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Objectives: Previous studies indicate a high burden of diarrhoeal disease in Vietnamese children, however longitudinal community-based data on burden and aetiology are limited. The findings from a large, prospective cohort study of diarrhoeal disease in infants in southern Vietnam are presented herein. Methods: Infants were enrolled at birth in urban Ho Chi Minh City and a semi-rural district in southern Vietnam, and followed for 12 months (n = 6706). Diarrhoeal illness episodes were identified through clinic-based passive surveillance, hospital admissions, and self-reports. Results: The minimum incidence of diarrhoeal illness in the first year of life was 271/1000 infant-years of observation for the whole cohort. Rotavirus was the most commonly detected pathogen (50% of positive samples), followed by norovirus (24%), Campylobacter (20%), Salmonella (18%), and Shigella (16%). Repeat infections were identified in 9% of infants infected with rotavirus, norovirus, Shigella, or Campylobacter, and 13% of those with Salmonella infections. Conclusions: The minimum incidence of diarrhoeal disease in infants in both urban and semi-rural settings in southern Vietnam was quantified prospectively. A large proportion of laboratory-diagnosed disease was caused by rotavirus and norovirus. These data highlight the unmet need for a rotavirus vaccine in Vietnam and provide evidence of the previously unrecognized burden of norovirus in infants.

The SPOT-MAS assay "Screening for the Presence Of Tumor by Methylation And Size" detects the five most common cancers in Vietnam by evaluating circulating tumor DNA in the blood. Here, we validated its performance in a prospective multi-center clinical trial, K-DETEK. Our analysis of 2795 participants from 14 sites across Vietnam demonstrates its ability to detect cancers in asymptomatic individuals with a positive predictive value of 60%, with 83.3% accuracy in detecting tumor location. We present a case report to support further using SPOT-MAS as a complementary method to achieve early cancer detection and provide the opportunity for early treatment. [ABSTRACT FROM AUTHOR]

Aim: This study exploited hepatocellular carcinoma (HCC)-specific circulating DNA methylation profiles to improve the accuracy of a current screening assay for HCC patients in high-risk populations. Methods: Differentially methylated regions in cell-free DNA between 58 nonmetastatic HCC and 121 high-risk patients with liver cirrhosis or chronic hepatitis were identified and used to train machine learning classifiers. Results: The model could distinguish HCC from high-risk non-HCC patients in a validation cohort, with an area under the curve of 0.84. Combining these markers with the three serum biomarkers (AFP, lectin-reactive AFP, des-γ-carboxy prothrombin) in a commercial test, μTASWako®, achieved an area under the curve of 0.87 and sensitivity of 68.8% at 95.8% specificity. Conclusion: HCC-specific circulating DNA methylation markers may be added to the available assay to improve the early detection of HCC. The early detection of liver cancer in high-risk populations can help people with the disease have a higher chance of survival and better quality of life. However, this is still a healthcare challenge. Current commercial blood tests measuring protein signatures in the blood have low accuracy due to increased levels of these proteins being detected in both liver cancer patients and patients with chronic liver diseases. In this study, we identified a set of signatures in DNA released by cancer cells into the bloodstream and used them as biomarkers to distinguish liver cancer patients from high-risk patients. We also demonstrated that adding those signatures to a commercial blood test currently used in clinics could improve the accuracy in detecting liver cancer patients. Cancer-specific methylation markers combined with the three serum biomarkers (AFP, AFP-L3 and DCP) in a commercial diagnostic test, μTASWako, improve accuracy of liver cancer screening in high-risk populations. [ABSTRACT FROM AUTHOR]

Aims: Early detection of colorectal cancer (CRC) provides substantially better survival rates. This study aimed to develop a blood-based screening assay named SPOT-MAS ('screen for the presence of tumor by DNA methylation and size') for early CRC detection with high accuracy. Methods: Plasma cell-free DNA samples from 159 patients with nonmetastatic CRC and 158 healthy controls were simultaneously analyzed for fragment length and methylation profiles. We then employed a deep neural network with fragment length and methylation signatures to build a classification model. Results: The model achieved an area under the curve of 0.989 and a sensitivity of 96.8% at 97% specificity in detecting CRC. External validation of our model showed comparable performance, with an area under the curve of 0.96. Conclusion: SPOT-MAS based on integration of cancer-specific methylation and fragmentomic signatures could provide high accuracy for early-stage CRC detection. A novel blood test for early detection of colorectal cancer. Colorectal cancer is a cancer of the colon or rectum, located at the lower end of the digestive tract. The early detection of colorectal cancer can help people with the disease have a higher chance of survival and a better quality of life. Current screening methods can be invasive, cause discomfort or have low accuracy; therefore newer screening methods are needed. In this study we developed a new screening method, called SPOT-MAS, which works by measuring the signals of cancer DNA in the blood. By combining different characteristics of cancer DNA, SPOT-MAS could distinguish blood samples of people with colorectal cancer from those of healthy individuals with high accuracy. SPOT-MAS technology combines methylation and fragmentomic signatures of blood-based circulating tumor DNA in a multimodal deep-learning analysis to enable early detection of colorectal cancer with high accuracy. [ABSTRACT FROM AUTHOR]

Identification of tumor-derived mutation (TDM) in liquid biopsies (LB), especially in early-stage patients, faces several challenges, including low variant-allele frequencies, interference by white blood cell (WBC)-derived mutations (WDM), benign somatic mutations and tumor heterogeneity. Here, we addressed the above-mentioned challenges in a cohort of 50 nonmetastatic colorectal cancer patients, via a workflow involving parallel sequencing of paired WBC- and tumor-gDNA. After excluding potential false positive mutations, we detected at least one TDM in LB of 56% (28/50) of patients, with the majority showing low-patient coverage, except for one TDM mapped to KMT2D that recurred in 30% (15/30) of patients. [ABSTRACT FROM AUTHOR]

In this research, the kinetics of COD biodegradation and biogas production in a moving bed biofilm reactor (MBBR) at pilot scale (10 m3) for piggery wastewater treatment were investigated. Polyethylene (PE) was used as a carrying material, with organic loading rates (OLRs) of 10, 15, and 18 kgCOD/m3 day in accordance to hydraulic retention times (HRTs) of 0.56, 0.37, and 0.3 day. The results showed that a high COD removal efficiency was obtained in the range of 68–78% with the influent COD of 5.2–5.8 g/L at all 3 HRTs. About COD degradation kinetics, in comparison to the first- and second-order kinetics and the Monod model, Stover–Kincannon model showed the best fit with R2 0.98 and a saturation value constant (KB) and a maximum utilization rate (Umax) of 52.40 g/L day and 82.65 g/L day, respectively. The first- and second-order kinetics with all 3 HRTs and Monod model with the HRT of 0.56 day also obtained high R2 values. Therefore, these kinetics and models can be further considered to be used for predicting the kinetic characteristics of the MBBR system in piggery wastewater treatment process. The result of a 6-month operation of the MBBR was that biogas production was mostly in the operating period of days 17 to 80, around 0.2 to 0.3 and 0.15–0.20 L/gCODconverted, respectively, and then reduction at an OLR of 18 kgCOD/m3. After the start-up stage, day 35 biogas cumulative volume fluctuated from 20 to 30 m3/day and reached approximately 3500 m3 for 178 days during the whole digestive process. Methane is accounted for about 65–70% of biogas with concentration around 400 mg/L. [ABSTRACT FROM AUTHOR]

In this paper, we investigate effects of spatial heterogeneous environment and fast migration of individuals on the coexistence of the intraguild predation (IGP) dynamics. We present a two-patch model. We assume that on one patch two species compete for a common resource, and on the other patch one species can capture the other one for the maintenance. We also assume IGP individuals are able to migrate between the two patches and the migration process acts on a fast time scale in comparison with demography, predation and competition processes. We show that under certain conditions the heterogeneous environment and fast migration can lead to coexistence of the two species. [ABSTRACT FROM AUTHOR]

Background Shigella spp. are one of the most common causes of paediatric dysentery globally, responsible for a substantial proportion of diarrhoeal disease morbidity and mortality, particularly in industrialising regions. Alarming levels of antimicrobial resistance are now reported in S. flexneri and S. sonnei, hampering treatment options. Little is known, however, about the burden of infection and disease due to Shigella spp. in the community. Methods/Design In order to estimate the incidence of this bacterial infection in the community in Ho Chi Minh City, Vietnam we have designed a longitudinal cohort to follow up approximately 700 children aged 12-60 months for two years with active and passive surveillance for diarrhoeal disease. Children will be seen at 6 month intervals for health checks where blood and stool samples will be collected. Families will also be contacted every two weeks for information on presence of diarrhoea in the child. Upon report of a diarrhoeal disease episode, study nurses will either travel to the family home to perform an evaluation or the family will attend a study hospital at a reduced cost, where a stool sample will also be collected. Case report forms collected at this time will detail information regarding disease history, risk factors and presence of disease in the household. Outcomes will include (i) age-specific incidence of Shigella spp. and other agents of diarrhoeal disease in the community, (ii) risk factors for identified aetiologies, (iii) rates of seroconversion to a host of gastrointestinal pathogens in the first few years of life. Further work regarding the longitudinal immune response to a variety of Shigella antigens, host genetics and candidate vaccine/diagnostic proteins will also be conducted. Discussion This is the largest longitudinal cohort with active surveillance designed specifically to investigate Shigella infection and disease. The study is strengthened by the active surveillance component, which will likely capture a substantial proportion of episodes not normally identified through passive or hospital-based surveillance. It is hoped that information from this study will aid in the design and implementation of Shigella vaccine trials in the future. [ABSTRACT FROM AUTHOR]

Background: In Ho Chi Minh City, Vietnam, more than one-third of admissions to the two paediatric hospitals are attributable to four infectious syndromes: dengue, diarrhoeal disease, acute respiratory infection, and hand, foot and mouth disease. We have established a large prospective birth cohort study to investigate individual, environmental, virological, and immunological determinants of infection and disease in infants. Specific research questions are focused on the role of maternal antibody in protection against infection in infancy, and the adaptive immune response to vaccination and natural infection. This paper presents the cohort design, methods, and baseline characteristics of the participants enrolled in the first two years. Methods/design: Women are enrolled prior to delivery at one hospital in each of two catchment areas: an urban district in central HCMC, and a mixed urban/rural district in the Mekong Delta 150 km southwest of HCMC. Infants are enrolled within 3 days of birth, and maternal and cord blood samples are collected. Routine blood samples and data on growth, health status and vaccinations are collected from infants at scheduled visits at 4, 9 and 12 months. Clinical data and specimens are collected from infants presenting at a study clinic, or admitted to hospital, with any of the the four infectious syndromes of interest. Discussion: In four years since since the study began in July 2009, >6400 infants have been enrolled, and enrolment is ongoing. Attrition is low: 84% of participants have completed the full 12-month follow-up period. Baseline characteristics of the first 4300 enrollees are presented here. We have demonstrated the feasibility of establishing a large prospective study of infectious diseases in infancy in a resource-limited setting, with minimal loss to follow-up. Our linked socio-demographic, clinical and laboratory data will help elucidate the viral aetiology and epidemiology of common infectious diseases of infancy, and can inform the implementation of existing and future vaccines. This study furthermore provides a platform to which additional endpoints could be added in the future. [ABSTRACT FROM AUTHOR]

The article explores the seroprevalence of antibodies against human papillomavirus (HPV) types 16 (HPV16) and 18 (HPV18) in 7,074 women in five-year age groups from 15-19 to 65 and older in eight countries. The seropositivity for women who are HPV16 deoxyribonucleic acid (DNA)-positive was 39.8% and 23.2% for HPV18 DNA-positive. HPV DNA positive status increases the risk of cytologic abnormalities among HPV16 and/or HPV18 (HPV16/18) -seropositive women. There was an association observed between HPV16/18 and HPV DNA prevalence.

Dengue hemorrhagic fever can occur in primary dengue virus (DENV) infection of infants. The decay of maternally derived DENV immunoglobulin (Ig) G and the incidence of DENV infection were determined in a prospectively studied cohort of 1244 Vietnamese infants. Higher concentrations of total IgG and DENV-reactive IgG were found in cord plasma relative to maternal plasma. Maternally derived DENV-neutralizing and E protein-reactive IgG titers declined to below measurable levels in 190% of infants by 6 months of age. In contrast, IgG reactive with whole DENV virions persisted until 12 months of age in 20% of infants. Serological surveillance identified 10 infants with asymptomatic DENV infection for an incidence of 1.7 cases per 100 person-years. DENV-neutralizing antibodies remained measurable for ⩾1 year after infection. These results suggest that whereas DENV infection in infants is frequently subclinical, there is a window between 4 and 12 months of age where virion-binding but nonneutralizing IgG could facilitate antibody-dependent enhancement. [ABSTRACT FROM AUTHOR]

The pathogenesis of severe dengue is not well understood. Maternally derived subneutralizing levels of dengue virus-reactive IgG are postulated to be a critical risk factor for severe dengue during infancy. In this study, we found that, in healthy Vietnamese infants, there was a strong temporal association between the Fc-dependent, dengue virus infection-enhancing activity of neat plasma and the age-related epidemiology of severe dengue. We then postulated that disease severity in infants with primary infections would be associated with a robust immune response, possibly as a consequence of higher viral burdens in vivo. Accordingly, in infants hospitalized with acute dengue, the activation phenotype of peripheral-blood NK cells and CD8+ andCD4+ T cells correlated with overall disease severity, but HLA-A*1101-restricted NS3133-142-specific CD8+ T cells were not measurable until early convalescence. Plasma levels of cytokines/chemokines were generally higher in infants with dengue shock syndrome. Collectively, these data support a model of dengue pathogenesis in infants whereby antibody-dependent enhancement of infection explains the age-related case epidemiology and could account for antigen-driven immune activation and its association with disease severity. These results also highlight potential risks in the use of live attenuated dengue vaccines in infants in countries where dengue is endemic. [ABSTRACT FROM AUTHOR]

The pathogenesis of dengue in infants is poorly understood. We postulated that dengue severity in infants would be positively associated with markers of viral burden and that maternally derived, neutralizing antidengue antibody would have decayed before the age at which infants with dengue presented to the hospital. In 75 Vietnamese infants with primary dengue, we found significant heterogeneity in viremia and NS1 antigenemia at hospital presentation, and these factors were independent of disease grade or continuous measures of disease severity. Neutralizing antibody titers, predicted in each infant at the time of their illness, suggested that the majority of infants (65%) experienced dengue hemorrhagic fever when the maternally derived neutralizing antibody titer had declined to <1:20. Collectively, these data have important implications for dengue vaccine research because they suggest that viral burden may not solely explain severe dengue in infants and that neutralizing antibody is a reasonable but not absolute marker of protective immunity in infants. [ABSTRACT FROM AUTHOR]

Background Smoking increases the risk of squamous-cell carcinoma of the cervix, but it is not clear whether smoking increases the risk of acquisition or persistence of human papillomavirus (HPV) infection. Methods Information on smoking was collected from 10 areas in four continents among population-based, age-stratified random samples of women aged 15 years or older. HPV testing was performed using PCR-based enzyme immunoassay. Unconditional logistic regression was used to estimate odds ratios (OR) and corresponding 95% confidence intervals (CI) of being HPV-positive by smoking habits, adjusted for age and lifetime number of sexual partners. Results Ten thousand five hundred and seventy-seven women (mean age 41.4 years) were included. Among current smokers, the risk of being HPV-positive increased with smoking intensity, after allowing for lifetime number of sexual partners: ORs for Conclusions Our study suggests that current, though not former, smoking is associated with an increased prevalence of HPV, after allowance for sexual covariates. Among current smokers, HPV prevalence increased with smoking intensity, but a clear dose–response relationship was exclusively seen among women who declared one lifetime sexual partner. [ABSTRACT FROM AUTHOR]

Background: Multi-cancer early detection (MCED) through a single blood test significantly advances cancer diagnosis. However, most MCED tests rely on a single type of biomarkers, leading to limited sensitivity, particularly for early-stage cancers. We previously developed SPOT-MAS, a multimodal ctDNA-based assay analyzing methylation and fragmentomic profiles to detect five common cancers. Despite its potential, SPOT-MAS exhibited moderate sensitivities for early-stage cancers. This study investigated whether integrating hotspot mutations into SPOT-MAS could enhance its detection rates., Method: A targeted amplicon sequencing approach was developed to profile 700 hotspot mutations in cell-free DNA and integrated into the SPOT-MAS assay, creating a single-blood draw workflow. This workflow, namely SPOT-MAS Plus was retrospectively validated in a cohort of 255 non-metastatic cancer patients (breast, colorectal, gastric, liver, and lung) and 304 healthy individuals., Results: Hotspot mutations were detected in 131 of 255 (51.4%) cancer patients, with the highest rates in liver cancer (96.5%), followed by colorectal (59.3%) and lung cancer (53.7%). Lower detection rates were found for cancers with low tumor mutational burden, such as breast (31.3%) and gastric (41.9%) cancers. In contrast, SPOT-MAS demonstrated higher sensitivities for these cancers (51.6% for breast and 62.9% for gastric). The combination of hotspot mutations with SPOT-MAS predictions improved early-stage cancer detection, achieving an overall sensitivity of 78.5% at a specificity of 97.7%. Enhanced sensitivities were observed for colorectal (81.36%) and lung cancer (82.9%)., Conclusion: The integration of genetic and epigenetic alterations into a multimodal assay significantly enhances the early detection of various cancers. Further validation in larger cohorts is necessary to support broader clinical applications., (© 2025 The Author(s). Cancer Medicine published by John Wiley & Sons Ltd.)

Aim: Cancers lacking standard screening (LSS) options account for approximately 70% of cancer-related deaths due to late-stage diagnosis. Circulating tumor DNA (ctDNA) is a promising biomarker for multi-cancer early detection. We previously developed SPOT-MAS, a multimodal ctDNA-based assay analyzing methylation and fragmentomic profiles, effective in detecting common cancers (breast, colorectal, liver, lung and gastric). This study extends the analysis to five LSS cancers: endometrial, esophageal, head and neck, ovarian and pancreatic. Methods: SPOT-MAS was applied to profile cfDNA methylation and fragmentomic patterns in 739 healthy individuals and 135 LSS cancer patients. Results: We identified 347 differentially methylated regions and observed genome-wide hypomethylation across all five LSS cancers. Esophageal and head and neck cancers showed an enrichment of short cfDNA fragments (<150 bp). Eleven 4-mer end motifs were consistently altered in cfDNA fragments across all LSS cancers. Many significant signatures were consistent with previous observations in common cancers. Notably, SPOT-MAS achieved 96.2% specificity and 74.8% overall sensitivity, with a lower sensitivity of 60.7% in early-stage cancers. Conclusion: This proof-of-concept study demonstrates that SPOT-MAS a non-invasive test trained on five common cancer types, could detect a number of LSS cancer cases, potentially complementing existing screening programs.

Despite their promise, circulating tumor DNA (ctDNA)-based assays for multi-cancer early detection face challenges in test performance, due mostly to the limited abundance of ctDNA and its inherent variability. To address these challenges, published assays to date demanded a very high-depth sequencing, resulting in an elevated price of test. Herein, we developed a multimodal assay called SPOT-MAS (screening for the presence of tumor by methylation and size) to simultaneously profile methylomics, fragmentomics, copy number, and end motifs in a single workflow using targeted and shallow genome-wide sequencing (~0.55×) of cell-free DNA. We applied SPOT-MAS to 738 non-metastatic patients with breast, colorectal, gastric, lung, and liver cancer, and 1550 healthy controls. We then employed machine learning to extract multiple cancer and tissue-specific signatures for detecting and locating cancer. SPOT-MAS successfully detected the five cancer types with a sensitivity of 72.4% at 97.0% specificity. The sensitivities for detecting early-stage cancers were 73.9% and 62.3% for stages I and II, respectively, increasing to 88.3% for non-metastatic stage IIIA. For tumor-of-origin, our assay achieved an accuracy of 0.7. Our study demonstrates comparable performance to other ctDNA-based assays while requiring significantly lower sequencing depth, making it economically feasible for population-wide screening., Competing Interests: VN VTCN is affiliated with Gene Solutions. The author has no other competing interests to declare, TN HTN is affiliated with Gene Solutions. The author has no other competing interests to declare, ND NNTD is affiliated with Gene Solutions. The author has no other competing interests to declare, TP TMQP is affiliated with Gene Solutions. The author has no other competing interests to declare, GN GTHN is affiliated with Gene Solutions. The author has no other competing interests to declare, TN TDN is affiliated with Gene Solutions. The author has no other competing interests to declare, TT TTTT is affiliated with Gene Solutions. The author has no other competing interests to declare, DV, TP, TJ, VN, HN, TN, QD, TD, AT, VN, VN, LH, QT, TP, TH, BN, TN, TN, DP, BP, TV, TN, TT, MT, NT, TL, TT, MD, HB, VK, TP, DT, TL, TP, ML, VC, TD No competing interests declared, TN THHN is affiliated with Gene Solutions. The author has no other competing interests to declare, LH LAKH is affiliated with Gene Solutions. The author has no other competing interests to declare, TT THT is affiliated with Gene Solutions. The author has no other competing interests to declare, DV DHV is affiliated with Gene Solutions. The author has no other competing interests to declare, TT TMTT is affiliated with Gene Solutions. The author has no other competing interests to declare, MN MNN is affiliated with Gene Solutions. The author has no other competing interests to declare, TV TTVV is affiliated with Gene Solutions. The author has no other competing interests to declare, AN ANN is affiliated with Gene Solutions. The author has no other competing interests to declare, TT TTT is affiliated with Gene Solutions. The author has no other competing interests to declare, VT VUT is affiliated with Gene Solutions. The author has no other competing interests to declare, ML MPL is affiliated with Gene Solutions. The author has no other competing interests to declare, TD TTD is affiliated with Gene Solutions. The author has no other competing interests to declare, TP TVP is affiliated with Gene Solutions. The author has no other competing interests to declare, HN HDN is affiliated with Gene Solutions. The author has no other competing interests to declare, DN DSN holds equity in Gene Solutions.DSN is affiliated with Gene Solutions. The author has no other competing interests to declare, DT DKT is affiliated with Gene Solutions. The author has no other competing interests to declare, HT HST is affiliated with Gene Solutions. The author has no other competing interests to declare, HG HG holds equity in Gene Solutions. The funder Gene Solutions provided support in the form of salaries for HG who is inventor on the patent application (USPTO 17930705).HG is affiliated with Gene Solutions. The author has no other competing interests to declare, HN HNN holds equity in Gene Solutions. The funder Gene Solutions provided support in the form of salaries for HNN who is inventor on the patent application (USPTO 17930705).HNN is affiliated with Gene Solutions. The author has no other competing interests to declare, MP MDP holds equity in Gene Solutions. The funder Gene Solutions provided support in the form of salaries for MDP who is inventor on the patent application (USPTO 17930705).MDP is affiliated with Gene Solutions. The author has no other competing interests to declare, LT LST holds equity in Gene Solutions. The funder Gene Solutions provided support in the form of salaries for LST who is inventor on the patent application (USPTO 17930705).LST is affiliated with Gene Solutions. The author has no other competing interests to declare, (© 2023, Nguyen, Nguyen et al.)

Introduction: Breast cancer causes the most cancer-related death in women and is the costliest cancer in the US regarding medical service and prescription drug expenses. Breast cancer screening is recommended by health authorities in the US, but current screening efforts are often compromised by high false positive rates. Liquid biopsy based on circulating tumor DNA (ctDNA) has emerged as a potential approach to screen for cancer. However, the detection of breast cancer, particularly in early stages, is challenging due to the low amount of ctDNA and heterogeneity of molecular subtypes., Methods: Here, we employed a multimodal approach, namely Screen for the Presence of Tumor by DNA Methylation and Size (SPOT-MAS), to simultaneously analyze multiple signatures of cell free DNA (cfDNA) in plasma samples of 239 nonmetastatic breast cancer patients and 278 healthy subjects., Results: We identified distinct profiles of genome-wide methylation changes (GWM), copy number alterations (CNA), and 4-nucleotide oligomer (4-mer) end motifs (EM) in cfDNA of breast cancer patients. We further used all three signatures to construct a multi-featured machine learning model and showed that the combination model outperformed base models built from individual features, achieving an AUC of 0.91 (95% CI: 0.87-0.95), a sensitivity of 65% at 96% specificity., Discussion: Our findings showed that a multimodal liquid biopsy assay based on analysis of cfDNA methylation, CNA and EM could enhance the accuracy for the detection of early- stage breast cancer., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Pham, Phan, Jasmine, Tran, Huynh, Vo, Nai, Tran, Truong, Tran, Nguyen, Nguyen, Nguyen, Le, Nguyen, Nguyen, Truong, Do, Phan, Giang, Nguyen and Tran.)

Background: Shigella sonnei is an emergent and major diarrheal pathogen for which there is currently no vaccine. We aimed to quantify duration of maternal antibody against S. sonnei and investigate transplacental IgG transfer in a birth cohort in southern Vietnam., Methods and Results: Over 500-paired maternal/infant plasma samples were evaluated for presence of anti-S. sonnei-O IgG and IgM. Longitudinal plasma samples allowed for the estimation of the median half-life of maternal anti-S. sonnei-O IgG, which was 43 days (95% confidence interval: 41-45 days). Additionally, half of infants lacked a detectable titer by 19 weeks of age. Lower cord titers were associated with greater increases in S. sonnei IgG over the first year of life, and the incidence of S. sonnei seroconversion was estimated to be 4/100 infant years. Maternal IgG titer, the ratio of antibody transfer, the season of birth and gestational age were significantly associated with cord titer., Conclusions: Maternal anti-S. sonnei-O IgG is efficiently transferred across the placenta and anti-S. sonnei-O maternal IgG declines rapidly after birth and is undetectable after 5 months in the majority of children. Preterm neonates and children born to mothers with low IgG titers have lower cord titers and therefore may be at greater risk of seroconversion in infancy., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The incidence rate of invasive cervical carcinoma (ICC) is 4-fold higher in Ho Chi Minh City, in the South of Vietnam, than in Hanoi, in the North. Thus, we explored the prevalence of and the risk factors for human papillomavirus (HPV) infection in these 2 areas. A population-based random sample of married women aged 15-69 years were interviewed and had a gynaecological examination in the urban district of Ho Chi Minh City and in a peri-urban district in Hanoi. HPV DNA detection was performed using a GP5+/6+ primer-mediated PCR enzyme immunoassay. A total of 922 women from Ho Chi Minh and 994 from Hanoi, for whom a Pap smear and HPV-status were available, were evaluated. HPV DNA was detected among 10.9% of women in Ho Chi Minh City and 2.0% in Hanoi (age standardized prevalence, world standard population: 10.6% and 2.3%, respectively). In the 2 areas combined, 30 different HPV types were found, the most common being HPV 16 (in 14 single and 18 multiple infections), followed by HPV 58, 18 and 56. A peak of HPV DNA detection in women younger than age 25 was found in Ho Chi Minh City (22.3%) but not in Hanoi. Major risk factors for HPV DNA detection were indicators of sexual habits, most notably the presence of HSV-2 antibodies, nulliparity and the current use of oral contraceptives. Women in Hanoi showed the lowest HPV prevalence ever reported so far, suggesting that HPV has not spread widely in this population. As expected, HPV prevalence in a population seemed to be closely correlated with ICC incidence rates., (Copyright 2003 Wiley-Liss, Inc.)