Does BCG vaccination protect against infection with M. tuberculosis?

BACKGROUND: Protection against infection by the bacille Calmette-Guérin vaccine against Mycobacterium tuberculosis remains a subject of controversy. We investigated the association between BCG vaccination at birth and infection by M. tuberculosis.MATERIAL and METHODS: This was a secondary analysis of data from tuberculin skin test (TST) surveys in Vietnamese schoolchildren between 1988 and 2001. We investigated whether a BCG scar was associated with a lower prevalence of TST positivity, adjusting for BCG-induced variation by varying cut-off values for a positive TST.RESULTS: We found a positive association between BCG scar and TST positivity. The strength of the association decreased with increasing TST cut-off values; however, it never inverted significantly, irrespective of geographic region and survey year.CONCLUSION: In Vietnam, BCG vaccination was not associated with reduced M. tuberculosis infection prevalence as measured using TST. This in contrary to a similar study conducted in Tanzania. These contradictory findings may be explained by geographical differences and the relatively high prevalence in Vietnam of the M. tuberculosis Beijing genotype, which is reported to be capable of circumventing BCG-induced immunity.

Safety and immunogenicity of two formulations of rotavirus vaccine in Vietnamese infants.

BACKGROUND AND AIMS: ROTAVIN-M1® (licensed, frozen vaccine) and ROTAVIN (second-generation, liquid candidate vaccine) are two rotavirus vaccine formulations developed from a live attenuated G1P8 (KH0118) strain by Center for Research and Production of Vaccines and Biologicals (POLYVAC), Vietnam. This study compared the safety and immunogenicity of these two formulations. METHODS: A Phase 3, randomized, partially double-blinded, active-controlled study was conducted in healthy infants aged 60-91 days in Vietnam. Infants received two doses of ROTAVIN or ROTAVIN-M1 in a ratio of 2:1 with an interval of 8 weeks. Solicited reactions were collected for 7 days after each vaccination. Blood samples were collected pre-vaccination and 4 weeks after the second vaccination in a subset of infants. Non-inferiority criteria required that the lower bound of 95% confidence intervals (CIs) of the post-vaccination anti-rotavirus IgA GMC (Geometric Mean Concentration) ratio of ROTAVIN/ROTAVIN-M1 should be >0.5. A co-primary objective was to compare the safety of the two vaccines in terms of solicited reactions. RESULTS: A total of 825 infants were enrolled. The post-vaccination GMC was 48.25 (95% CI: 40.59, 57.37) in the ROTAVIN group and 35.04 (95% CI: 27.34, 44.91) in the ROTAVIN-M1 group with an IgA GMC ratio of 1.38 (95% CI: 1.02, 1.86) thus meeting the pre-set criteria for non-inferiority. A total of 605 solicited reactions were reported in 297 (36.0%) participants with 35.4% in the ROTAVIN group and 37.2% in the ROTAVIN-M1 group. There were no cases of intussusception or death reported in the study. CONCLUSIONS: Based on the data generated, it can be concluded that ROTAVIN is immunologically non-inferior and has similar safety profile to ROTAVIN-M1 when administered to infants in a two-dose schedule. Therefore, it can be considered as a more suitable option for programmatic use to prevent rotavirus diarrhoea in Vietnam and the Mekong region. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov identifier: NCT03703336, October 11, 2018.

Confirmed archaeological evidence of water deer in Vietnam: relics of the Pleistocene or a shifting baseline?

Studies of archaeological and palaeontological bone assemblages increasingly show that the historical distributions of many mammal species are unrepresentative of their longer-term geographical ranges in the Quaternary. Consequently, the geographical and ecological scope of potential conservation efforts may be inappropriately narrow. Here, we consider a case-in-point, the water deer Hydropotes inermis, which has historical native distributions in eastern China and the Korean peninsula. We present morphological and metric criteria for the taxonomic diagnosis of mandibles and maxillary canine fragments from Hang Thung Binh 1 cave in Tràng An World Heritage Site, which confirm the prehistoric presence of water deer in Vietnam. Dated to between 13 000 and 16 000 years before the present, the specimens are further evidence of a wider Quaternary distribution for these Vulnerable cervids, are valuable additions to a sparse Pleistocene fossil record and confirm water deer as a component of the Upper Pleistocene fauna of northern Vietnam. Palaeoenvironmental proxies suggest that the Tràng An water deer occupied cooler, but not necessarily drier, conditions than today. We consider if the specimens represent extirpated Pleistocene populations or indicate a previously unrecognized, longer-standing southerly distribution with possible implications for the conservation of the species in the future.

Institutionalising wastewater surveillance systems to minimise the impact of COVID-19: cases of Indonesia, Japan and Viet Nam.

This mini review describes the current status and challenges regarding institutionalisation of wastewater surveillance systems against COVID-19. Monitoring SARS-CoV-2 in wastewater has been proposed to be a potential tool to understand the actual prevalence of COVID-19 in the community, and it could be an effective approach to monitor the trend during the COVID-19 pandemic. However, challenges to institutionalise wastewater surveillance systems are still abundant and unfolding at a rapid rate given that the international understanding regarding the scientific knowledge and socio-political impacts of COVID-19 are in the developing stages. To better understand the existing challenges and bottlenecks, a comparative study between Japan, Viet Nam, and Indonesia was carried out in the present study. Through gaining a better understanding of common issues as well as issues specific to each country, we hope to contribute to building a robust multistakeholder system to monitor SARS-CoV-2 in wastewater as an effective disease surveillance system for COVID-19.

An 11 000-year-old giant muntjac subfossil from Northern Vietnam: implications for past and present populations.

Described at the end of the twentieth century, the large-antlered or giant muntjac, Muntiacus gigas (syn. vuquangensis), is a Critically Endangered species currently restricted to the Annamite region in Southeast Asia. Here we report subfossil evidence of giant muntjac, a mandible fragment dated between 11.1 and 11.4 thousand years before present, from northern Vietnam. We describe morphological and metric criteria for diagnosis and consider the specimen in the context of regional archaeological and palaeontological records of Muntiacus. We then consider the palaeoenvironmental context of the specimen and the implications for habitat requirements for extant populations. The new specimen extends the known spatial and temporal range of giant muntjacs in Vietnam and is further evidence that this species was more widely distributed in the Holocene than current records indicate. While regional proxy evidence indicates a drier climate and more open woodland habitats at the onset of the Holocene, contextual evidence indicates that the specimen derived from an animal inhabiting limestone karst forest. This record also supports the assertion that remnant populations are in a refugial state, as a result of anthropogenic pressures, rather than representing a centre of endemism. These facts underscore the urgent need for the conservation of remaining populations.

Establishing and validating noninvasive prenatal testing procedure for fetal aneuploidies in Vietnam.

Objective: Noninvasive prenatal testing (NIPT) for fetal aneuploidies has been widely adopted in developed countries. Despite the sharp decrease in the cost of massively parallel sequencing, the technical know-how and skilled personnel are still one of the major limiting factors for applying this technology to NIPT in low-income settings. Here, we present the establishment and validation of our NIPT procedure called triSure for detection of fetal aneuploidies. Methods: We established the triSure algorithm based on the difference in proportion of fetal and maternal fragments from the target chromosome to all chromosomes. Our algorithm was validated using a published data set and an in-house data set obtained from high-risk pregnant women in Vietnam who have undergone amniotic testing. Several other aneuploidy calling methods were also applied to the same data set to benchmark triSure performance. Results: The triSure algorithm showed similar accuracy to size-based method when comparing them using published data set. Using our in-house data set from 130 consecutive samples, we showed that triSure correctly identified the most samples (overall sensitivity and specificity of 0.983 and 0.986, respectively) compared to other methods tested including count-based, sized-based, RAPIDR and NIPTeR. Conclusions: We have demonstrated that our triSure NIPT procedure can be applied to pregnant women in low-income settings such as Vietnam, providing low-risk screening option to reduce the need for invasive diagnostic tests.

Comparative satisfaction of receiving medical abortion service from nurses and auxiliary nurse-midwives or doctors in Nepal: results of a randomized trial.

BACKGROUND: Early first-trimester medical abortion (MA) service (≤ 63 days) has been provided by doctors and nurses under doctors' supervision since 2009 in Nepal. This paper assesses whether MA services provided by specifically trained and certified nurses and auxiliary nurse-midwives independently from doctors' supervision, is considered as satisfactory by women as those provided by doctors. METHODS: The data come from a multi-center, randomized, controlled equivalence trial conducted between April 2009 and March 2010 in five district hospitals in Nepal. Women seeking MA were randomly assigned to doctors or nurses and auxiliary nurse-midwives(ANMs).Eligible women were administered 200 mg mifepristone orally followed by 800 µg misoprostol vaginally two days later by their assigned providers and followed up 10-14 days later. At the follow-up visit women's reported satisfaction with MA service they received was measured. RESULTS: Of 1295 women screened for eligibility, 535 were randomly assigned to a doctor and 542 to a nurse or ANM. Nineteen women were lost-to-follow up in the former group and 27 were lost-to-follow up or did not complete the acceptability interview in the latter group. This study is, therefore, based on516womenin the doctor's group and 515 women in the nurse or ANM group. All women in the nurse or ANM group reported being satisfied or highly satisfied by MA compared to 99% in the doctor's group. Satisfaction was similar regardless of the type of provider; 38% among nurse or ANM and 35% among the doctor group were "highly satisfied", and 62% and 64%, respectively, were "satisfied". Women's experiences such as 'less than expected amount or duration of bleeding following MA', 'shorter than expected duration of the abortion process', and 'able to manage symptoms', were found to be associated with women's higher satisfaction with MA. Counseling and information on the method, potential complications of MA and post-abortion contraception was nearly universal. No statistically significant differences were found in the level of satisfaction by age, parity, marital status, education or occupation of women. CONCLUSIONS: Women's satisfaction with MA service provided by trained nurses or auxiliary nurse-midwives was similar to that provided by doctors. The findings, therefore, provide support for extending safe and accessible medical abortion services by government-trained nurses and auxiliary nurse midwives to women seeking early first trimester pregnancy termination. TRIAL REGISTRATION: The trial was retrospectively registered with ClinicalTrials.gov (identifier: NCT01186302 ). Registered August 20, 2010.

A cluster randomized controlled trial of the non-pneumatic anti-shock garment for obstetric haemorrhage: sub-analysis of the Zimbabwean Arm.

Objectives: To determine whether earlier application of the Non-pneumatic Anti-Shock Garment (NASG) at clinic level compared to the referral hospital level reduces maternal morbidity and mortality and recovery time from shock due to severe Obstetric Haemorrhage (OH) and to determine the safety of the NASG when applied at clinic level. Design: A cluster Randomized Controlled Trial (RCT) Setting: Harare and Parirenyatwa Referral Hospitals (RH) in Harare and the twelve Harare City Council clinics that offer maternity care. Subjects: Women who had suffered severe OH at clinic level and were being transferred to a Referral Hospital (RH). Iterventions: The clinics were randomized into two groups. In the early NASG group eligible women were given the standard management for OH and had the NASG applied at the clinic level before transport to RH. In the control group, eligible women were given the standard management for OH at the clinic level, transferred to the RH, and received the NASG at the RH. All women received equivalent OH/hypovolemic shock management at the RH. Main Outcome Measures: The main outcome measures were maternal mortality and morbidity, blood loss, recovery from shock and the occurrence of side effects whilst in the NASG. Results: There were few maternal deaths and morbidities, and no statistically significant differences between the two groups were noted. Women in the early NASG group spent a statistically significant shorter time in the NASG at referral hospital level (OR 0.64, 95% CI 0.52 - 0.79, p < 0.001) and had a non-significant 40% faster recovery from shock (HR 1.39; 95% CI 0.98-1.97, p=0.07). There were no differences in reported side effects. Conclusion: Earlier NASG application at the clinic level was associated with faster recovery from shock in women who had suffered severe OH and appears safe to use.

Non-pneumatic anti-shock garment (NASG), a first-aid device to decrease maternal mortality from obstetric hemorrhage: a cluster randomized trial.

BACKGROUND: Obstetric hemorrhage is the leading cause of maternal mortality. Using a cluster randomized design, we investigated whether application of the Non-pneumatic Anti-Shock Garment (NASG) before transport to referral hospitals (RHs) from primary health care centers (PHCs) decreased adverse outcomes among women with hypovolemic shock. We hypothesized the NASG group would have a 50% reduction in adverse outcomes. METHODS AND FINDINGS: We randomly assigned 38 PHCs in Zambia and Zimbabwe to standard obstetric hemorrhage/shock protocols or the same protocols plus NASG prior to transport. All women received the NASG at the RH. The primary outcomes were maternal mortality; severe, end-organ failure maternal morbidity; and a composite mortality/morbidity outcome, which we labeled extreme adverse outcome (EAO). We also examined whether the NASG contributed to negative side effects and secondary outcomes. The sample size for statistical power was not reached; of a planned 2400 women, 880 were enrolled, 405 in the intervention group. The intervention was associated with a non-significant 46% reduced odds of mortality (OR 0.54, 95% CI 0.14-2.05, p = 0.37) and 54% reduction in composite EAO (OR 0.46, 95% CI 0.13-1.62, p = 0.22). Women with NASGs recovered from shock significantly faster (HR 1.25, 95% CI 1.02-1.52, p = 0.03). No differences were observed in secondary outcomes or negative effects. The main limitation was small sample size. CONCLUSIONS: Despite a lack of statistical significance, the 54% reduced odds of EAO and the significantly faster shock recovery suggest there might be treatment benefits from earlier application of the NASG for women experiencing delays obtaining definitive treatment for hypovolemic shock. As there are no other tools for shock management outside of referral facilities, and no safety issues found, consideration of NASGs as a temporizing measure during delays may be warranted. A pragmatic study with rigorous evaluation is suggested for further research. TRIAL REGISTRATION: ClinicalTrials.gov NCT00488462.

Acceptability of misoprostol-only medical termination of pregnancy compared with vacuum aspiration: an international, multicentre trial.

OBJECTIVE: To compare women's acceptance of misoprostol-only medical termination of pregnancy (TOP) with surgical TOP. DESIGN: Prospective cohort study. SETTING: Termination of pregnancy clinics in New Delhi, Mumbai, Hanoi, Tbilisi, Trivandrum and Yerevan. POPULATION: Women requesting TOP, at 63 days of gestation or less, at study sites where both medical and surgical methods were available. METHODS: Serial surveys eliciting measures of women's satisfaction and acceptance of TOP method were administered. Data were analysed using cross-tabulation and logistic regression to determine if TOP method was predictive of acceptability. MAIN OUTCOME MEASURES: Patient acceptance. RESULTS: High acceptability of both surgical and misoprostol-only TOP. CONCLUSIONS: Where medical TOP with mifepristone is not available, misoprostol-only medical TOP is acceptable to women who have the choice between medical or surgical techniques.

Can midlevel health-care providers administer early medical abortion as safely and effectively as doctors? A randomised controlled equivalence trial in Nepal.

BACKGROUND: Medical abortion is under-used in developing countries. We assessed whether early fi rst-trimester medical abortion provided by midlevel providers (government-trained, certified nurses and auxiliary nurse midwives) was as safe and effective as that provided by doctors in Nepal. METHODS: This multicentre randomised controlled equivalence trial was done in fi ve rural district hospitals in Nepal. Women were eligible for medical abortion if their pregnancy was of less than 9 weeks (63 days) and if they resided less than 90 min journey away from the study clinic. Women were ineligible if they had any contraindication to medical abortion. We used a computer-generated randomisation scheme stratified by study centre with a block size of six. Women were randomly assigned to a doctor or a midlevel provider for oral administration of 200 mg mifepristone followed by 800 µg misoprostol vaginally 2 days later, and followed up 10-4 days later. The primary endpoint was complete abortion without manual vacuum aspiration within 30 days of treatment. The study was not masked. Abortions were recorded as complete, incomplete, or failed (continuing pregnancy). Analyses for primary and secondary endpoints were by intention to treat, supplemented by per-protocol analysis of the primary endpoint. This trial is registered with ClinicalTrials.gov, NCT01186302. FINDINGS: Of 1295 women screened, 535 were randomly assigned to a doctor and 542 to a midlevel provider. 514 and 518, respectively, were included in the analyses of the primary endpoint. Abortions were judged complete in 504 (97.3%) women assigned to midlevel providers and in 494 (96.1%) assigned to physicians. The risk difference for complete abortion was 1.24% (95% CI -0.53 to 3.02), which falls within the predefined equivalence range (-5% to 5%). Five cases (1%) were recorded as failed abortion in the doctor cohort and none in the midlevel provider cohort; the remaining cases were recorded as incomplete abortions. No serious complications were noted. INTERPRETATION: The provision of medical abortion up to 9 weeks' gestation by midlevel providers and doctors was similar in safety and effectiveness. Where permitted by law, appropriately trained midlevel health-care providers can provide safe, low-technology medical abortion services for women independently from doctors. FUNDING: UNDP/UNFPA/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), Department of Reproductive Health and Research (RHR), World Health Organization.

Misoprostol dose and route after mifepristone for early medical abortion: a randomised controlled noninferiority trial.

OBJECTIVE: To compare 400 and 800 microg sublingual or vaginal misoprostol 24 hours after 200 mg mifepristone for noninferiority regarding efficacy in achieving complete abortion for pregnancy termination up to 63 days of gestation. DESIGN: Placebo-controlled, randomised, noninferiority factorial trial, stratified by centre and length of gestation. Misoprostol 400 or 800 microg, administered either sublingually or vaginally, with follow up after 2 and 6 weeks. SETTING: Fifteen obstetrics/gynaecology departments in ten countries. POPULATION: Pregnant women (n = 3005) up to 63 days of gestation requesting medical abortion. METHODS: Two-sided 95% CI for differences in failure of complete abortion and continuing pregnancy, with a 3% noninferiority margin, were calculated. Proportions of women with adverse effects were recorded. OUTCOME MEASURES: Complete abortion without surgical intervention (main); continuing live pregnancies, induction-to-abortion interval, adverse effects, women's perceptions (secondary). RESULTS: Efficacy outcomes analysed for 2962 women (98.6%): 90.5% had complete abortion after 400 microg misoprostol, 94.2% after 800 microg. Noninferiority of 400 microg misoprostol was not demonstrated for failure of complete abortion (difference: 3.7%; 95% CI 1.8-5.6%). The 400-microg dose showed higher risk of incomplete abortion (P < 0.01) and continuing pregnancy (P < 0.01) than 800 microg. Vaginal and sublingual routes had similar risks of failure to achieve complete abortion (P = 0.47, difference in sublingual minus vaginal -0.7%, 95% CI -2.6-1.2%). A similar pattern was observed for continuing pregnancies (P = 0.21). Fewer women reported adverse effects with vaginal than sublingual administration and with the 400-microg dose than the 800-microg dose. Of the women, 94% were satisfied or highly satisfied with the regimens, 53% preferred the sublingual route and 47% preferred the vaginal route. CONCLUSIONS: A 400-microg dose of misoprostol should not replace the 800-microg dose when administered 24 hours after 200 mg mifepristone for inducing abortion in pregnancies up to 63 days. Sublingual and vaginal misoprostol have similar efficacy, but vaginal administration is associated with a lower frequency of adverse effects.

Two mifepristone doses and two intervals of misoprostol administration for termination of early pregnancy: a randomised factorial controlled equivalence trial.

OBJECTIVE: To compare the efficacy of 100 mg and 200 mg of mifepristone and 24- and 48-hour intervals to administration of 800 microg vaginal misoprostol for termination of early pregnancy. DESIGN: Placebo-controlled, randomized, equivalence trial, stratified by centre. SETTING: 13 departments of obstetrics and gynecology in nine countries. POPULATION: 2,181 women with 63 days or less gestation requesting medical abortion. METHODS: Two-sided 95% CI for the risk differences of failure to complete abortion were calculated and compared with 5% equivalence margin between two doses of mifepristone and two intervals to misoprostol administration. Proportions of women with adverse effects were compared between the regimens using standard testes for proportions. OUTCOME MEASURES: Rates of complete abortion without surgical intervention and adverse effects associated with the regimens. RESULTS: Efficacy outcome was analysed for 2,126 women (97.5%) excluding 55 lost to follow up. Both mifepristone doses were found to be similar in efficacy. The rate of complete abortion was 92.0% for women assigned 100 mg of mifepristone and 93.2% for women assigned 200 mg of mifepristone (difference 1.2%, 95% CI: -1.0 to 3.5). Equivalence was also evident for the two intervals of administration: the rate of complete abortion was 93.5% for 24-hour interval and 91.7% for the 48-hour interval (difference -1.8%, 95% CI: -4.0 to 0.5). Interaction between doses and interval to misoprostol administration was not significant (P = 0.92). Adverse effects related to treatments did not differ between the groups. CONCLUSIONS: Both the 100 and 200 mg doses of mifepristone and the 24- and 48-hour intervals have a similar efficacy to achieve complete abortion in early pregnancy when mifepristone is followed by 800 micrograms of vaginally administered misoprostol.

Management training in Vietnam's National Tuberculosis Program: an impact evaluation.

SETTING: National Tuberculosis Program (NTP), Vietnam. OBJECTIVES: To show how the Sustainable Management Development Program (SMDP) of the US Centers for Disease Control and Prevention created capacity within Vietnam's NTP to organize a management training program, and to assess the influence of the NTP's in-country training program on individual and team management practices and the performance of provincial TB control programs. DESIGN: Eight case studies of participating provincial TB organizations, including cross-case and content analysis. RESULTS: Participants and their back-home learning project teams demonstrated a solid understanding of the concepts taught, particularly evidence-based decision making, problem diagnosis and problem solving, and using teamwork to improve results. They gave multiple examples of how they use these concepts in their daily work. Project teams exceeded, attained or very nearly attained their target objectives, including improved DOTS implementation. Process improvements had become a routine part of their practice and were often diffused to other districts. Several teams said they now took more initiative in identifying problems and devising solutions. Others said that increased teamwork was improving the commitment of the NTP staff. CONCLUSION: Management training, including applied projects with coaching, can improve managerial and program performance of NTPs.

'New bottle, but old wine': from family planning to HIV/AIDS in post-Doi Moi Vietnam.

This paper begins with an observation that during the past two decades HIV/AIDS has emerged as a new public health priority in Vietnam and has commanded increasing attention and resources from both the government and the donor community. By juxtaposing HIV/AIDS with family planning, another social and health priority that preceded, and overlapped with, HIV/AIDS for a large part of the 1990s, we show two major gaps that have undermined both programmes. One is the lack of a strong civil society, that could have served as advocates for change, especially outside the government and the donor community. The other is the desire for control of women's bodies and sexuality that has been driven by the ever shifting project of nation building. We argue that these two major gaps represent more continuity than discontinuity in the way sexual and reproductive health issues are approached in Vietnam despite the seeming shift in priority that the emergence of HIV/AIDS suggests.

Survival and relapse rate of tuberculosis patients who successfully completed treatment in Vietnam.

SETTING: Reported tuberculosis (TB) cure rates are high in Vietnam with the 8-month short-course chemotherapy regimen. However, long-term treatment outcomes are unknown. OBJECTIVE: To assess survival and relapse rates among patients successfully treated for new smear-positive pulmonary tuberculosis (PTB). METHODS: A cohort of patients treated in 32 randomly selected districts in northern Vietnam were followed up 12-24 months after reported cure or treatment success for survival and bacteriologically confirmed relapse. Measurements included sputum smear examination, culture and interview for recent treatment history. RESULTS: Of 304 patients included in the study, no information was available for 31 (10%) and 19 (6%) had died. Bacteriology results were available for 244 (80%). The median interval between treatment completion and follow-up was 19 months. Relapse was recorded in 21/244 (8.6%, 95%CI 5.4-13), including 9 (4%) with positive sputum smears, 3 (1%) with negative smears but positive culture and 9 (4%) who had started TB retreatment. Four of 12 culture-positive relapse cases (33%) had multidrug-resistant strains. If the definition of relapse was extended to include death, reportedly due to TB, the relapse proportion was 26/263 (9.9%, 95%CI 6.6-14). CONCLUSION: A substantial proportion of patients (15%) had died or relapsed after being successfully treated for TB in northern Vietnam.

HLA-DRB1*04 and DRB1*10 are associated with resistance and susceptibility, respectively, in Brazilian and Vietnamese leprosy patients.

The host genetic background has been considered one of the factors that influence leprosy outcome, a chronic infectious disease caused by Mycobacterium leprae. Genome scans demonstrated that the 6p21 region is associated with leprosy and a substantial number of population-based studies analyzing human leukocyte antigen (HLA) class II loci suggested association of HLA-DR with leprosy. However, some studies lacked robustness as they had limited power. Indeed, experimental designs require increased sample size to achieve adequate power, as well as replication studies with independent samples for confirmation of previous findings. In this work, we analyzed the influence of the HLA-DRB1 locus on leprosy susceptibility per se and disease type using a case-control design carried out in Brazilians (578 cases and 691 controls) and a replication study based on a family design in a Vietnamese population (n=194 families). The results showed that HLA-DRB1*10 is associated with susceptibility to leprosy and HLA-DRB1*04 is associated with resistance, both in the Brazilian and Vietnamese populations suggesting that these alleles play an important role in the activation of cellular immune responses against M. leprae.