1,793 stool specimens collected, the majority revealed normal flora (72.9%). Enteropathogenic Escherichia coli (EPEC) were seen in 10.8%. Campylobacter jejuni was found in only 2.9% of specimens, while of 1,065 specimens tested for rotavirus antigen, 23.9% were positive. In addition to bacterial cultures and their anti-microbial sensitivities, factors associated with rotavirus infection, C. jejuni, and metabolic acidosis, were also explored in this study. Rotavirus infections were more likely to be associated with children older than toddlers (3-14 years old), being admitted within the first day of the symptoms, those who were more acidotic, and was more common in the first 3 months of each year. Our data were little different from community-acquired infections reported among the general population.

Radiologic findings in tsunami trauma: experience with 225 patients injured in the 2004 tsunami.

The objective of this study was to determine the spectrum of radiographic findings, frequency, and type of injuries in tsunami victims. From December 2004 to May 2005, all tsunami victims admitted to our hospital were retrospectively identified by a search of medical records. Patients who received radiologic examinations were reviewed for their radiographic findings. The authors identified 225 tsunami victims. One hundred eight victims received radiologic evaluations on admission that included 350 plain radiographs, 19 ultrasound exams, 18 computed tomography (CT) scans and 3 magnetic resonance imaging (MRI) scans. Overall positivity rate was 48% (187/390). Most common trauma involved musculoskeleton (102/187, 54.5%). Retained foreign bodies in soft tissues, pneumonia/aspiration, and tsunami sinusitis were found in 22, 28, and 31 patients (9.8, 12.4, and 13.8%), respectively. These were unique findings in tsunami trauma. Imaging played an important role in detection of these abnormalities.

Intussusception in a private tertiary-care hospital, Bangkok, Thailand: a case series.

This was a retrospective case series study of patients with intussusception at a private tertiary-care hospital in Bangkok, Thailand. The computerized hospital records of all 94 children aged 0-14 years diagnosed with intussusception from 2000 to 2005 were reviewed. About half (51.1%) were males, 23.4% were less than 1 year old. Most (78.7%) were Thai nationals. The highest case frequency was in August (n=12, Poisson means = 7.8, 95% confidence interval 6.3-9.6). Of these, none had the classical triad of vomiting, colicky pain, and mucous bloody stools. Only 12.8% had fever; abdominal mass was detected in 4.3%, and 4.3% had increased bowel sounds, while 34.0% had no specific signs. The most frequent site of intussusception was the ileocolic (62.6%). Stool cultures for bacteria and stool for rotavirus antigen obtained in some cases revealed no significant findings. Of the cases, 10 (10.6%) had spontaneous reduction, 84 (89.4%) underwent barium enema intervention, 10 of the latter (11.9%) required further surgical intervention. There were no mortalities during the observation period. There were 10 recurrent events in this series. The 7-day recurrence-free probability was 84.9% (95% CI 49.2, 96.3%). This study provides baseline data regarding intussusception in Thailand which may be useful for future epidemiological and/or clinical studies.

Social harms in injecting drug users participating in the first phase III HIV vaccine trial in Thailand.

OBJECTIVE: To study related social harms due to identification with a group of participants in an HIV-1 vaccine trial who are potentially high risk for HIV/AIDS. MATERIAL AND METHOD: Two thousand five hundred forty six injecting drug users (IDU) were enrolled in a 36-month vaccine trial. Volunteers received education and risk reduction counseling at every six-month study visit. Social harms were not actively solicited, but volunteers were encouraged to report any during the process of counseling at every six-month visit. If a social harm was reported, a questionnaire was administered and the harm was tracked If necessary, clinic staff assisted in resolving the social harm. RESULTS: Thirty-nine social harms were reported by 37 participants; 33 (84.6%) were disturbances in personal relationships, three (7.7%) in employment, one (2.6%) was medically related, one (2.6%) was related to admission in the military and one (2.6%) was related with misbelieve about the vaccine. The most common reason for disturbances in personal relationships was suspicion of HIV infection (n=20). The impact of these harms on quality of life was characterized as minimal by 31 (79.5%) participants, as moderate by seven (17.9%), and as major by one (2.6%). All social harms were documented to be resolved by the end of the study. CONCLUSION: A few participants reported study-related social harms during the course of the trial. Most harm had minimal impact and all could be resolved by the end of the present study.

Missed appointments at a tuberculosis clinic increased the risk of clinical treatment failure.

We investigated the charts of 381 new smear-positive tuberculosis patients at Khon Kaen Medical School during 1997-2001 using World Health Organization definitions to evaluate associations among treatment success or failure (defaulted, failed, died, or not evaluated) and tuberculosis clinic contact, demographics and clinical characteristics of the patients. Multinomial logistic regression was used for three-category outcome analysis: treatment success, transferred-out and clinical treatment failure. The treatment success and clinical treatment failure rates were 34.1% and 34.4%, respectively. About 46.5% and 85.8% of patients missed appointments at the tuberculosis clinic in the treatment success and treatment failure groups, respectively. The results show that patients who were absent from the tuberculosis clinic were 5.95 times more likely to have clinical treatment failure than treatment success, having adjusted for the effect of transfering-out and the effect of the treatment regimen and the sputum conversion status (adjusted odds ratio = 5.95; 95% CI: 2.99 to 11.84). The review showed that absence from the tuberculosis clinic was an independent risk factor for clinical treatment failure. We recommended that all new smear-positive tuberculosis patients should be followed closely at a tuberculosis clinic.

Modified Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) as a screening test for dementia for Thai elderly.

A potential test for early detection of dementia in the elderly is the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE), which is based on information from the informant for the elderly about the changes of the elderly in everyday cognitive functioning associated with dementia. The present study aimed to modify and assess the reliability and validity of the modified IQCODE consisting of 32 items. The study consisted of two methods of assessing dementia: DSMIV diagnosis carried out by clinicians, and informants responding to the IQCODE. The subjects were 200 pairs of elderly subjects and their informants who visited the Geriatric Clinic, Ramathibodi Hospital. The optimal cutoff score on the modified IQCODE was 3.42, with 90% sensitivity and 95% specificity. The positive predictive values, negative predictive values, and accuracy were 0.94, 0.90, and 0.92, respectively. The IQCODE items had high internal consistency. The IQCODE associated with the elderly person's age, but not with their gender and educational level; nor were they associated with the demographic characteristics of the informant. Therefore, the IQCODE could be used as an alternative screening test for dementia in Thailand with acceptable sensitivity and specificity. This tool may be useful for dementia screening in the community and the geriatric clinic for early detection of disease.

The prevalence of lower genital tract infections among ante-natal care (ANC) clinic patients in two central hospitals, Vientiane, Lao People's Democratic Republic.

This study of lower genital tract infections in pregnant women attending antenatal clinics in Vientiane, Lao PDR is a response to the reported rapid increase in the number of HIV infections in neighboring countries, and is a recognition of the important role of reproductive tract infections in facilitating HIV transmission. This cross-sectional study determines the prevalence of lower genital tract infections among 500 antenatal attendees (gestational age < or = 20 weeks) attending two hospitals serving urban areas in Vientiane, between September 2001 and March 2002. Most participants were housewives (64.4%) and government workers (16.0%). Their husbands were mainly government officers (31.4%), laborers or farmers (30.2%), and businessmen (12.4%). Sixty-four percent reported a past history of "any vaginal complaints" with 44.2% having sought treatment. Candida spp had the highest prevalence of all infections (27.0%), followed by bacterial vaginosis (14.4% by Amsel's criteria and 22.0% by Nugent's score), C. trachomatis (10.2% by nucleic acid hybridization and 9.6% by PCR), T. vaginalis (1.8%), and N. gonorrhoeae (0.8%), but no syphilis serological markers. Taken in conjunction with other surveillance data from the same period, this study indicates an opportunity to prevent epidemic spread into the community of both sexually transmitted disease and HIV by appropriate preventative programed activities, including treatment services targeted at higher risk community groups.

Factors related to volunteer comprehension of informed consent for a clinical trial.

The informed consent process has become a universal requirement for research involving human subjects. Its goal is to inform volunteers regarding research in order to make decision to participate or not. This study aimed to measure volunteers' comprehension levels concerning the clinical trial and to find out factors associated with that comprehension levels. Eighty-one volunteers who enrolled in a malaria clinical trial were recruited into the study. A semi-structured questionnaire was used to collect the information. Non-participant observation was used to observe the process of informed consent. Volunteers were interviewed three days after being recruited into the trial. The results show the volunteers' comprehension was low. Only 44% of volunteers had an acceptable level of comprehension. It also revealed that 20 volunteers were not aware of being volunteers. Most volunteers knew about the benefits of participating in the trial and realized that they had the right to withdraw from the study, but not many knew about the risks of the trial. The results indicated the method of informing about the trial affected the volunteers' comprehension level. No relationship was found between comprehension level and volunteers' socio-demographic characteristics and their attitude toward the consent process. The findings from this study demonstrate volunteers who participated in the clinical trial were not truly informed. Further studies regarding enhancing volunteers' understanding of the trial are needed.

A bedside prediction-scoring model for late-onset neonatal sepsis.

OBJECTIVE: Insufficient tools for bedside prediction of late-onset neonatal sepsis (LNS) initiated this study. The objective was to develop and validate a simple prediction-scoring model for LNS defined as culture-proven sepsis occurring 72 hours after birth. METHODS: The study was performed at a university hospital in Bangkok. The derivation phase included medical records of 1870 neonates, randomly selected from 9347 records of neonates who had been hospitalized for >72 hours during 1998 to 2000, of which 1824 records were available. In all, 100 neonates were clinically suspected of sepsis and 17 had proven LNS. The validation phase included 73 neonates suspected of having sepsis during July 2002 to June 2003 and 25 who had LNS. Weighted coefficients from Cox's proportional hazards model and receiver-operating-characteristic (ROC) curve analysis were used. RESULTS: The incidence density of LNS was 17/11355 (1.5/1000) person-days. A scoring model was developed and consisted of the following: hypotension (score 4), abnormal body temperature (score 3), respiratory insufficiency (score 2), neutrophil band form fraction >1% (score 2), platelet count <150 x 10(3)/microl (score 2), and umbilical venous catheterization (1 to 7 or >7 days; score 2 or 4). The area under the ROC curves for prediction of LNS in a neonate suspected of sepsis in each of the two phases was 0.85 and 0.80, respectively (p=0.436). The mean probabilities of LNS were approximately 0.10 (low risk) for scores from 0 to 3; 0.50 (intermediate risk) for scores from 4 to 6; and 0.70 (high risk) for scores > or =7. CONCLUSION: A simple prediction-scoring model for LNS was developed. Validation of the scores suggested good diagnostic performance.

Development of multiplex PCR for the detection of total coliform bacteria for Escherichia coli and Clostridium perfringens in drinking water.

Multiplex PCR amplification of lacZ, uidA and plc genes was developed for the simultaneous detection of total coliform bacteria for Escherichia coli and Clostridium perfringens, in drinking water. Detection by agarose gel electrophoresis yielded a band of 876 bp for the lacZ gene of all coliform bacteria; a band of 147 bp for the uidA gene and a band of 876 bp for the lacZ gene of all strains of E. coli; a band of 280 bp for the p/c gene for all strains of C. perfringens; and a negative result for all three genes when tested with other bacteria. The detection limit was 100 pg for E. coli and C. perfringens, and 1 ng for coliform bacteria when measured with purified DNA. This assay was applied to the detection of these bacteria in spiked water samples. Spiked water samples with 0-1,000 CFU/ml of coliform bacteria and/or E. coli and/or C. perfringens were detected by this multiplex PCR after a pre-enrichment step to increase the sensitivity and to ensure that the detection was based on the presence of cultivable bacteria. The result of bacterial detection from the multiplex PCR was comparable with that of a standard plate count on selective medium (p=0.62). When using standard plate counts as a gold standard, the sensitivity for this test was 99.1% (95% CI 95.33, 99.98) and the specificity was 90.9 % (95% CI 75.67, 98.08). Multiplex PCR amplification with a pre-enrichment step was shown to be an effective, sensitive and rapid method for the simultaneous detection of these three microbiological parameters in drinking water.

HLA class II (DRB1, DQA1 and DQB1) allele and haplotype frequencies among HIV-infection discordant Thai couples.

We investigated the association of HLA-DRB1, -DQA1 and -DQB1 alleles and haplotypes in 33 Thai HIV discordant couples. A significantly lower frequencies of DRB1*14 (3.0% vs 11.3%, p = 0.048) and DQA1*0103 (0.0% vs 5.63%, p = 0.042) alleles were found in the seropositive individuals when compared with HIV-negative controls. In contrast, there was no significant difference in HLA-DQB1* allele frequencies. The haplotype analysis revealed that DRB1*1501-DQA1*0102-DQB1*0601 (7.6% vs 0.0%, p = 0.002), DRB1*0405-DQA1*0302-DQB1*0401 (7.6% vs 1.3%, p = 0.024) and DRB1*1401-DQA1*0104-DQB1*05031 (6.1% vs 0.0%, p = 0.007) were found to be significantly higher frequencies when compared between HIV seronegative partners and HIV negative controls, but DRB1*1501-DQA1*0102-DQB1*0502 (0.0% vs 8.1%, p = 0.01) was significantly lower. The DRB1*1602-DQA1*0101-DQB1*0502 (4.6% vs 0.0%, p = 0.024) haplotype was found to be significantly higher frequencies in HIV seropositive individuals when compared to HIV negative controls but the DRB1*1502-DQA1*0101-DQB1*0501 (1.5% vs 8.1%, p = 0.049) haplotype was lower.

Phase I/II study of a candidate vaccine designed against the B and E subtypes of HIV-1.

A phase I/II trial of a candidate vaccine to prevent HIV infection was carried out in Bangkok, Thailand, testing AIDSVAX B/E (VaxGen, Inc., Brisbane, CA), a bivalent subunit vaccine prepared by combining recombinant gp120 from a subtype B virus (HIV-1MN) with gp120 from a subtype E virus (HIV-1A244) in alum adjuvant. The studies provide human data on the immunogenicity of various dose combination of non-subtype B vaccine antigens. The results suggest that AIDSVAX B/E is safe and immunogenic in humans. The optimal dose for humans in developing countries was 300 microg of each antigen (B and E). Clade E responses were measurably increased by immunizing with gp120 B/E over B alone. Using the B/E combination did not interfere with the response to either clade. Antibodies to AIDSVAX B/E were able to bind to oligomeric gp120 on the surface of cells infected with primary isolates of HIV-1.

Sexual risk reduction in a cohort of injecting drug users in Bangkok, Thailand.

OBJECTIVE: 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. METHODS: A total of 806 IDUs participated in the Bangkok HIV Vaccine Trial Preparatory Cohort Study from 1995-1998 and remained in the study for at least 4 follow-up visits (approximately 16 months). Participants received HIV counseling and testing every 4 months and free condoms were provided. Structured interviews including questions on sexual behavior were administered every 4 months. RESULTS: Approximately 40% of participants reported engaging in unprotected sex (vaginal intercourse without always using a condom) with a regular partner at each study visit, without any decline over time in this behavior. There were declines in the proportions of participants reporting unprotected sex with casual partners and with paid partners (men only) over time, but the declines were confined to the early period of the study. Unprotected sex with casual partners was associated with amphetamine use. Condom use increased substantially among participants who seroconverted for HIV during the study. CONCLUSIONS: Interventions to reduce sexual risk behavior among HIV-seronegative IDUs over extended periods were no more likely to be effective than shorter interventions. New programs are needed to reduce sexual risk behavior among amphetamine users and among IDUs who are currently seronegative but are engaging in injection risk behaviors and in unprotected sex with regular partners.

Early markers of HIV-1 disease progression in a prospective cohort of seroconverters in Bangkok, Thailand: implications for vaccine trials.

BACKGROUND: 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 and CD4 cell counts in recent HIV-1 seroconverters to inform selection of these endpoints. METHODS: We studied 130 newly HIV-1-infected injection drug users identified from a prospective cohort of initially uninfected persons in Bangkok during 1995 through 1998. We analyzed trends in HIV-1 viral loads and CD4 cell counts as well as progression to the surrogate endpoint, defined as 2 consecutive CD4 cell counts of fewer than 350 cells/mm, during 24 months after the first HIV-1 seropositive (FP) visit. RESULTS: Median HIV-1 RNA copies/mL with interquartile ranges were 43,693 (14,320-94,767) at the FP visit, 46,924 (16,273-104,314) at 6 months, 28,446 (11,292-54,325) at 12 months, and 18,080 (8713-54,059) at 18 months. HIV-1 viral loads at the FP visit and at 18 months were positively correlated (r = 0.53, P < 0.0001). Of 130 participants, 12% reached the surrogate endpoint by 6 months, 16% by 12 months, and 27% by 18 months. In Cox regression analyses, HIV-1 viral loads of more than 50,000 copies/mL at the FP visit (hazard ratio [HR] = 2.3, 95% confidence interval [CI]: 1.1-4.8) and first CD4 cell count of 500 or fewer cells/mm (HR = 7.6, 95% CI: 3.2-17.6) were independently associated with faster progression to the surrogate endpoint. CONCLUSIONS: Participants with high HIV-1 RNA levels and low CD4 cell counts close to the time of seroconversion were more likely to experience early immunologic progression. Approximately one quarter of seroconverters reached the surrogate immunologic endpoint within 18 months of their FP visit and before starting ART, suggesting the utility of this endpoint for analyses of VEp in some ongoing and planned HIV-1 vaccine efficacy trials.

Recruitment, screening and characteristics of injection drug users participating in the AIDSVAX B/E HIV vaccine trial, Bangkok, Thailand.

OBJECTIVES: 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 assumptions. METHODS: Enrollment for both studies was conducted at Bangkok narcotic treatment clinics, where a standardized questionnaire was administered on demographics, risk behavior and incarceration history over the previous 6 months. RESULTS: During 1999-2000, 4943 IDU were screened for enrollment; successful sources of recruitment included clinic attendees (43.4%), an IDU referral program (20.4%) and preparatory cohort participants (14.7%). Of those screened, 1689 (34%) were HIV seropositive (HIV subtype B 23.6%; subtype E 76.4%). Of the 2545 enrolled, 93.4% were male. Compared with cohort IDU, trial IDU were younger (mean age: 28.8 versus 31.3 years), better educated (secondary level or higher: 67.2% versus 58.7%), and less likely to inject drugs daily (39.4% versus 90.4%); they were more likely to have been incarcerated (78.4% versus 65.7%), have recently injected stimulants (14.8% versus 5.8%) and tranquilizers (11.5% versus 2.3%), and obtained needles/syringes from a source other than a pharmacist (7.2% versus 3.9%) (all P < or = 0.003). CONCLUSIONS: IDU at high risk for HIV have been successfully enrolled in the AIDSVAX B/E efficacy trial. Only minor epidemiologic differences were found at enrollment between trial and preparatory cohort IDU. The latter has proven critical in guiding trial design; results are expected in late 2003.

Simultaneous determination of trans, transmuconic acid and s-phenylmercapturic acid by high pressure liquid chromatography and its application.

The simultaneous determination of urinary trans,trans-muconic acid (t,t-MA) and S-phenylmercapturic acid (S-PMA) was performed by liquid extraction with ethyl acetate and reversed-phase high performance liquid chromatography (RP-HPLC) on a Hypersil-ODS column using the gradient mobile phase of methanol and 0.0012 N perchloric acid and diode array detection at 205 and 264 nm for S-PMA and t,t-MA, respectively. The retention times for t,t-MA and S-PMA were 3.8 and 12.3 minutes, respectively. The recoveries of t,t-MA and S-PMA were > 97%; between-day precisions were all within 8% RSD (100x SD/mean). The method was applied to analyze the urinary t,t-MA and S-PMA of 59 service station attendants exposed to average benzene concentrations in the air of 0.20+/-0.18 ppm. Significant differences in pre-shift and post-shift urinary t,t-MA between smokers and non-smokers were found.