Royal Thai Army Research Articles

Comparison of Clinical Pathology Examination Scores and Grade Point Averages of Royal Thai Army Medical Cadets

This retrospective study assesses the relationship between clinical pathology (CP) examination scores and grade point averages (GPAs) of Royal Thai Army (RTA) medical cadets. Altogether, 411 of the third-year RTA medical cadets studying CP at Phramongkutklao College of Medicine in 1995-2001 were included in this study. Correlations between CP examination scores, clinical year GPAs, and cumulative GPAs were analyzed by using Pearson's product-moment correlation coefficient. The CP scores showed positive correlations (p < 0.01) with GPAs in the clinical years (4th to 6th) of study (r = 0.616, r = 0.602, and r = 0.540) and cumulative GPAs (r = 0.698). These significant findings may be attributable to the integration of small group teaching and case study discussions, together with traditional lectures and laboratory practice, in the CP course. Our results indicate that CP examination scores can be used as a reliable predictor of success in the 6-year course of study for RTA medical cadets.

Foundations for a Phase III human immunodeficiency virus vaccine trial: A decade of Thai-U.S. Army collaborative research.

As part of the response of the Royal Thai Army to the outbreak of human immunodeficiency virus (HIV) in Thailand, a collaboration was established with the U.S. Army to jointly work toward the development of vaccines for the prevention of HIV infection. During the first decade of this collaboration, studies have been carried out in the diverse disciplines that are crucial to providing the foundations for efficacy trials of candidate HIV vaccines. Studies of host, pathogen, and vaccine interventions included studies of viral diversity, epidemiology, disease course, potential vaccine cohorts, and Phase I/II clinical trials. Collaborations were expanded to other Thai institutions and to overseas partners, resulting in the Thai AIDS Vaccine Evaluation Group. The efforts of these collaborations resulted in the development of candidate vaccines specifically designed for use in Thailand, and sequential evaluations that have lead to the threshold of the world's next and largest efficacy trial of HIV vaccines.

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.

Thalassemia screening among Royal Thai Army medical cadets.

Thalassemia, common in Thailand, varies from mild to severe anemia, resulting in work inefficiency, particularly during exertion. Therefore, it is important for military cadets to be screened. The objective of this study was to screen for thalassemia and hemoglobinopathies among Royal Thai Army medical cadets. We tested 358 third-year Royal Thai Army medical cadets for complete blood count, red blood cell indices, hemoglobin (Hb) typing, inclusion bodies, and Hb A2, and Hb E. DNA analysis confirmed alpha-thalassemia, trait detection. The Hb E trait was the most frequent, respectively, in men and women, at 12.61% and 12%, followed by the a-thalassemia1 trait, at 3.3% and 4% and the beta-trait, at 1.5% and 0%. Two cases of homozygous Hb E were found only in men. Interestingly, a mild form of 1-thalassemia/Hb E was found in one male RTA medical cadet. These findings suggest that consistent thalassemia screening should be considered.

Thailand's Prime-Boost HIV Vaccine Phase III

The Thailand Ministry of Public Health will pursue the Prime-Boost HIV Vaccine Phase III Trial in Chon Buri and Rayong provinces, as planned. The Ministry and collaborating institutions remain confident in the scientific merit of the prime-boost vaccination concept and the combined immune response induced by ALVAC-HIV vCP1521 and AIDSVAX B/E, as demonstrated in Phase I and II safety and immunogenicity studies conducted in Thailand. The Ministry is aware of the comments made by 22 scientists in a recent Policy Forum in Science (D. R. Burton et al. , 16 Jan., p. [316][1]; see also the related Policy Forum on p. [961][2]). Although we welcome constructive input, we find the underlying premise of the Policy Forum flawed in that it uses data from efficacy trials of a single vaccine concept to predict the results of a prime-boost combination vaccine study. Only by conducting the trial will we be able to determine if the combination of two candidate vaccines will induce both cellular and humoral immunity and protect against HIV infection. Both the Screening Protocol and Vaccine Protocol of the Prime-Boost Study were reviewed and endorsed by Institutional Review Boards and Expert Committees in Thailand and the United States, and by the World Health Organization (WHO)/UN AIDS Programme (UNAIDS). Thailand's leading researchers, all of whom have international standing and extensive experience in AIDS vaccine studies, from the Faculty of Tropical Medicine, Mahidol University; the Armed Forces Research Institute of Medical Sciences, Medical Corps, Royal Thai Army; and the Thai AIDS Vaccine Evaluation Group, are involved in the conduct of this trial under the Ministry of Public Health. The Prime-Boost Study was carefully considered within multiple venues, including a special WHO/UNAIDS/Centers for Disease Control consultation on the impact of the lack of efficacy of the AIDSVAX trials in North America and Thailand, which concluded that “because of its independent scientific rationale,” it was appropriate to go forward with efficacy evaluation of the prime-boost combination. There is no such thing as wasting time or money in researching an AIDS vaccine. Regardless of the efficacy results, Thailand is benefiting from conducting this trial in several areas: Experience will be gained by its scientists and health workers, and its laboratory infrastructure and specimen archiving will be strengthened. Close collaboration has also been established with NGOs and community groups to plan and implement community engagement activities. Another important gain is the intensified HIV/AIDS awareness campaign around the trial, which directly benefits the local communities in Chon Buri and Rayong. Thailand intends to share knowledge and experience gained and lessons learned in conducting this large-scale community-based efficacy trial. Needless to say, if the vaccine is proven efficacious, other countries will benefit as well. The Ministry of Public Health will continue to strive to find the best preventive measure to stop the spread of HIV. It is the Ministry's responsibility to further reduce the yearly HIV infection rate in Thailand, which is currently 25,000. [1]: /lookup/doi/10.1126/science.1094620 [2]: /lookup/doi/10.1126/science.1096161

Thailand report: HIV/AIDS surveillance 1998.

Patients identified as having symptomatic HIV infection or AIDS have been reported to the Division of Epidemiology (DOE), in the Thai Ministry of Public Health (MOPH) since 1984. In addition, since 1989, the DOE and the Royal Thai Army have conducted annual serosurveillance of HIV in particular populations. Sexual behavior surveys have been conducted annually since 1995. HIV prevalence among direct commercial sex workers (CSWs) peaked in 1994 (33%) but has declined to 22%. Prevalence among male CSWs reached 18% in 1994 but has not changed since. HIV prevalence among blood donors was 1% in 1992, but has declined to 0.5%. HIV prevalence among pregnant women peaked in 1995 (2.3%) and has since declined to 1.5%. HIV prevalence among 21-year-old male conscripts peaked in 1993 (4%), but declined to 1.9% in 1998. Prevalence among IDUs has remained between 30%-40% since the late 1980's. The number of reported AIDS cases was 128,606 by October of 1999, and has increased yearly. Nonetheless this figure is likely unreliable due to significant underreporting. Thailand's surveillance program appears to be effective in increasing public knowledge and information about the epidemic, although it faces growing problems of good data management, interpretation, timely distribution of information, and investigation of abnormal events.

In-vitro cultivation: a sensitive method for detecting Blastocystis hominis.

Currently, the detection of human infection with Blastocystis hominis is usually based on the examination under a light microscope of faecal samples, either directly, as 'simple smears', or after some form of concentration. Whether short-term, in-vitro cultivation would increase the sensitivity of such detection remains a matter of controversy. Over 900 fresh stool specimens, from soldiers in the Royal Thai Army, were each checked for the parasite using three methods: simple smears; formalin-ethyl-acetate concentration; and cultivation in Jones' medium. Although 334 of the samples were found to be culture-positive, the parasites were only detected in 142 of the simple smears, and faecal concentration led to an even lower sensitivity (64 positive samples). In-vitro cultivation does seem worthwhile in the detection of B. hominis carriage in field studies.

Explosive spread and effective control of human immunodeficiency virus in northernmost Thailand: the epidemic in Chiang Rai province, 1988-99.

The human immunodeficiency virus type 1 (HIV-1) epidemic began in Asia later than most in other regions but then spread very rapidly. Upper northern Thailand was severely affected, with among the highest infection rates in Asia. The first 12 years of the HIV epidemic in Chiang Rai, Thailand's northernmost province are described. HIV infection was not reported in Chiang Rai until 1988 but, within a few years more than half of the brothel-based female sex workers and one in six of 21-year-old male Royal Thai Army conscripts from the province were HIV infected. Infection rates in Chiang Rai have since declined following an aggressive prevention campaign, but the number of AIDS cases continues to mount, along with profound demographic, social and economic effects.

Education and research links between the UK and Thailand.

Understanding the cultural contexts of training nurses in different countries is an important element for all nurse educators. In understanding other cultures we may be better prepared to understand our own. This paper identifies some similarities and differences between nurse education in Thailand and the UK. A notable difference is that 'Thai culture' is taught in Thai educational programmes whereas equivalent programmes are perhaps missing from UK colleges of nursing. The paper closes by identifying an on-going research project into 'academic levels in nursing' that has been developed between the Royal Thai Army Nursing College, Bangkok and the School of Nursing and Midwifery Studies, University of Wales College of Medicine, Cardiff.

Willingness to participate in HIV-1 vaccine trials among young Thai men

Objectives: Willingness to participate in HIV-1 vaccine trials and associated factors were investigated in a sample of 2670 Royal Thai Army conscripted recruits. Methods:Self administered questionnaires were used. Data were...

HIV Risk Behavior Patterns Among Young Thai Men

Correlates of behavior associated with HIV exposure risk were evaluated in cross-sectional data from 3,839 Royal Thai Army (RTA) recruits whose birthplaces and residences were located away from Thailand's main HIV epicenter. Participants were generally 21 years old, unmarried, educated at the primary school level, and previously had been engaged in agriculture or unskilled labor. HIV prevalence in the sample was 1.8%. Condom use with commercial sex workers (CSW) was less than universal, and a small subset of men emerged who had multiple categories of partners. Nonetheless, CSW patronage appeared lower than in early studies in the Thai epicenter of the Upper North, and the venues patronized generally were not low-cost, high-turnover brothels. Sexual experience with girlfriends was more frequent than CSW experience, and the rate of condom use with girlfriends was relatively low. Lifetime injection drug use (IDU) was reported by 4.1% of the total sample and was associated with recent urban residence, CSW patronage, and sexual precocity. Findings suggest gaps in Thailand's condom campaign and the need to better address HIV risk associated with having multiple partners.

HIV Infection and Risk Behaviors in Thai Men After Their Service in the Royal Thai Army: Informing Vaccine Cohort Development

A cohort of Royal Thai Army (RTA) conscripts was followed in civilian life after completing 2 years of military service, to determine whether such a cohort might be suitable for HIV vaccine trials. Objectives were to identify correlates of participation and to determine the occurrence of risk behaviors for HIV infection after discharge from the military. The cohort was selected from among conscripts who had participated in HIV studies from 1991 to 1993. Risk factors were surveyed at 3, 9, and 15 months after discharge (1993–1995). Change in risk was evaluated based on deviations from expected distributions of risk categories for sentinel behaviors, assessed with chi-square analysis. HIV seroconversion rates (SR) and 95% confidence intervals (CI) were calculated. A total of 380 men returned after discharge. Seven men seroconverted after discharge; the SR (95% CI) was 2.02/100 person-years (0.81–4.17). Among changes in risk were reduced visits to commercial sex workers (CSWs), more condom use with CSWs, and less alcohol use prior to CSW visits. Behaviors associated with increased risk of HIV seroconversion declined after military service. Thus, sufficient numbers of outcome events for vaccine trials may not be attained with this type of cohort. Nonetheless, these findings provide data on the dynamics of the HIV epidemic in Thailand and the development of HIV vaccine cohorts.

Nationwide surveillance of HIV-1 prevalence and subtype in young Thai men.

As part of routine surveillance, an HIV-1 serosurvey of 366,074 members of successive cohorts of young Thai men entering service with the Royal Thai Army (RTA) was conducted between November 1989 and November 1995. We analyzed regional and temporal trends in HIV-1 seroprevalence in young men in Thailand and determined the proportion of infections resulting from subtypes E and B in this population in 1992 and 1995. The prevalence in 1992 was compared with that in 1995 by region and demographic group. The HIV-1 subtype was determined in a random sample of HIV-1-positive specimens in 1992 and 1995 using a V3 peptide enzyme immunoassay. From a peak of 3.7% in 1993, overall seroprevalence declined to 3.0% in 1994 and further in 1995 to 2.5%. Between 1992 and 1995, the absolute decrease in seroprevalence was greatest in the upper North (from 12.5% to 5.3%), where the prevalence has been the highest. Overall, 96.9% and 95.9% of typable specimens were determined to be subtype E in 1992 and 1995, respectively. Decline in HIV-1 seroprevalence among young men in Thailand has continued, which suggests that HIV control programs in Thailand may have been successful in decreasing spread of HIV-1. Almost all HIV-1 infections resulted from subtype E.

Sexual behavior of young men in Thailand: regional differences and evidence of behavior change.

An anonymous, self-administered behavioral survey was conducted in Royal Thai Army (RTA) conscripts from 19 provinces throughout Thailand in May 1996. All (to a maximum of 350) Thai men who entered the RTA in each province were selected. Data from 5474 men were included in this analysis. High-risk behaviors were reported nationwide; however, some regional differences were found. Men from the upper North were more likely to have had a commercial sex worker (CSW) as their first sexual partner (42%) than men from any other region. However, in the past year, reported sex with CSWs in the upper North (41%) was similar to or lower than those in other regions. Consistent condom use with CSWs was higher in the North than in any other region. Condom use at first sex with CSWs increased with later years at first sex in all regions. These data suggest that past higher-risk behavior among young men in the upper northern part of Thailand may have contributed to the concentration of the HIV epidemic in that region. Risk behaviors, particularly unprotected sex, appear to be decreasing nationwide.

Antibodies to Orientia tsutsugamushi in Thai soldiers.

Thai soldiers who were conscripted, Royal Thai Army forces, professional Border Patrol Police, or local militia (Thai Rangers) located in any of seven provinces of Thailand were bled in April and again, four months later, in July 1989. In 1991, soldiers from five different locations in southern Thailand were bled once, in July. Serum samples were tested by indirect fluorescent antibody assay for antibody to Orientia (formerly Rickettsia) tsutsugamushi, etiologic agent of scrub typhus, with any titer > or = 1:50 considered positive. Prior to field exercises, prevalence of antibody varied significantly between different types of units, ranging between 18.6% for Thai Rangers and 6.8% for the Royal Thai Army. The April prevalence, July prevalence, and incidence varied significantly by province in 1989, with highest incidence being 14.5% in Kanchanaburi and the lowest 0% in Utraladit. The prevalence in southern Thailand in 1991 varied between 1.6% and 6.8%. The data demonstrate that O. tsutsugamushi is widely distributed in Thailand and that military activity consisting of field exercises that simulate combat conditions significantly expose soldiers to infection.

Correlates of HIV-1 seropositivity among young men in Thailand.

Geographic and demographic correlates of risk for HIV-1 seropositivity were studied in 120,216 young men selected by lottery for service in the Royal Thai Army (RTA). The study population consisted of men selected between November 1991 and May 1993. Venous blood was collected at induction, and a brief demographic questionnaire was administered. HIV-1 seropositivity was established by Western blot confirmation of duplicate reactive ELISAs. Geographic variable provided the strongest correlate of risk, clearly distinguishing residents of the upper north, Bangkok, and the central region from the northeast. Overall 12.2% of men from the upper north were HIV-positive. Men who had lived in rural areas were at less risk in most regions of the country, but had equal risk in the upper north. Unmarried men and those with less education were at higher risk throughout the country. These data provide valuable information on the prevalence of HIV infection in one segment of the general population. Continued surveillance of this group will facilitate evaluation of Thailand's response to the epidemic.

Risk Factors for HIV-1 Seroconversion Among Young Men in Northern Thailand

To identify behavioral and sociodemographic risk factors for incident human immunodeficiency virus-1 (HIV-1) infection among healthy young men in northern Thailand. Men inducted into military service in northern Thailand in May and November 1991 were followed at 6-month intervals until discharge 2 years later. Trained nonmilitary interviewers identified risk factors for HIV-1 infection through interviews with the men. Thirteen military bases in northern Thailand. A total of 1932 seronegative men, aged 19 to 23 years (average age, 21 years) at enrollment, conscripted into the Royal Thai Army and Air Force from six upper-northern Thai provinces. Human immunodeficiency virus-1 seroincidence as determined through enzyme-linked immunosorbent assay and verified by Western blot, and univariate and multivariate analyses of risk factors related to HIV-1 incidence. A total of 85 men seroconverted to HIV-1 over the period of observation, giving an incidence rate of 2.43 per 100 person-years. Factors strongly associated with HIV-1 seroconversion were frequency of visits to female commercial sex workers (CSWs), sex with men, and incident sexually transmitted diseases (STDs). High frequency of condom use showed a significant (P < .001) protective effect for HIV-1 incidence among men with a history of recent sex with female CSWs in univariate analysis, but a multivariate model demonstrated no difference in HIV-1 seroconversion rates by consistency of condom use. Multivariate analysis incorporating condom use showed that having sex with men (adjusted relative risk [RR], 2.59; 95% confidence interval [CI], 1.08 to 6.25), having sex with CSWs (adjusted RR ranged from 2.54 [95% CI, 1.81 to 3.58] to 2.74 [95% CI, 1.56 to 4.81]), and incident STDs (adjusted RR, 2.38 [95%, CI, 1.31 to 4.32]) to be predictors of incident HIV-1 infection. Substance use was not associated with HIV-1 seroconversion rates in multivariate analysis. The HIV-1 incidence in this cohort of young men appears to be primarily attributable to having sex with female CSWs. Condom use provided some protection, although not in multivariate analysis; however, condom use has previously been shown likely to be useful in preventing HIV-1 transmission. Thus, programs to increase effective condom use in brothels are essential. Efforts to extend condom use to non-CSW partners are especially needed. More effective prevention and treatment of STDs may also be necessary to decrease HIV-1 infection in this population.

Dynamics of Risk Behavior for HIV Infection Among Young Thai Men

The objective of this investigation was to analyze the dynamics of risk for HIV-1 infection among young men in Thailand. We conducted a prospective study in a cohort (n = 1,236) of young men, aged 19-23 years at conscription into the Royal Thai Army and Air Force from six provinces in northern Thailand in May 1991 who were followed until their discharge in April 1993. The outcome measure was change since conscription in the frequency of self-reported sex with female commercial sex workers (CSW) during military service. Although 42% of conscripts reported no visit to a female CSW in the year prior to conscription, most had a visit during military service. Men who visited female CSWs infrequently at baseline increased their visits somewhat over time, whereas those with high initial rates of CSW visits decreased. Based on an assumed stable distribution over time, change from baseline was not statistically significant. Only marital status and high baseline CSW visit rates were associated with diminished visit frequency in multivariate analysis. No differences were seen in patterns of change in CSW visits by HIV-1 serostatus. More aggressive preventive interventions are needed to reduce the frequency of CSW visits in northern Thailand, a setting where 40-80% of all female CSWs working in brothels are now HIV seropositive.

Willingness to participate in AIDS vaccine trials among high-risk populations in northern Thailand.

To determine the anticipated participation in a prophylactic AIDS vaccine trial and to identify perceived benefits and barriers to enrollment of HIV-seronegative volunteers at risk of HIV infection in northern Thailand. A cross-sectional survey. Subjects interviewed in a cross-sectional survey included female commercial sex workers (n = 215), men attending sexually transmitted disease clinics (n = 219), conscripts in the Royal Thai Army (n = 1453), and men discharged from the army (n = 293) who had returned to civilian life. We determined AIDS vaccine knowledge and attitudes, perceived vulnerability to HIV infection, barriers and incentives to participate in a future vaccine trial and agreement to participate in a randomized trial. Awareness of vaccines (88-97%) and AIDS vaccine development efforts (62-77%) were common and viewed to be a complement to behavior change (74-94%). Approximately 25% of subjects would definitely join a trial if asked, and an additional 38% would accept an AIDS vaccine if they were convinced it would be safe and effective. Important barriers to participation included concerns with discrimination (16-45%), short- (37-60%) and long-term (30-55%) vaccine side-effects, fear of disability and death (36-58%), and beliefs that partners would refuse to have sex (24-49%) after immunization. The principal inducement to join a trial was health insurance (62%). Potential HIV vaccine trial participants have several fears of joining a vaccine study at this time. Information derived from Phase I/II trials is needed to address these concerns if enrollment in efficacy trials is to be successful in the near future.

Declining prevalence of HIV-1 infection in young Thai men.

To evaluate trends in HIV-1 seroprevalence in Thailand. HIV-1 serosurvey of successive cohorts of young Thai men entering service with the Royal Thai Army (RTA) between November 1989 and November 1994. In November 1989, the RTA Medical Department began routine HIV-1-antibody screening of men who were selected by lottery for conscription. Between November 1989 and November 1994, 311,108 young men were screened at induction. Demographic data were collected between November 1991 and May 1993 and again in November 1994. The seroprevalence of HIV-1 among conscripts nationwide increased rapidly from 0.5% in 1989 to 3.5% in 1992 and reached 3.7% in 1993. In 1994, the overall prevalence decreased to 3.0%. The decrease was greatest in the upper North (from 12.4% in 1992 to 7.9% in 1994), where the prevalence has been the highest. However, decreases were observed in men from all regions of residence in the country, from both rural and urban areas, and at all educational levels. The decline in prevalence suggests declining incidence and that HIV control programs in Thailand are having an impact on the HIV epidemic.