HIV In Thailand Research Articles

Participating in HIV Clinical Trials: Reasons and Experiences Among Women Living With HIV in Thailand

The authors discuss the experiences of participating in HIV trials and their ethical concerns among Thai women living with HIV/AIDS. In-depth interviews and participant observations were conducted with 26 Thai women. Due to their vulnerability and poverty, HIV trials were particularly attractive to these women. Reasons included personal protection from infection, personal gains (free medication, medical care, and information about the development of future clinical trials), and social altruism. The attempts of the women to stay healthy and live longer by participating in clinical trials can be seen as health-promoting behavior. Participation in clinical trials helped to create a sense of optimism to combat the HIV epidemic. The participation also assisted the women to sustain the equilibrium of their emotional well-being. These findings can be valuable for the design and conduct of future HIV clinical trials and the provision of sensitive HIV care for women who are the vulnerable members of society.

Factors associated with high rates of antiretroviral medication adherence among youth living with perinatal HIV in Thailand.

Antiretroviral medication adherence behaviour among Thai youth with perinatal HIV in Thailand has received growing attention. However, few studies have examined individual predictors of antiretroviral adherence using multiple self-reports. A convenience sample of 89 Thai youth (interquartile range 14-16 years) with perinatal HIV at three paediatric programmes in Chiang Mai completed a structured questionnaire and reported their antiretroviral adherence in the past one, seven and 30 days using count-based recall and a visual analog scale. Mean self-reported adherence rates ranged from 83.5% (past 30 days) to 99.8% (yesterday) of the time. One-inflated beta regression models were used to examine the associations between antiretroviral adherence outcomes, treatment self-efficacy, depression, anxiety, social support and beliefs/attitudes about medications. Higher percentage of medications taken in the past 30 days was independently associated with higher treatment self-efficacy and fewer symptoms of depression. Adherence monitoring would benefit from focal assessment of youth depression and perceived capacity to follow their antiretroviral regimen.

The rapidly expanding CRF01_AE epidemic in China is driven by multiple lineages of HIV-1 viruses introduced in the 1990s

Objectives:We sought to comprehensively analyze the origin, transmission patterns and sub-epidemic clusters of the HIV-1 CRF01_AE strains in China.Methods:Available HIV-1 CRF01_AE samples indentified in national molecular epidemiologic surveys were used to generate near full-length genome (NFLG) sequences. The new and globally available CRF01_AE NFLG sequences were subjected to phylogenetic and Bayesian molecular clock analyses, and combined with epidemiologic data to elucidate the history of CRF01_AE transmission in China.Results:We generated 75 new CRF01_AE NFLG sequences from various risk populations covering all major CRF01_AE epidemic regions in China. Seven distinct phylogenetic clusters of CRF01_AE were identified. Clusters 1, 2 and 3 were prevalent among heterosexuals and IDUs in southern and southwestern provinces. Clusters 4 and 5 were found primarily among MSM in major northern cities. Clusters 6 and 7 were only detected among heterosexuals in two southeast and southwest provinces. Molecular clock analysis indicated that all CRF01_AE clusters were introduced from Southeast Asia in the 1990s, coinciding with the peak of Thailand's HIV epidemic and the initiation of China's free overseas travel policy for their citizens, which started with Thailand as the first destination country.Conclusion:China's HIV-1 epidemic of sexual transmissions, was initiated by multilineages of CRF01_AE strains, in contrast to the mono-lineage epidemic of B′ strain in former plasma donors and IDUs. Our study underscores the difficulty in controlling HIV-1 sexual transmission compared with parenteral transmission.

A Nursing Intervention to Enhance the Self-Care Capacity of Nondisclosed Persons Living With HIV in Thailand

Significant numbers of nondisclosed persons living with HIV (NPLWH) who are aware of their status do not enter care and must rely on their own abilities to maintain their health. This study shows how these individuals can be reached through nongovernmental organizations and assisted to improve their self-care capacity through an intensive nursing intervention. NPLWH in Chiang Mai, Thailand, were assessed using a 31-item self-care capacity questionnaire (range = 0-62) at baseline and monthly for 6 months. The nursing intervention used reflective questioning to assist PLWH to find ways to improve their self-care capacity. At baseline, the mean self-care capacity score was 31.4. After 3 months of intervention, the score increased to 54 and was maintained at this level for the next 3 months. This study demonstrates that nurses can reach out to NPLWH who are not in care and help to improve self-care capacity.

Prevalence of human leukocyte antigen-B*5701 among HIV-infected children in Thailand and Cambodia: implications for abacavir use.

Human leukocyte antigen (HLA)-B*5701 allele is associated with abacavir hypersensitivity. Limited data among Asians showed lower rates of HLA-B*5701 compared with Caucasians. In 296 children with HIV in Thailand and Cambodia, the prevalence of HLA-B*5701 was 4.0% (95% confidence interval: 1.6-8.0%) among Thai and 3.4% (95% confidence interval: 0.9-8.5%) among Cambodian children. HLA-B*5701 carriage is not uncommon among Thai and Cambodian children; it is close to the prevalence found in European and higher than the prevalence found in East Asian and African studies.

Motivational Interviewing Targeting Risk Behaviors for Youth Living with HIV in Thailand

Healthy Choices, a four-session motivational interviewing-based intervention, reduces risk behaviors among US youth living with HIV (YLWH). We randomized 110 Thai YLWH (16-25 years) to receive either Healthy Choices or time-matched health education (Control) over 12 weeks. Risk behaviors were assessed at baseline, 1, and 6 months post-session. The pilot study was not powered for between-group differences; there were no statistical differences in sexual risks, alcohol use, and antiretroviral adherence between the two groups at any visit. In within-group analyses, Healthy Choices group demonstrated decreases in the proportion of HIV-negative partners (20 vs 8.2%, P = 0.03) and HIV sexual risk scores (4.3 vs 3.3, P = 0.04), and increased trends in the proportion of protected sex (57 vs 76.3%, P = 0.07) from baseline to 1 month post-session. These changes were not sustained 6 months later. No changes were observed in Control group. Healthy Choices has potential to improve sexual risks among Thai YLWH.

Pregnant women and disclosure to sexual partners after testing HIV-1-seropositive during antenatal care.

In African countries highly affected by human immunodeficiency virus-1 (HIV-1) women are more likely to be tested for HIV-1 than men due to scale-up of antenatal testing programs to prevent mother-to-child transmission (PMTCT) of HIV-1. As part of standard post-test counseling HIV-1 seropositive women are advices to disclose their status to their partners and refer them for testing. Disclosure to male partners antenatally has been associated with improved adherence to prevention of PMTCT regimens better infant feeding practices safer sex practices and increase male partner testing. Despite these findings promotion of male partner disclosure is not a central component of most PMTCT programs. While barriers to female-to-male disclosure are well-described and include socio-economic vulnerability fear of violence of abandonment and family stigma little has been published describing how to promote disclosure to male partners after antenatal testing. This study followed Kenyan HIV-1 – seropositive women enrolled in a randomized clinical trial of herpes suppression during pregnancy until 1 year postpartum to determine disclosure rates and to assess timing and correlates of disclosure. Our hypothesis was that women who were counseled and supported to disclose their HIV-1 status as part of a longitudinal research study would over time be more likely to disclose to partners. There is clear evidence that promoting disclosure to partners in the antenatal setting can lead to both individual and public health benefits but little is known about how to achieve this goal. The research indicates that rather than focusing on strategies that focus on strategies that promote disclosure by women such as counseling there should be an emphasis on strategies that make HIV-1 testing more appealing to men in this setting such as shifts in infrastructure promoting ease and availability of testing and reduction of stigma and barriers to male partner HIV-1 testing and treatment. In conclusion the research shows that mothers diagnosed with HIV-1 antenatally face challenges in disclosing to their male partners.

Undertreatment of Pain in HIV+ Adults in Thailand

ContextChronic pain remains prevalent in HIV+ adults despite widespread antiretroviral use. Pain continues to be underrecognized and undertreated in this population. In Thailand, similar to the West, HIV care is transitioning toward chronic disease management. Despite the importance of pain management in chronic HIV, the prevalence of pain and adequacy of pain management is unknown in HIV+ adults in Thailand. ObjectivesThis cross-sectional study aimed to determine the prevalence of chronic pain, the burden of inadequate analgesia, and risk factors for chronic pain in HIV+ adults in Thailand. MethodsA total of 254 HIV+ adults were recruited from an outpatient clinic in Thailand. Interviewers obtained information on demographics, clinical data, and pain characteristics. The burden of inadequate analgesia was assessed using the Brief Pain Inventory. Risk factors were identified with logistic regression analysis. ResultsFrequent pain was reported by 27% of participants; 22% reported chronic pain. Pain was significantly associated with education less than primary school, a positive depression screen, and the number of years on combined antiretroviral therapy. Eighty-six percent of patients with frequent pain were inadequately treated. Of 34 patients with moderate or severe pain, none received adequate analgesia. Inadequate analgesia was a significant risk factor for poorer quality of life. ConclusionDespite widespread antiretroviral use, pain remains common and undertreated in HIV+ adults in Thailand. Undertreated pain negatively impacts quality of life. It is imperative that policy makers and HIV caregivers address this treatment gap to advance the care of people living with HIV in Thailand.

Health Related Quality of Life among Patients with Tuberculosis and HIV in Thailand

IntroductionHealth utilities of tuberculosis (TB) patients may be diminished by side effects from medication, prolonged treatment duration, physical effects of the disease itself, and social stigma attached to the disease.MethodsWe collected health utility data from Thai patients who were on TB treatment or had been successfully treated for TB for the purpose of economic modeling. Structured questionnaire and EuroQol (EQ-5D) and EuroQol visual analog scale (EQ-VAS) instruments were used as data collection tools. We compared utility of patients with two co-morbidities calculated using multiplicative model (UCAL) with the direct measures and fitted Tobit regression models to examine factors predictive of health utility and to assess difference in health utilities of patients in various medical conditions.ResultsOf 222 patients analyzed, 138 (62%) were male; median age at enrollment was 40 years (interquartile range [IQR], 35–47). Median monthly household income was 6,000 Baht (187 US$; IQR, 4,000–15,000 Baht [125–469 US$]). Concordance correlation coefficient between utilities measured using EQ-5D and EQ-VAS (UEQ-5D and UVAS, respectively) was 0.6. UCAL for HIV-infected TB patients was statistically different from the measured UEQ-5D (p-value<0.01) and UVAS (p-value<0.01). In tobit regression analysis, factors independently predictive of UEQ-5D included age and monthly household income. Patients aged ≥40 years old rated UEQ-5D significantly lower than younger persons. Higher UEQ-5D was significantly associated with higher monthly household income in a dose response fashion. The median UEQ-5D was highest among patients who had been successfully treated for TB and lowest among multi-drug resistant TB (MDR-TB) patients who were on treatment.ConclusionsUCAL of patients with two co-morbidities overestimated the measured utilities, warranting further research of how best to estimate utilities of patients with such conditions. TB and MDR-TB treatments impacted on patients' self perceived health status. This effect diminished after successful treatment.

Efficacy of an Intervention for Families Living with HIV in Thailand: A Randomized Controlled Trial

This study evaluates the efficacy of an intervention for persons living with HIV (PLH) and their family members in Thailand. A randomized controlled trial of 813 PLH and family members was carried out at four district hospitals in Thailand. Participants completed Computer Assisted Personal Interview assessments at baseline, 6, 12, 18, and 24 months. The primary outcome was quality of life (QoL); other measures included depressive symptoms and family functioning. Relative to the standard care condition, the intervention group reported significantly improved QoL at 6 months (P = 0.0014). When the intervention efficacy was stratified by baseline depressive symptoms (low vs. high), intervention efficacy was observed only among those with low depressive symptoms. Study findings suggest that the intervention was more efficacious for participants with less depressive symptoms and better family functioning. Extensive interventions may be optimal for those who have the capacity to learn the tools and skills.

The potential impact of an HIV vaccine with limited protection on HIV incidence in Thailand: A modeling study

Background The RV144 trial on the ALVAC/AIDSVAX candidate HIV vaccine, carried out in Thailand, showed short-lived protection against infection. Methods Using a deterministic compartmental model we explored the potential impact of this vaccine on heterosexual HIV transmission in Thailand. Both one-off vaccination strategies, as well as strategies with regular boosting, either annually or every two years, were explored. Both targeting the general adult population and prioritizing sex workers were modeled. The impact of risk compensation among high risk groups, as well as whether higher levels of safe sex in high risk groups could be an alternative to vaccination, was studied. Results One-off vaccination campaigns had only transient effects, and boosting appears to be a key component of successful vaccination campaigns. Intensive vaccination campaigns may reduce HIV incidence by up to 75% after 10 years of vaccination. Targeting only sex workers has a smaller impact but has a more favorable cost–benefit ratio. Risk compensation has the potential of undoing much of the benefits of a vaccination program and may even increase incidence. In contrast, higher levels of safe sex among sex workers would provide a viable alternative to vaccinating this group. Discussion The new vaccine holds promise for controlling HIV in Thailand and similar countries. In view of the short lived protection of the vaccine, regular boosting of immunity as well as avoidance of risk compensation are essential. Targeting sex workers would achieve the greatest reduction in incidence per vaccination and may be considered for expensive vaccines but its cost-effectiveness has to be compared to alternatives.

Improving the Health and Mental Health of People Living With HIV/AIDS: 12-Month Assessment of a Behavioral Intervention in Thailand

We examined findings from a randomized controlled intervention trial designed to improve the quality of life of people living with HIV in Thailand. A total of 507 people living with HIV were recruited from 4 district hospitals in northern and northeastern Thailand and were randomized to an intervention group (n = 260) or a standard care group (n = 247). Computer-assisted personal interviews were administered at baseline and at 6 and 12 months. At baseline, the characteristics of participants in the intervention and standard care conditions were comparable. The mixed-effects models used to assess the impact of the intervention revealed significant improvements in general health (B = 2.51; P = .001) and mental health (B = 1.57; P = .02) among participants in the intervention condition over 12 months and declines among those in the standard care condition. Our results demonstrate that a behavioral intervention was successful in improving the quality of life of people living with HIV. Such interventions must be performed in a systematic, collaborative manner to ensure their cultural relevance, sustainability, and overall success.

Effects of CYP2B6 G516T polymorphisms on plasma efavirenz and nevirapine levels when co-administered with rifampicin in HIV/TB co-infected Thai adults

BackgroundCytochrome P450 2B6 (CYP2B6) metabolizes efavirenz and nevirapine, the major core antiretroviral drugs for HIV in Thailand. Rifampicin, a critical component of tuberculosis (TB) therapy is a potent inducer of CYP enzyme activity. Polymorphisms of CYP2B6 and CYP3A4 are associated with altered activity of hepatic enzyme in the liver and pharmacokinetics resulting in treatment efficacy. This study aimed to investigate whether CYP2B6 or CYP3A4 polymorphisms had effects on plasma efavirenz and nevirapine concentrations when co-administered with rifampicin in HIV/TB co-infected Thai adults.ResultsWe studied 124 rifampicin recipients with concurrent HIV-1/TB coinfection, receiving efavirenz (600 mg/day) (n = 65) or nevirapine (400 mg/day) (n = 59) based antiretroviral therapy (ART). The frequencies of GG, GT and TT genotypes of CYP2B6-G516T were 38.46%, 47.69% and 13.85% in efavirenz group and 44.07%, 52.54% and 3.39% in nevirapine group, respectively. The mean 12-hour post-dose plasma efavirenz concentration in patients with TT genotype at weeks 6 and 12 of ART and 1 month after rifampicin discontinuation (10.97 ± 2.32, 13.62 ± 4.21 and 8.48 ± 1.30 mg/L, respectively) were significantly higher than those with GT (3.43 ± 0.29, 3.35 ± 0.27 and 3.21 ± 0.22 mg/L, respectively) (p < 0.0001) or GG genotypes (2.88 ± 0.33, 2.45 ± 0.26 and 2.08 ± 0.16 mg/L, respectively) (p < 0.0001). Likewise, the mean 12-hour post-dose plasma nevirapine concentration in patients carrying TT genotype at weeks 6 and 12 of ART and 1 month after rifampicin discontinuation (14.09 ± 9.49, 7.94 ± 2.76 and 9.44 ± 0.17 mg/L, respectively) tended to be higher than those carrying GT (5.65 ± 0.54, 5.58 ± 0.48 and 7.03 ± 0.64 mg/L, respectively) or GG genotypes (5.42 ± 0.48, 5.34 ± 0.50 and 6.43 ± 0.64 mg/L, respectively) (p = 0.003, p = 0.409 and p = 0.448, respectively). Compared with the effects of CYP2B6-516TT genotype, we could observe only small effects of rifampicin on plasma efavirenz and nevirapine levels. After 12 weeks of both drug regimens, there was a trend towards higher percentage of patients with CYP2B6-TT genotype who achieved HIV-1 RNA levels <50 copies/mL compared to those with GT or GG genotypes. This is the first report to demonstrate the effects of CYP2B6 G516T polymorphisms on plasma efavirenz and nevirapine concentrations when co-administered with rifampicin in HIV/TB co-infected Thai adults.ConclusionsCYP2B6-TT genotype had impact on plasma efavirenz and nevirapine concentrations, while rifampicin co-administration had only small effects.

Caregiver burden of family members of persons living with HIV in Thailand

Caregivers of people living with HIV (PLH) in Thailand face tremendous caregiver burden. This study examines complex ways in which caregivers' mental health affects their levels of caregiver burden. This study uses data from 409 caregivers of PLH in northern and north-eastern Thailand. Multiple regression models were used to examine the predictors of caregiver burden. Depression was significantly associated with caregiver burden (P < 0.0001) and being HIV positive (P = 0.015). Inverse associations were observed between depression and quality of life (P < 0.0001) and caregiver burden and quality of life (P = 0.004). Social support had direct positive association with caregiver's quality of life (P < 0.0001). Our findings underscore the complex relationship between caregiver burden, depression and HIV-status. Interventions that address the caregiver burden are urgently needed.

Stigma, social support, and depression among people living with HIV in Thailand

Background. People living with HIV/AIDS (PLWHA) in Thailand face tremendous challenges, including HIV-related stigma, lack of social support, and mental health issues such as depression. This study aims to examine complex relationships among demographics, HIV-related stigma, and social support and their impact on depression among PLWHA in Thailand. Methods. This study uses data collected in northern and northeastern Thailand. A total of 408 PLWHA were recruited and interviewed in 2007. HIV-related stigma was measured by two subscales: “Internalized Shame” and “Perceived Stigma.” Based on correlation analyses, hierarchical multiple regression models were used to examine the predictors of depression, social support, and HIV-related stigma, controlling for demographic characteristics. Results. Correlational analysis revealed that depression was significantly associated with both dimensions of stigma: internalized shame and perceived stigma. Self-reported emotional social support was negatively associated with depression. We found that internalized shame and emotional social support were significant predictors of depression after controlling for gender, age, income, and education. Conclusions. HIV-related stigma has a negative impact on psychological wellbeing of PLWHA in Thailand, and emotional social support remains a protective factor against depression. Intervention developers and clinicians working with PLWHA may find it useful to incorporate the association between stigma and depression into their programs and treatments, and to address social support as a protective effect for the mental health of PLWHA.

Indicators for sexual HIV transmission risk among people in Thailand attending HIV care: the importance of positive prevention

Background:Almost half of all new HIV infections in Thailand occur among low-risk partners of people infected with HIV, so it is important to include people infected with HIV in prevention...

Respondent-driven sampling to assess characteristics and estimate the number of injection drug users in Bangkok, Thailand

Background Since early in Thailand's HIV epidemic, HIV seroprevalence among injection drug users (IDUs) in Bangkok has been around 40%. As Thailand moves to strengthen HIV prevention and care programs for Bangkok IDUs, information on current patterns of drug use and an estimate of the size and composition of the IDU population are essential. Methods We used respondent-driven sampling (RDS) to recruit Bangkok IDUs who reported injecting in the past 6 months. IDUs were interviewed with a standardized questionnaire. Logistic regression was used to compare IDUs currently or previously in treatment with those never treated. RDS software was used to estimate IDU population size based on the proportion in treatment. Results Of 963 IDUs recruited, 828 (86%) were men. One hundred and twelve IDUs (12%) reported never having attended a drug treatment clinic. Young age, unemployment, injection of single drug, and never having been HIV tested were significantly associated with never-in-treatment status. The estimated proportion of IDUs in treatment was 0.55 (95% confidence interval, 0.52–0.60). Dividing the known number of IDUs in treatment (1981 IDUs attending Bangkok drug treatment clinics during October 2003 through March 2004) by this proportion, we estimated the number of IDUs in Bangkok during the period of RDS to be 3595 (95% confidence interval, 3296–3810). Conclusions Data obtained through RDS, although subject to limitations from co-existing government drug control policies and possible under-recruitment of out-of-treatment IDUs, will be useful in informing policy, strengthening prevention approaches, and improving methods to monitor the HIV epidemic among Thai IDUs.

Reduction in mother-to-child transmission of HIV in Thailand, 2001–2003: results from population-based surveillance in six provinces

In 2000, Thailand implemented a national program to prevent mother-to-child HIV transmission (PMTCT). To describe the effectiveness of the prevention of mother-to-child HIV transmission program in Thailand. A register of HIV-exposed children at birth was created with follow-up of infection status. The register included children born to HIV-infected women between 1 January 2001 and 31 December 2003 at 84 public health hospitals in six provinces of Thailand. The main outcome measure was HIV infection in children. A total of 2200 children born to HIV-infected mothers were registered. Of these mother-infant pairs, 2105 (95.7%) received some antiretroviral prophylaxis, including 1358 (61.7%) who received the complete short-course zidovudine regimen during pregnancy and labor for the mother and after birth for the infant, with or without other antiretrovirals. HIV infection outcome was determined for 1667 (75.8%) children, of whom 158 [9.5%, 95% confidence interval (CI), 8.1-11.0%] were infected. Transmission risk was 6.8% (95% CI 5.2-8.9%) among 761 mother-infant pairs that received the complete zidovudine regimen alone, and 3.9% (95% CI, 2.2-6.6%) among 361 mother-infant pairs that received the complete zidovudine regimen combined with other antiretrovirals, usually nevirapine. The overall transmission risk from this cohort, including all antiretroviral prophylaxis combinations, is estimated to be 10.2%. The Thai national PMTCT program is effective in reducing mother-to-child transmission risk from the historical risk of 18.9-24.2%. The addition of nevirapine to short-course zidovudine beginning in 2004 may further improve program effectiveness in Thailand.

Living with HIV in Thailand: Assessing Vulnerability through a Life-Event History Approach

Living with HIV in Thailand: Assessing Vulnerability through a Life-Event History Approach

Living with HIV in Thailand: Assessing Vulnerability through a Life-Event History Approach

Thailand was the first Asian country to be affected by the AIDS epidemic in the late 1980s. It is one of the most hard-hit countries in the region and nearly one million people have been infected so far (World Bank, 2000). The epidemic first developed among intravenous drug users, and then among sex workers and their clients (Weniger et al., 1991). As the epidemic matured, heterosexual transmission became the major route of infection in the general population and the first cases of mother-to-child HIV transmission were reported in 1991 (World Bank, 2000). However, considerable efforts have been invested by the government to curtail the HIV/AIDS epidemic. The Royal Thai Government responded quickly and implemented a multi-sector AIDS programme in 1987. These efforts appear to have been successful in reducing not only the incidence of HIV in the general population but also the prevalence of other sexually transmitted diseases (Nelson et al., 1996; Hanenbert et al., 1994). The overall infection rate in pregnant women is now about 1.2% nationwide (Ministry of Public Health, 2004).Nevertheless, the number of AIDS cases will continue to increase for a number of years, reflecting earlier infection trends, while scaling up of antiretroviral treatment access will reduce the number of AIDS deaths. Although recent studies have shed light upon the epidemic's demographic, economic, public health and social impacts, the strategies adopted by the affected families and communities are still unknown (see Surasiengsunk et al., 1998; Knodel et al., 2001; VanLandingham et al., 2002; Knodel, Imem, 2002; Kespichayawattana, VanLandingham, 2003).HIV infection is closely linked to sexuality and reproductive health. It is a sexually transmitted infection, thus affecting both partners in a couple, and it is transmitted to their children, whose future is thereby placed in jeopardy. Although individual risk behaviours have been extensively studied in Thailand (Sittitrai et al., 1992; Nelson et al., 1993; Nagachinta, 1997; Beyrer et al., 1997) we still have very little knowledge of the circumstances or combination of circumstances which increase the risk of HIV infection (or protect against it) in an individual's life course.Almost all Thai women benefit during pregnancy from antenatal care which includes voluntary HIV counselling and testing. HIV screening is remarkably well-accepted, with a take-up rate of over 95% among pregnant women (Amornwichet, 2002; Koetsawang, 1999). Couple counselling and testing is also encouraged. In the event of a positive test result, the future mother receives free antiretroviral treatment to protect her child from infection via the national programme for the prevention of mother-to-child HIV transmission (Kanshana S, 2002). These young mothers are generally aware of their HIV status and they represent the closest available sample to the general population of reproductive age.To study the circumstances which increase the risk of HIV infection, we thought it would be useful to explore the notion of vulnerability, defined less in terms of epidemiological or risk factors than in relation to sociocultural, psychological and economic aspects. To identify vulnerable situations, we adopted a life event history perspective (Courgeau, Lelievre, 1992; Manton et al., 1992; Courgeau, Lelievre, 1996), through which individual life histories are considered as a continuum of events of different kinds relating to family, housing, occupation, health, etc., and affecting the dependent variable, i.e. vulnerability to HIV.In this short paper we assess the feasibility of a specific survey technique and sampling plan designed to serve these objectives, through a pilot survey conducted in Thailand in 2001(1).Different innovations were tested in the pilot survey: the collection of health histories combined with migration, family and occupational histories, the testing of case-control sampling more familiar to epidemiologists than demographers, and also the systematic interviewing of both partners within couples. …