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Shrimp farming and exporting is the main income source for the southern coastal districts of the Mekong Delta. Monitoring these shrimp ponds is helpful in identifying losses incurred due to natural calamities like floods, sources of water pollution by chemicals used in shrimp farming, and changes in the area of cultivation with an increase in demand for shrimp production. Satellite imagery, which is consistent with good spatial resolution and helpful in providing frequent information with temporal imagery, is a better solution for monitoring these shrimp ponds remotely for a larger spatial extent. The shrimp ponds of Cai Doi Vam township, Ca Mau Province, Viet Nam, were mapped using DMC-3 (TripleSat) and Jilin-1 high-resolution satellite imagery for the years 2019 and 2022. The 3 m spatial resolution shrimp pond extent product showed an overall accuracy of 87.5%, with a producer's accuracy of 90.91% (errors of omission = 11.09%) and a user's accuracy of 90.91% (errors of commission = 11.09%) for the shrimp pond class. It was noted that 66 ha of shrimp ponds in 2019 were observed to be dry in 2022, and 39 ha of other ponds had been converted into shrimp ponds in 2022. The continuous monitoring of shrimp ponds helps achieve sustainable aquaculture and acts as crucial input for the decision makers for any interventions. [ABSTRACT FROM AUTHOR]

Electrical and electronic waste (e-waste) has become a global concern, especially in developing countries. In this review, we conducted a literature survey of e-waste management practices, processing activities, and adverse effects in Vietnam, an emerging country in Southeast Asia, by gathering data from peer-reviewed articles published between 2009 and 2021. This is the first review paper to comprehensively discuss management and research aspects regarding e-waste in an Asian developing country. Due to the lack of an effective management and recycling system, a certain portion of Vietnamese e-waste has been processed by informal sectors without appropriate recycling and pollution control technology, resulting in localized contamination and human exposure to toxic chemicals. Primitive processing activities, such as manual dismantling, open burning, and plastic recycling, have been identified as important contributors to the environmental emission and human exposure to toxic elements (notably As, Mn, Ni, Pb, Zn) and organic pollutants like flame retardants, PAHs, PCBs, and dioxin-related compounds. Informal e-waste processing from these small-scale workshops can release pollutants at similar levels compared to large-scale facilities in developed countries. This fact suggests an urgent need to develop management best practices for e-waste in Vietnam as well as other emerging and developing countries, in order to increase recycling efficiency and minimize their adverse impacts on environmental and human health. [ABSTRACT FROM AUTHOR]

Antenatal maternal mental health status not only predicts postpartum mental status, but also influences family health. In Asia, however, little scientific research has been conducted on antenatal parenting intervention to date, nor has there been much emphasis on fathers in considerations of parenting support. Building upon our past research achievements that showed a strong need for parenting support focusing on the mental health aspect in Japan and Vietnam, we report on the process of adapting an Australian antenatal group-based psychosocial intervention involving fathers into Japanese and Vietnamese public service settings. The intervention was feasible at given sites and well accepted among volunteer couples. The presented processes to ease adaptation may be useful to other health professionals in Asian regions undertaking similar initiatives. (Contains 3 tables.)

Livestock manure and its management are significant sources of greenhouse gas (GHG). In most Southeast Asian countries, the current GHG emissions are estimated by the Intergovernmental Panel on Climate Change (IPCC) Tier 1 approach using default emission factors. Sun-drying is the dominant manure treatment in Vietnam, and in this study, we measured GHG emissions during manure drying using a chamber-based approach. Results show the emission factors for CH4 and N2O were 0.295 ± 0.078 g kg−1 volatile solids (VS) and 0.132 ± 0.136 g N2O-N kg−1 Ninitial, respectively. We monitored the total bacterial/archaeal community using 16S rRNA gene amplicon sequencing and measured the abundance of functional genes required for methanogenesis (mcrA), nitrification (amoA) and denitrification (nirK, nirS and nosZ) processes. Methane emission occurred only at the beginning of the drying process (days 1 to 3). The results of amplicon sequencing indicated that the relative abundance of methanogens also decreased during this period. Although some nitrification activity was detected, there was no significant N2O emission. These findings well describe the manure management system in south Vietnam and the GHG emission from this manure category, paving the way for higher Tier estimations using country-specific values. [ABSTRACT FROM AUTHOR]

Carbapenem-resistant Enterobacterales (CRE) represent a serious threat to public health due to the lack of treatment and high mortality. The rate of antimicrobial resistance of Enterobacterales isolates to major antimicrobials, including carbapenems, is much higher in Vietnam than in Western countries, but the reasons remain unknown due to the lack of genomic epidemiology research. A previous study suggested that carbapenem resistance genes, such as the carbapenemase gene blaNDM, spread via plasmids among Enterobacterales in Vietnam. In this study, we characterized blaNDM-carrying plasmids in Enterobacterales isolated in Vietnam, and identified several possible cases of horizontal transfer of plasmids both within and among species of bacteria. Twenty-five carbapenem-nonsusceptible isolates from a medical institution in Hanoi were sequenced on Illumina short-read sequencers, and 13 blaNDM-positive isolates, including isolates of Klebsiella pneumoniae, Escherichia coli, Citrobacter freundii, Morganella morganii, and Proteus mirabilis, were further sequenced on an Oxford Nanopore Technologies long-read sequencer to obtain complete plasmid sequences. Almost identical 73 kb IncFII(pSE11)::IncN hybrid plasmids carrying blaNDM-1 were found in a P. mirabilis isolate and an M. morganii isolate. A 112 kb IncFII(pRSB107)::IncN hybrid plasmid carrying blaNDM-1 in an E. coli isolate had partially identical sequences with a 39 kb IncR plasmid carrying blaNDM-1 and an 88 kb IncFII(pHN7A8)::IncN hybrid plasmid in a C. freundii isolate. 148–149 kb IncFIA(Hl1)::IncA/C2 plasmids and 75–76 kb IncFII(Yp) plasmids, both carrying blaNDM-1 were shared among three sequence type 11 (ST11) isolates and three ST395 isolates of K. pneumoniae, respectively. Most of the plasmids co-carried genes conferring resistance to clinically relevant antimicrobials, including third-generation cephalosporins, aminoglycosides, and fluoroquinolones, in addition to blaNDM-1. These results provide insight into the genetic basis of CRE in Vietnam, and could help control nosocomial infections. [ABSTRACT FROM AUTHOR]

SUMMARY Morphology and phylogeny of small armored dinoflagellate Azadinium species isolated from Japanese and Vietnamese coasts were examined by light microscopy, scanning electron microscopy and molecular phylogeny inferred from ITS and LSU rDNA (D1–D3) sequences. Dominant azaspiracids (AZAs) were analyzed by using liquid chromatography/triple quadrupole mass spectrometer (LC/MS/MS). Sixteen and four culture strains were established from Japan and Vietnam, respectively. A phylogenetic tree confirmed our species identifications of Japanese cultures as Azadinium poporum (ribotypes A, B and C), A. trinitatum and A. zhuanum, and Vietnamese cultures as A. poporum (ribotype B). Typical cells of A. poporum had the thecal tabulation of Po, cp, X, 4′, 3a, 6″, 6C, 5S, 6″′, 2″″, A. trinitatum had Po, cp, X, 4–5′, 3a, 6–7″, 6C, 5S, 5–6″′, 2″″ and A. zhuanum had Po, cp, X, 3–4′, 2a, 6″, 6C, 5S, 6″′, 2″″. Cellular morphology of the three species were congruent with those in the original reports, in terms of the presence/absence of antapical spine and the position of the ventral pore, nucleus and pyrenoids, although small differences were also found in the nucleus position of A. trinitatum and A. zhuanum. AZA‐2 was the dominant component in Japanese A. poporum (ribotypes A, B and C), and AZA‐40 in Vietnamese A. poporum (ribotype B). AZA‐2 and AZA‐40 were not detected in Vietnamese and Japanese A. poporum, respectively. AZA analogs were not detected from A. trinitatum and A. zhuanum. This is the first report of the toxigenic A. poporum from Japan and Vietnam, with identifications of the major AZAs. The ribotype A of A. poporum and A. trinitatum were the first records in Asia. [ABSTRACT FROM AUTHOR]

Neurotoxic poisonings with fatal symptoms caused by consumption of Nassarius gastropods have been reported in Vietnam but the causative toxins have not been confirmed. In the present study, Nassarius conoidalis, N. glans and N. pullus, which are considered to be common causative species, were collected in Khanh Hoa province, Vietnam in May 2016 for toxin analysis using LC/MS/MS. The results confirmed that TTX is a dominant toxin in these gastropods. Among them, N. glans exhibited the highest toxicity (412.7 ± 107.3 MU/g), followed by N. conoidalis (144.8 ± 82.0 MU/g) and N. pullus (19.6 ± 9.8 MU/g). This is the first report confirming TTX in these species. All specimens in this study were hightly toxic, indicating that the frequency of toxic specimens of the three Nassarius species is extremely high. Further, their toxicities were all beyond the regulatory level of consumption (10 MU/g) for puffer(fish) as recommended in Japan. The present data indicates that N. conoidalis, N. glans and N. pullus are not suitable for food in Vietnam. [ABSTRACT FROM AUTHOR]

Background: Scrub typhus (ST) is a leading cause of non-malarial febrile illness in Southeast Asia, but evidence of its true disease burden is limited because of difficulties of making the clinical diagnosis and lack of adequate diagnostic tests. To describe the epidemiology and clinical characteristics of ST, we conducted an observational study using multiple diagnostic assays at a national tertiary hospital in Hanoi, Vietnam. Methodology/Principal findings: We enrolled 1,127 patients hospitalized with documented fever between June 2012 and May 2013. Overall, 33 (2.9%) patients were diagnosed with ST by PCR and/or screening of ELISA for immunoglobulin M (IgM) with confirmatory tests: 14 (42.4%) were confirmed by indirect immunoperoxidase assay (IIP), and 19 (57.6%) were by IIP and PCR. Living by farming, conjunctival injection, eschar, aspartate aminotransferase elevation, and alanine aminotransferase elevation were significantly associated with ST cases (adjusted odds ratios (aORs): 2.8, 3.07, 48.8, 3.51, and 4.13, respectively), and having a comorbidity and neutrophilia were significantly less common in ST cases (aORs: 0.29 and 0.27, respectively). The majority of the ST cases were not clinically diagnosed with rickettsiosis (72.7%). Dominant IIP reactions against a single antigen were identified in 15 ST cases, whereas indistinguishably high reactions against multiple antigens were seen in 11 ST cases. The most frequently observed dominant IIP reaction was against Karp antigen (eight cases) followed by Gilliam (four cases). The highest diagnostic accuracy of IgM ELISA in acute samples was 78%. In a phylogenetic analysis of the 56-kDa type-specific antigen gene, the majority (14 cases) were located in the Karp-related branch followed by the Gilliam-related (two cases), Kato-related (two cases), and TA763-related clades (one case). Conclusions/Significance: Both the clinical and laboratory diagnoses of ST remain challenging at a tertiary hospital. Implementation of both serological and nucleic acid amplification assays covering endemic O. tsutsugamushi strains is essential. Author summary: Acute fever without localized signs is a common presentation of communicable neglected tropical diseases (NTDs). Scrub typhus, a potentially severe chigger-borne intracellular bacterial infection, is also an important differential diagnosis of acute febrile NTDs, which is endemic particularly in Asia. In Vietnam, the proportion of scrub typhus cases among patients with acute fever is currently unknown even in a tertiary hospital, because both clinical and laboratory diagnoses of scrub typhus are challenging. In this study, we enrolled acute fever patients hospitalized in the department of infectious diseases at a national tertiary hospital in Hanoi through a year. Scrub typhus was diagnosed using serological and PCR assays in 2.9% of enrolled patients. We found that the characteristics of scrub typhus patients were generally non-specific and most cases were missed based on clinical diagnosis alone. We also found that currently available serological assays were sub-optimal in Vietnam by comparing multiple diagnostic assays. Since the diagnostic antigens were not originally from Vietnam, the serological findings may underrepresent the actual number of cases. The presented data underlines the importance of a preemptive treatment strategy for scrub typhus among acute fever patients and adaptation of diagnostic assays to cover endemic strains. [ABSTRACT FROM AUTHOR]

Coprinopsis neocinerea sp. nov. (Basidiomycota, Agaricales , Psathyrellaceae), is a new Coprinoid ammonia fungus from broadleaf mixed forest in Vietnam. In macro- and micromorphology, this species is similar to C. cinerea , but differs in having upheaved and humpbacked abaxial side shape of basidiospores. Phylogenetic analysis with nuclear ribosomal internal transcribed spacer (ITS) data also supports this new taxon. • One new ammonia fungus Coprinopsis neocinerea from Vietnam is described. • Phylogenetic analysis supported species in genus Coprinopsis subsection Lanatuli. • This new species is distinct by having an upheaved and humpacked basidiospores. [ABSTRACT FROM AUTHOR]

Liver cirrhosis (LC) is a disease characterized by pathological accumulation and alteration of extracellular matrix (ECM) proteins; the interaction between two such proteins, collagen and vitronectin (VN), is considered to be the key to controlling ECM remodeling in liver cirrhosis. If it is possible to control the modification of oligosaccharides on VN, it may be possible to retard progression of liver cirrhosis. In this study, we examined the relationship between changes in VN glycosylation and activity related to the remodeling of hepatic tissue in human LC and a rat model of LC generated using carbon tetrachloride (CCl4). Plasma concentrations of VN in human LC declined to approximately two‐thirds that in normal plasma, but the ratio of active VN, which has collagen‐binding activities, increased 2.8 times in LC plasma. In contrast, purified LC‐VN exhibited similar binding activities toward type I, IV, and V collagens to those of normal VN. Lectin reactivities and carbohydrate analyses of LC‐VN revealed that branching, fucosylation, and sialylation of N‐glycans were higher than those of normal VN. On the other hand, the plasma level of rat CCl4‐VN increased and the ratio of active molecules to collagen in plasma decreased. Increased fucosylation of LC‐VN was not detected in carbohydrates of CCl4‐VN. The changes in rat VN due to CCl4 treatment did not correspond to the changes in plasma levels of human VN caused by LC, the ratio of active molecules, or carbohydrate composition, thereby indicating that CCl4‐treated rats are not an appropriate model for studying VNs in human LC. Glycosidase treatment of VNs supported the hypothesis that the collagen‐binding activity of VN is modulated by alterations of glycosylation during LC, which may contribute to (a) the matrix incorporation of VN and (b) tissue fibrosis. Vitronectin (VN) is a glycoprotein synthesized mainly by the liver. This study showed that plasma VN level, active ratio, and its glycosylation are altered in human liver cirrhosis (LC), and that these changes differed from changes in CCl4‐treated rats. The results of glycosidase treatment supported the hypothesis that the collagen‐binding activity of VN is modulated by alterations of glycosylation in LC. [ABSTRACT FROM AUTHOR]

While export-oriented shrimp farming has become an important source of income for many small-scale farmers in developing countries, the rate at which products are rejected at the ports of developed countries has remained high mainly due to the overuse of antibiotics. To reveal what determines the overuse of antibiotics, we interviewed 201 shrimp farmers in Viet Nam in 2015 and collected shrimp samples from each household's pond for the screening of residual drugs. These tests revealed that residual drugs exceeding acceptable limits by Japanese standards were found in the samples of 40 farmers. We conducted cross-sectional Logit and Tobit regressions to examine whether results of the residue tests are significantly associated with farmers' characteristics and management practices. This study finds that: (1) receiving BMP training has a significant and positive effect on reducing residual drugs; (2) if farmers know multiple extension officers, these relationships have significant and positive effects on reducing residual drugs; and (3) farmers with experience of shrimp disease outbreaks reduce use of antibiotics. Overall, this study contributes to revealing the determinants of detecting veterinary drug residues in shrimp farming in multiple (social, economic and psychological) dimensions. [ABSTRACT FROM AUTHOR]

We examine effective measures to reduce the use of prohibited antibiotics among shrimp farmers in Southern Vietnam based on an econometrics approach. We implemented a randomized controlled trial with three interventions: a) providing a technical workshop, b) quantifying the unobserved residue level of antibiotics, and c) offering price premiums for higher quality shrimp, defined as the absence of major prohibited antibiotics in our study. Using three years of panel data, we estimate the intention-to-treat effects of each intervention and find that quantifying the residue level had strong positive effects in improving farmers' knowledge and practices and reducing the probability of detecting antibiotics ex post. This result is driven by those farmers who had positive detection ex ante. Our findings suggest that providing residue test results for farmers is an effective way to solve the antibiotic residue problems in aquacultural sector in developing countries. (145 words). • Quantifying residues of antibiotics improves farmers' knowledge and practices. • Quantifying residues also reduces the probability of antibiotics detection ex post. • Farmers who had positive detection ex ante changed farming practices ex post. [ABSTRACT FROM AUTHOR]

Background: The incidence of gastric cancer in the Northern city, Hanoi is higher than in the Southern city, Ho Chi Minh, Vietnam. We previously reported that Helicobacter pylori vacA m1 genotype might be responsible for the difference between the two cities, however, the study only included non-cancer patients. The aim of this study is to investigate the non-cardia gastric cancer characteristics and the role of H. pylori virulence on different non-cardia gastric cancer incidence between two cities in Vietnam. Methods and Results: We recruited 282 non-cardia gastric cancer patients that had undergone gastroscopy in two cities, Ho Chi Minh and Hanoi, Vietnam. Characteristics of non-cardia gastric cancer were late age of onset (mean age, 62.5 years), predominance in males (ratio of males/females; 3.9:1), diffuse type (55.3%), and high prevalence of H. pylori infection (79.4%). H. pylori infection and the vacA m1 genotype conferred an increased risk for GC (OR, 2.02; 95% CI 1.4-3.0; P = 0.0003 and OR, 2.7; 95% CI 1.5-4.7; P = 0.001, respectively). Interestingly, the presence of vacA m1 genotype in the gastric cancer group was significantly higher than that in the non-cancer group (68.8% vs 44.9%, P = 0.001) and the significant tendency still observed in Ho Chi Minh (67.6% vs 31.9%, P < 0.0001). Conclusion: We first describe the characteristics of non-cardia gastric cancer in Vietnam. Helicobacter pylori infection was associated with the development of non-cardia GC. vacA m1 genotype might contribute to incidence differences between the two cities. [ABSTRACT FROM AUTHOR]

During a 2014 measles outbreak in Vietnam, postmortem pathologic examination of hospitalized children who died showed that adenovirus type 7 pneumonia was a contributory cause of death in children with measles-associated immune suppression. Adenovirus type 7 pneumonia should be recognized as a major cause of secondary infection after measles. [ABSTRACT FROM AUTHOR]

Information about the co-occurrence of halogenated flame retardants (HFRs) and organophosphate esters (OPEs) in the environment of informal waste processing areas is still limited, especially in emerging and developing countries. In this study, OPEs and HFRs including polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), and chlorinated flame retardants (CFRs) were determined in settled dust from Vietnamese e-waste recycling (WR) and vehicle processing (VP) workshops. Pollutant concentrations decreased in the order: OPEs (median 1500; range 230–410,000 ng/g) ≈ PBDEs (1200; 58–250,000) > NBFRs (140; not detected – 250,000) > CFRs (13; 0.39–2200). HFR and OPE levels in the WR workshops for e-waste and obsolete plastic were significantly higher than in the VP workshops. Decabromodiphenyl ether and decabromodiphenyl ethane are major HFRs, accounting for 60 ± 26% and 25 ± 29% of total HFRs, respectively. Triphenyl phosphate, tris(2-chloroisopropyl) phosphate, and tris(1,3-dichloroisopropyl) phosphate dominated the OPE profiles, accounting for 30 ± 25%, 25 ± 16%, and 24 ± 18% of total OPEs, respectively. The OPE profiles differed between WR and VP dust samples, implying different usage patterns of these substances in polymer materials for electric/electronic appliance and automotive industries. Human health risk related to dust-bound HFRs and OPEs in the study areas was low. [Display omitted] • Pollutant levels in dust were in the order: PBDEs ≈ OPEs > NBFRs > CFRs. • Informal e-waste recycling activities were potential source of HFRs and OPEs. • BDE-209, DBDPE, and TPHP were major compounds in e-waste recycling sites. • Vehicle workshop dust had low HFR levels and specific OPE profiles. • OPE sources and emission from vehicle processing should be further investigated. [ABSTRACT FROM AUTHOR]

This study sought to monitor the presence of carbapenem-resistant Enterobacteriaceae (CRE) and the proportion New Delhi metallo-beta-lactamase 1 (NDM-1)-producing bacteria between August 2010 and December 2012 in a surgical hospital in Vietnam. We identified 47 CRE strains from a total of 4,096 Enterobacteriaceae isolates (1.1 %) that were NDM-1-positive from 45 patients admitted to 11 different departments, with the majority being from the urology department. The NDM-1 gene was found in seven different species. Genotyping revealed limited clonality of NDM-1-positive isolates. Most of the isolates carried the NDM-1 gene on a plasmid and 17.8 % (8/45) of those were readily transferable. We found five patients at admission and one patient at discharge with NDM-1-positive bacteria in their stool. From 200 screening environmental hospital samples, five were confirmed to be NDM-1-positive and included Acinetobacter species ( n = 3) and Enterobacter aerogenes ( n = 2). The results reveal that NDM-1-producing Enterobacteriaceae are commonly isolated in patients admitted to a Vietnamese surgical hospital and are also detected in the hospital environment. [ABSTRACT FROM AUTHOR]

Gastric cancer is a significant health problem in Asia. Although the prevalence of Helicobacter pylori infection is similar in Bhutan, Vietnam, and Myanmar, the incidence of gastric cancer is highest in Bhutan, followed by Vietnam and Myanmar. We hypothesized that H. pylori virulence factors contribute to the differences. The status of cagA, vacA, jhp0562, and β-(1,3)galT(jhp0563) was examined in 371 H. pylori-infected patients from Bhutan, Vietnam, and Myanmar. Each virulence factor could not explain the difference of the incidence of gastric cancer. However, the prevalence of quadruple-positive for cagA, vacA s1, vacA m1, and jhp0562-positive/β-(1,3)galT-negative was significantly higher in Bhutan than in Vietnam and Myanmar and correlated with gastric cancer incidence. Moreover, gastritis-staging scores measured by histology of gastric mucosa were significantly higher in quadruple-positive strains. We suggest that the cagA, vacA s1, vacA m1, and jhp0562-positive/β-(1,3)galT-negative genotype may play a role in the development of gastric cancer. [ABSTRACT FROM AUTHOR]

Two strains of Pseudo- nitzschia fukuyoi isolated from Vietnamese waters produce domoic acid, a toxin responsible for amnesic shellfish poisoning. Species identification was based on detailed morphological observation using a transmission electron microscope and also molecular data on large subunit (LSU) and the second internal transcribed spacer (ITS2) with NCBI nucleotide Blast (blastn). Toxin productivity of the two strains was confirmed and their range were 3.85-4.54 pg/cell by analyses using LC-MS/MS. This is the first report of occurrence of P. fukuyoi in Vietnamese waters, and the first confirmation of productivity of domoic acid of the species. [ABSTRACT FROM AUTHOR]

Hantaviruses are harbored by multiple small mammal species in Asia, Europe, Africa, and the Americas. To ascertain the geographic distribution and virus-host relationships of rodent-borne hantaviruses in Japan, Vietnam, Myanmar, and Madagascar, RNAlater™-preserved lung tissues of 981 rodents representing 40 species, collected in 2011–2017, were analyzed for hantavirus RNA by RT-PCR. Our data showed Hantaan orthohantavirus Da Bie Shan strain in the Chinese white-bellied rat (Niviventer confucianus) in Vietnam, Thailand; orthohantavirus Anjo strain in the black rat (Rattus rattus) in Madagascar; and Puumala orthohantavirus Hokkaido strain in the grey-sided vole (Myodes rufocanus) in Japan. The Hokkaido strain of Puumala virus was also detected in the large Japanese field mouse (Apodemus speciosus) and small Japanese field mouse (Apodemus argenteus), with evidence of host-switching as determined by co-phylogeny mapping. [ABSTRACT FROM AUTHOR]

Plastic pollution has become one of the most pressing environmental issues. Recycling is a potential means of reducing plastic pollution in the environment. However, plastic fragments are still likely released to the aquatic environment during mechanical recycling processes. Here, we examined the plastic inputs and effluent outputs of three mechanical recycling facilities in Vietnam dealing with electronic, bottle, and household plastic waste, and we found that large quantities of microplastics (plastics <5 mm in length) are generated and released to the aquatic environment during mechanical recycling without proper treatment. Comparisons with literature data for microplastics in wastewater treatment plant effluents and surface water indicated that mechanical recycling of plastic waste is likely a major point source of microplastics pollution. Although there is a mismatch between the size of the microplastics examined in the present study and the predicted no-effect concentration reported, it is still possible that microplastics generated at facilities pose risks to the aquatic environment because there might be many plastic particulates smaller than 315 μm, as suggested by our obtained size distributions. With mechanical recycling likely to increase as we move to a circular plastics economy, greater microplastics emissions can be expected. It is therefore an urgent need to fully understand not only the scale of microplastic generation and release from plastic mechanical recycling but also the environmental risk posed by microplastics in the aquatic environment. [Display omitted] • Mechanical recycling without wastewater treatment was at least a source of microplastic. • Effluent microplastic concentrations were from 1.1 × 105–2.0 × 108 MP particulates/m3. • Annual microplastic emissions from these facilities were from 0.014 to 5.8 t/year. [ABSTRACT FROM AUTHOR]

Although informal e-waste recycling sites (EWRSs) are hotspots of both polychlorinated and polybrominated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs and PBDD/Fs), human exposure to the latter has not been studied in details. This study investigated the accumulation levels and profiles of dioxin-related compounds (DRCs) in breast milk samples from women living in two Vietnamese EWRSs and estimated the intake contribution from e-waste-related exposure. Screening results using Dioxin-Responsive Chemically Activated LUciferase gene eXpression assay (DR-CALUX) showed higher dioxin-like (DL) activities in samples from the EWRS Bui Dau than in those from the EWRS Trang Minh and a reference site (2.3–10 vs 1.7–4.8 and 0.60–5.7pg CALUX-TEQ/g lipid, n=10, 6 and 9, respectively). Chemical analysis results of selected samples show that the WHO-TEQ levels of PCDD/Fs, DL-PCBs and PBDD/Fs in EWRS samples were not significantly higher than in those from the reference site (0.22–7.4 vs 1.1–3.0pg/g lipid) and within the Vietnamese background range, but women involved in recycling accumulated higher concentrations of PCDFs (13–15 vs 2.3–8.8pg/g lipid) and PBDFs (1.1–1.5 vs <1.1pg/g lipid). By comparing the DRC profile in milk of these women with the reported profile in house dust from the same site, dust ingestion was estimated to contribute most of the intake for tetraBDF, 37 per cent to 55 per cent for penta–octaCDFs, but less than twenty per cent for PCDDs and DL-PCBs, and 26 per cent for total WHO-TEQs. The DL activities in some EWRS milk samples were not fully explained by chemical data, suggesting contribution from unidentified compounds. The estimated WHO-TEQ intake doses for breastfed infants (1.3–33pg/kg/d) mostly exceeded the tolerable value, especially for those living in the EWRSs; and unidentified DRCs might increase further the dioxin-related health risk. [Copyright &y& Elsevier]

The aim of this study was to clarify the relationship between dioxin concentrations in breast milk and the sister chromatid exchange (SCE) frequency in women from herbicide-sprayed and non sprayed areas. Blood samples were taken from 21 women with high TCDD (tetrachlorodibenzo-p-dioxin) levels from sprayed areas, 23 women with moderate TCDD levels from sprayed areas, and 19 women from non sprayed areas to determine their SCE frequency. The SCE frequencies for the high and moderate TCDD groups from the sprayed area and for the non sprayed area group were 2.40, 2.19, and 1.48 per cell, respectively. Multiple regression analysis showed that the standardized ß values for 1,2,3,6,7,8-hexaCDD (ß = 0.60), 1,2,3,4,6,7,8-heptaCDD (ß = 0.64), and octaCDD (ß = 0.65) were higher than those for TCDD (ß = 0.34) and 1,2,3,7,8-pentaCDD (ß = 0.42). The adjusted R2 value for polyCDDs (R2 = 0.38) was higher than that for polyCDD toxic equivalents (TEQ (toxic equivalents); R2 = 0.23). This study therefore shows that levels of hexa-, hepta-, and octaCDD, which were previously regarded as being less toxic than TCDD, are closely related to SCE frequency and that the level of dioxin (pg/g lipid) is potentially more useful as an indicator than TEQ value for explaining SCE frequency. [ABSTRACT FROM AUTHOR]

In many countries, girls have been reported to be less often admitted to hospital than boys. We studied the influence of socio-economic factors, education and access to health care on girls’ and boys’ admission rates for pneumonia, diarrhoea and dengue fever in south-central Vietnam. We explored whether the user fee exemption for children under 6 years introduced in 2005 had an impact on girls’ admission rates.In a cohort analysis, we used data from a large census in Khanh Hoa Province conducted in 2006, linked to hospital admission records at individual level. We further analysed a cross-sectional health care utilization survey in a sample of children reported ill at the census. There were 38 731 children under 6 years among a total census population of 353 891. Overall, girls under the age of 6 years were 29% less likely to be admitted to hospital than boys. The gender differences in admission rates in children under 6 years were similar for diarrhoea, pneumonia and dengue. None of the socio-economic and educational factors appeared to affect the gender difference. The user fee exemption starting from October 2005 had no impact on the girls/boys rate ratio of admission. In conclusion, the higher hospital admission rates of boys compared with girls in Vietnam are independent of socio-economic factors and user fees. Higher susceptibility of boys to severe disease could explain part of the gender gap, but profound cultural norms and beliefs may also have contributed to the findings. [ABSTRACT FROM PUBLISHER]

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Parenting practices are known to vary across different sociocultural settings, but there has been little scientific research conducted on parenting intervention in Asia to date. Building on our past research achievements that show a strong need for parenting support, we conducted a pilot trial of systematic screening of Vietnamese mothers with poor mental health and the provision of a group-based parenting program, along with staff training sessions at a university-affiliated general hospital in Ho Chi Minh City. Forty-seven first-time mothers attending routine child health checkups were screened using a brief mental health and parenting assessment tool that we had developed and used previously. We then evaluated a group-based parenting program provided for two consecutive days to nine participants. The framework of the Canadian Nobody's Perfect Program, which we had previously adopted and evaluated in a Japanese public health service setting, was used to develop a Vietnamese version. The screening and program were found to be well accepted by both participants and staff and are considered to be feasible for use by public hospital services in Vietnam. The process of program adaptation described and discussed herein may be useful to other health professionals in the Asia- Pacific region undertaking similar initiatives. [ABSTRACT FROM AUTHOR]

Introduction Postnatal depression is a serious mental health problem. In low-income countries, there has been only limited research investigating the direct link between childrearing attitude and maternal mood. The present study sought to determine the prevalence of probable depressive state among mothers in Vietnam, and to examine its risk factors with respect to social support and maternal childrearing attitude. Methods A questionnaire survey was conducted in 299 consecutive mothers who visited Tu Du Obstetrical and Gynecological Hospital, a tertiary hospital, for regular check-up between one and three months postpartum. The questionnaire was administered by trained pediatricians in October through December 2007. Depression was assessed using a two-question case-finding instrument for depression. Results Sixty-eight of the 294 (23.1%) mothers of singletons were assessed as having probable depressive state. Parental and familial conflict and recent moving was strongly associated with probable depressive state. In terms of childrearing attitude, the following factors increased risk of probable depressive state of mothers; lack of confidence (adjusted odds ratio = 2.74, 95% confidence interval: 1.40-5.38), and less relaxed feeing (adjusted odds ratio = 2.85, 95% confidence interval: 1.21-6.71) after controlling for subjective health. Discussion Mothers who felt unconfident and were less relaxed in childrearing were more likely to report a probable depressive state. Social support factors may have played a role in the depression. A brief screening tool for depression is useful to identify mothers in need of additional support in childrearing. [ABSTRACT FROM AUTHOR]

Background: Aedes aegypti, the major vector of dengue viruses, often breeds in water storage containers used by households without tap water supply, and occurs in high numbers even in dense urban areas. We analysed the interaction between human population density and lack of tap water as a cause of dengue fever outbreaks with the aim of identifying geographic areas at highest risk. Methods and Findings: We conducted an individual-level cohort study in a population of 75,000 geo-referenced households in Vietnam over the course of two epidemics, on the basis of dengue hospital admissions (n = 3,013). We applied space-time scan statistics and mathematical models to confirm the findings. We identified a surprisingly narrow range of critical human population densities between around 3,000 to 7,000 people/km2 prone to dengue outbreaks. In the study area, this population density was typical of villages and some peri-urban areas. Scan statistics showed that areas with a high population density or adequate water supply did not experience severe outbreaks. The risk of dengue was higher in rural than in urban areas, largely explained by lack of piped water supply, and in human population densities more often falling within the critical range. Mathematical modeling suggests that simple assumptions regarding area-level vector/host ratios may explain the occurrence of outbreaks. Conclusions: Rural areas may contribute at least as much to the dissemination of dengue fever as cities. Improving water supply and vector control in areas with a human population density critical for dengue transmission could increase the efficiency of control efforts. [ABSTRACT FROM AUTHOR]

Few studies have investigated the human exposure to the ensemble of dioxin-related compounds (DRCs) released from uncontrolled e-waste recycling, especially from a toxic effect standpoint. This study evaluated the TCDD toxic equivalents (TEQs) in persistent extracts of settled house dust from two Vietnamese e-waste recycling sites (EWRSs) using the Dioxin-Responsive Chemically Activated LUciferase gene eXpression assay (DR-CALUX), combined with chemical analysis of PCDD/Fs, DL-PCBs, PBDD/Fs, and monobromo PCDD/Fs to determine their TEQ contribution. The CALUX-TEQ levels in house dust ranged from 370 to 1000 pg g-1 in the EWRSs, approximately 3.5-fold higher than in the urban control site. In EWRS house dust, the concentrations of the unregulated PBDFs were 7.7-63 ng g-1, an order of magnitude higher than those of regulated DRCs (PCDD/Fs and DL-PCBs), and PBDFs were also principal CALUX-TEQ contributors (4.2-22%), comparable to PCDD/Fs (8.1-29%). The CALUX-TEQ contribution of DRCs varied, possibly depending on thermal processing activities (higher PCDD/F-TEQs) and PBDE content in the waste (higher PBDF-TEQs). However, the percentage of unknown dioxin-like activities was high in all dust samples, indicating large contribution from unidentified DRCs and/or synergy among contaminants. Estimates of TEQ intake from dust ingestion suggest that children in the EWRSs may be adversely affected by DRCs from dust. [ABSTRACT FROM AUTHOR]

There is a great deal of concern regarding the adverse effects of polychlorinated dibenzodioxins (PCDD) and polychlorinated dibenzofurans (PCDF) present in Agent Orange and other herbicides on Vietnam's population and ecosystems. The purpose of this study was to determine the effect of dioxin exposure on adrenal steroids in saliva, and dioxin levels in breast milk, of primiparas in an Agent Orange/dioxin hot-spot and a non-exposed area in Vietnam on the basis of epidemiological research. The subjects were 35 lactating women who had recently given birth to their first or second child. A further sub-study involved eight primiparas from each area. All subjects were aged between 20 and 30 years with infants aged between 4 and 16 weeks. The mean concentration of PCDD, PCDF, and PCDD + PCDF toxic equivalents (TEQ) in breast milk in the hot-spot area was significantly higher than in the non-exposed area. Cortisol and cortisone levels in the saliva of primiparas in the hot-spot area were also significantly higher than those in the non-exposed area. There was a significant negative correlation between cortisol and the cortisol/cortisone ratio and PCDD + PCDF and PCDF TEQ levels in the hot-spot area. Furthermore, the correlation between cortisol and cortisone and the PCDD + PCDF, PCDD, and PCDF TEQ in the combination of hot spot + non-exposed area was significant according to the curve (bell style). Our results suggest that Agent Orange/dioxin exposure still exerts a major influence on the salivary hormones of the Vietnamese population. [ABSTRACT FROM AUTHOR]

A clinical picture of patients with acute respiratory distress syndrome (ARDS) induced by highly pathogenic avian influenza A (H5N1) has been reported. We reviewed 37 sets of clinical data for pediatric patients with ARDS at the National Hospital of Pediatrics (Hanoi, Vietnam); 12 patients with H5N1-positive and 25 with H5N1-negative ARDS were enrolled. The H5N1-negative patients had a clinical picture and mortality rate similar to that for the pediatric ARDS patients. However, the H5N1-positive patients had ARDS with normal ventilation capacity at the time of hospital admission, then rapidly proceeded to severe respiratory failure. The survival probability and days until final outcome in groups of H5N1-positive (n=12) vs. H5N1-negative (n=25) patients were 17% versus 52% and 12.3±5.7 days (median, 11 days) versus 21.5±13.8 days (median, 22 days), respectively. Our observations clarified the clinical picture of H5N1-induced fulminant ARDS and also confirmed that relatively older age (~6 years of age), high fever at onset, and leukopenia and/or thrombocytopenia at the time of hospital admission are risk parameters for H5N1-induced fulminant ARDS. [ABSTRACT FROM AUTHOR]

The objective of this field questionnaire survey was to provide information about the characteristics of rural smallholder farming communities, which have been targeted by the Vietnamese government's dairy development policy. The results from this study suggest that the adoption of dairy farming is partly determined by pre-existing wealth of the farming households. It is, therefore, more likely that while the government's dairy development policy has achieved its first objective of an increase in the dairy cattle population, it has been less successful at achieving the second objective of reducing the level of poverty within rural areas. [ABSTRACT FROM AUTHOR]

The objective of the study was to investigate constraints to dairy cattle health and production in rural smallholder communities in northern Vietnam, one of the target areas of the Vietnam government's dairy development programme. A total of 99 dairy farms (11 per commune) were recruited from 9 of 32 communes in Ba Vi District, using random two-stage cluster sampling. After the initial questionnaire interviews were conducted, farms were visited at three monthly intervals over a period of 1 year. Information on several health and production parameters relating to the study cattle was collected. Using multiple indicator modelling, it was found that Fasciola infestation, farmers who had been involved in dairying for longer (not indicative of better management skills), larger herd size, and cattle being kept in a shed were linked to reduced reproductive performances. [ABSTRACT FROM AUTHOR]

The article reports on the results of a study of inter-subspecies hybrid dikaryons of oyster mushroom independently isolated in Vietnam and Japan. A description of the experimental set-up and measurement methods is presented. The study concluded that the asexual reproduction might allow stable maintenance of a particular pair of nuclei.

• Network-based targeting has a positive effect on the treated farmers' knowledge. • Network-based targeting group shares information with more neighbors. • Network-based targeting has a spillover effect on untreated farmers' knowledge. In developing countries, social networks play a critical role in the transmission of information about new technologies and influence an individual's decision to adopt the technology. Thus, this study considered a case of shrimp farmers in Vietnam to identify whether the farmers' networks have positive effects on diffusing accurate agricultural information to the treated farmers and their neighbors. To explore the effects, we invited farmers selected using network-based targeting to a workshop held in December 2017 and estimated it using data obtained before and after the treatment. We found that: 1) the targeting has a positive effect on the treated farmers' knowledge level about a good aquaculture practice; 2) The treated farmers selected using the network-based targeting share information with more neighbors when they get new information; and 3) The targeting has a positive spillover effect on untreated farmers' knowledge level, but its effect is lower than other randomly selected. These findings can conclude that network-based targeting appears to be a method to disseminate information to many people. Nevertheless, the methods are less likely to deliver accurate information to a wider group of farmers than random sampling. [ABSTRACT FROM AUTHOR]

The microbial degradation of synthetic and natural poly(cis -1,4-isoprene) rubber is expected to become an alternative treatment technique for waste from poly(cis -1,4-isoprene) products, such as scrap tires. A gram-positive rubber-degrading bacterium, Rhodococcus sp. strain RDE2, was isolated from the waste of a rubber-processing factory in Vietnam. This strain grew on natural rubber as a sole source of carbon and energy and produced oligo-isoprenoid metabolites containing aldehyde groups from poly(cis -1,4-isoprene). To identify the genes responsible for poly(cis -1,4-isoprene) degradation, the complete genome sequence of this strain was determined. The complete genome sequence consists of a 5,715,406 bp chromosome and 6 plasmids (GenBank accession numbers AP025186.1 to AP025192.1) with an average GC content of 67.9%. The genome contains 5358 protein-coding sequences and 12 and 68 copies of rRNA and tRNA genes, respectively. Based on genome sequence analysis, the lcp gene (RDE2_08,770), responsible for the initial step of poly(cis -1,4-isoprene) degradation, was identified. The gene product obtained from Escherichia coli depolymerizes poly(cis -1,4-isoprene) to low-molecular-weight oligo-isoprenoids. The transcription of this gene is activated during the utilization of poly(cis -1,4-isoprene) in strain RDE2. The lcpR gene (RDE2_08,760), which encodes a putative transcriptional regulator, is located upstream of lcp. The lcpR gene product recognizes the promoter region of lcp. When the lcpR gene is deleted, the constitutive transcription of lcp is observed. Thus, it is inferred that the LcpR negatively regulates lcp transcription. These results strongly suggest that the lcp and lcpR genes are involved in poly(cis -1,4-isoprene) utilization in strain RDE2. [ABSTRACT FROM AUTHOR]

Ciguatera fish poisoning (CFP) is a type of food poisoning caused by the consumption of a variety of toxic ciguatera fish species in the tropical and subtropical waters. Although there have been a large number of suspected CFP cases in the Southeast Asian countries, few were confirmed with causative ciguatoxins (CTXs), and reliable information on the symptoms still remains rather limited. In the present study, CTXs in red snapper Lutjanus bohar, implicated in two suspected CFP cases in Vietnam in 2014 and 2016, were determined by use of the single-quadrupole selected ion monitoring (SIM) liquid chromatography/mass spectrometry (LC/MS). Ciguatoxin-1B (CTX-1B), 54-deoxyCTX-1B, and 52-epi-54-deoxyCTX-1B were detected in the red snapper by our LC/MS method. Moreover, CTX-1B, 54-deoxyCTX-1B, and 52-epi-54-deoxyCTX-1B were further identified by the time of flight (TOF) LC/MS with the exact mass spectrum. The CTX profile of the red snapper in Vietnam is similar to those of ciguatera fish from Australia, Okinawa Islands in Japan, Kiribati, and Hong Kong. This is the first comprehensive report unambiguously identifying the causative toxins in fish implicated with reliable information on the poisoning symptoms in CFP in Vietnam and/or Southeast Asian countries. [ABSTRACT FROM AUTHOR]

• Pre-existing immunity against recent SARS-CoV-2 strains in Vietnam was determined. • Pre-COVID-19 samples neutralize Wuhan and Alpha strains but not newer variants. • Limited cellular immunity to SARS-CoV-2 suggests a lack of cross-immunity among newer variants of concern. • Pre-COVID-19 immunity may influence low transmission in the early phase of a pandemic. SARS-CoV-2 transmission and epidemic potential is related to the population's immunity levels. As such, assessing different regions' preexisting immune responses to SARS-CoV-2 is important to understand the transmission potential of emerging SARS-CoV-2 variants. In 975 serum samples from Vietnam (2014 to 2019), anti-SARS-CoV-2 Immunoglobulin G levels were determined by enzyme-linked immunosorbent assay. Plaque reduction neutralization test (PRNT) was performed using Wuhan strain and variants of concern (VOCs). Cross-reactivity was confirmed by analyzing B-cell receptor (BCR) repertoire sequences and identifying BCR repertoire sequences-derived T-cell epitopes. Overall, 20.9% (n = 76/364) and 9.2% (n = 7) demonstrated SARS-CoV-2 neutralizing activity (PRNT 50) against the Wuhan and Alpha strain, respectively. Neutralizing activity against Beta, Gamma, and Delta strains was absent (PRNT 50 <5) in all samples. Cross-reactive epitopes against SARS-CoV-2 and other coronavirus spike proteins were detected in the N-terminal domain, S2, and receptor-binding domain regions. Following BCR and major histocompatibility complex analysis, T-cell receptor-recognized epitope motif (TREM) among pathogenic coronaviruses and coronaviruses spike proteins were the top TREM peptide, suggesting that pre-existing immunity against SARS-CoV-2 in Vietnam was due to exposure to common cold coronaviruses. With limited immunity against emerging VOCs, further monitoring, and control of the epidemic, along with COVID-19 vaccine programs against VOCs, are necessary. [ABSTRACT FROM AUTHOR]

Abstract: This study investigated the occurrence of polychlorinated biphenyls (PCBs), and several additive brominated flame retardants (BFRs) in indoor dust and air from two Vietnamese informal e-waste recycling sites (EWRSs) and an urban site in order to assess the relevance of these media for human exposure. The levels of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), 1,2-bis-(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenyl ethane (DBDPE) in settled house dust from the EWRSs (130–12,000, 5.4–400, 5.2–620 and 31–1400ngg−1, respectively) were significantly higher than in urban house dust but the levels of PCBs (4.8–320ngg−1) were not higher. The levels of PCBs and PBDEs in air at e-waste recycling houses (1000–1800 and 620–720pgm−3, respectively), determined using passive sampling, were also higher compared with non-e-waste houses. The composition of BFRs in EWRS samples suggests the influence from high-temperature processes and occurrence of waste materials containing older BFR formulations. Results of daily intake estimation for e-waste recycling workers are in good agreement with the accumulation patterns previously observed in human milk and indicate that dust ingestion contributes a large portion of the PBDE intake (60%–88%), and air inhalation to the low-chlorinated PCB intake (>80% for triCBs) due to their high levels in dust and air, respectively. Further investigation of both indoor dust and air as the exposure media for other e-waste recycling-related contaminants and assessment of health risk associated with exposure to these contaminant mixtures is necessary. [Copyright &y& Elsevier]

Objective To examine the association between gestational weight gain and maternal body mass index (BMI) among Vietnamese women and the risk of delivering an infant too small or too large for gestational age. Methods A prospective health-facility-based study of 2989 pregnant Vietnamese women was conducted in the city of Nha Trang in 2007-2008. Cubic logistic regression was used to investigate the association of interest. Infants were classified into weight-for- gestational-age categories according to weight centiles for the Asian population. Gestational age was based on the date of last menstrual period and adjusted by the results of first-trimester ultrasound. Findings BMI was low (< 18.5), normal (18.5-22.9) and high (≥23.0) in 26.1%, 65.4% and 8.5% of the women, respectively. In each of these BMI categories, the percentage of women who delivered infants too small for gestational age was 18.1, 10.0 and 9.4, respectively, and the mean gestational weight gain was 12.5 kg (standard deviation, SD:±3.6), 12.2 kg (SD:±3.8) and 11.5 kg (SD:±4.7), respectively. Among women with low BMI, the risk of delivering an infant too small for gestational age ranged from approximately 40% if the gestational weight gain was < 5 kg to 20% if it was 5-10 kg. Conclusion Having a low BMI, commonly found in Viet Nam, puts women at risk of delivering an infant too small for gestational age, especially when total maternal gestational weight gain is < 10 kg. [ABSTRACT FROM AUTHOR]

Abstract: A suite of picrites and basalts from the Muli area, in the northwestern part of the Emeishan continental flood basalt province, provides new and valuable information on the geochemistry of the Emeishan Large Igneous Province (LIP) and its source. The Muli picrites can be classified as type-1 or type-2. The former shows ocean–island basalt-like trace element characteristics, with γOs (260Ma) values and εNd (260Ma) values ranging from +7.5 to +11.5 and from +6.0 to +7.8, respectively. This is the first time that picrites with highly radiogenic Os and high Os contents (up to 3.3ppb) have been recognized in the Emeishan LIP. These characteristics probably reflect a relatively enriched component in the Emeishan LIP source. The type-2 picrites are characterized by non-radiogenic γOs (260Ma) values ranging from −4.2 to −0.3, and they may be further subdivided into type-2A and type-2B picrites. Type-2A picrites contain moderate amounts of the light rare earth elements (LREEs), have low CeN/YbN values (1.1–2.0), and a relatively high initial εNd (+5.0 to +6.6). In terms of Os and Nd isotopes, the Muli type-2A picrites are similar to the Song Da komatiites of Vietnam and the Gorgona Island picrites, revealing the existence of a depleted mantle component in the Emeishan LIP source. In contrast with the type-2A picrites, type-2B lavas exhibit a negative Nb anomaly and relatively lower initial εNd and γOs values (Nb/La>1.8; εNd (260Ma)=−5.5 to +6.4; γOs (260Ma)=−4.2 to −1.9), suggesting that the type-2B lavas have a depleted mantle source, similar to type-2A, but that the type-2B lavas are also influenced by various degrees of mixing of depleted plume-derived melt, sub-continental lithospheric mantle, and/or continental crust. Given that the basalts in the Muli area show similar geochemical features to those of the type-2B picrites, their origins are inferred to be similar. [Copyright &y& Elsevier]

• Prevalence of childhood otitis media with effusion; 17% before pneumococcal vaccine. • Pneumococcus carriage and otitis media was associated among children under one. • Daycare attendance and rural residence were positively associated with otitis media. • Further studies after introducing pneumococcal vaccines are required. Otitis media with effusion (OME) commonly occurs and persists in young children. It can cause hearing impairment and damage to the tympanic membrane without treatment. We aimed to determine the prevalence and association of Streptococcus pneumoniae in the nasopharynx of healthy children before the introduction of a pneumococcal conjugate vaccine. In October 2016, nasopharyngeal swabs collection and otoscope examinations by an otolaryngologist were conducted in children aged less than 24 months in Nha Trang, Vietnam. OME was diagnosed as the presence of middle ear fluid using a digital otoscope equipped with a pneumatic otoscope. Quantitative PCR targeting pneumococci-specific lytA (the major autolysis gene) and bacterial culture were performed to detect S. pneumoniae. The point prevalence of OME in the study area was estimated. The association between OME and S. pneumoniae in the nasopharynx was evaluated using a multivariable logistic regression model. Among the 274 children who underwent bilateral ear examinations and nasopharyngeal swab collections, 47 had OME (17.2%, 95% confidence interval [CI] 12.9–22.1%) and 96 were colonized with S. pneumoniae (35.0%, 29.4–41.0%). OME and nasopharyngeal S. pneumoniae carriage were positively associated in children aged less than 12 months (adjusted odds ratio [aOR] 3.83, 1.40–10.51). Day-care attendance and living in a rural area were independently associated with OME (aOR 5.87, 2.31–14.91, and aOR 3.77, 1.58–8.99, respectively). The nasopharyngeal pneumococcal carriage was associated with OME among children aged <12 months. A further study after introducing a pneumococcal conjugate vaccine (PCV) is required to better understand the effect of PCV and S. pneumoniae carriage on OME in young children. [ABSTRACT FROM AUTHOR]

This study proposes a new monitoring method to measure real-time aerosol chloride deposition. The concept of a water candle device is introduced, and the device is manufactured. By continuously generating a thin water film in combination with a conductivity sensor, the device is capable of measuring aerosol chloride deposition in all directions and has a compact design. The water candle device was fully tested in the laboratory and applied to monitor on a bridge. For the laboratory tests, the transport of aerosol in an area near the seashore was simulated to evaluate the accuracy and responsiveness of the device according to the variable wind speed and source salt concentration. For monitoring in the field, the device was implemented at the Thuan Phuoc Bridge, Vietnam, for seven days with a short recording frequency of a few hours. A set of wet candle devices were placed next to the water candle device to compare the results of the two methods. The results of the laboratory test and field monitoring demonstrated a high accuracy and responsiveness of the water candle device to variations in the wind speed and salt concentration of the source. Further, there were only very small differences between the results from the wet and water candle devices. • Real-time aerosol chloride deposition measuring device was proposed and manufactured. • Water candle device can measure low chloride content up to 0.1 × 10-6 mol L-1. • The measured result differences between the water and wet candle devices were small. • Water candle device performed a good match with variable wind speed. [ABSTRACT FROM AUTHOR]

Introduction Despite the global success of Hib vaccination in reducing disease and mortality, uncertainty about the disease burden and the potential impact of Hib vaccination in Southeast Asia has delayed the introduction of vaccination in some countries in the region. Hib vaccination was introduced throughout Vietnam in July 2010 without catch-up. In an observational, population based surveillance study we estimated the impact of routine Hib vaccination on all cause radiologically confirmed childhood pneumonia in Nha Trang, Vietnam. Materials and methods In 2007 active hospital based surveillance was established in Khanh Hoa General Hospital, the only hospital in Nha Trang, Khanh Hoa province. Nasopharyngeal samples and chest radiographs are taken routinely from all children diagnosed with acute respiratory illness on admission. For admissions between 02/2007 and 03/2012 chest radiographs were interpreted for the presence of WHO primary endpoint pneumonia and nasopharyngeal swabs were analysed by PCR for the presence of Influenza A or B, RSV and rhinovirus. We employed Poisson regression to estimate the impact of Hib vaccination on radiologically confirmed pneumonia (RCP) while statistically accounting for potential differences in viral circulation in the post vaccination era which could have biased the estimate. Results Of 3151 cases admitted during the study period, 166 had RCP and major viruses were detected in 1601. The adjusted annual incidence of RCP in children younger than 5 years declined by 39% (12–58%) after introduction of Hib vaccination. This decline was most pronounced in children less than 2 years old, adjusted IRR: 0.52 (0.33–0.81), and no significant impact was observed in the 2–4 years old who were not eligible for vaccination, adjusted IRR: 0.96 (0.52–1.72). Discussion We present early evidence that the burden of Hib associated RCP in Nha Trang before vaccination was substantial and that shortly after introduction to the routine childhood immunisation scheme vaccination has substantially reduced that burden. [ABSTRACT FROM AUTHOR]

To assess the presence and distribution of the sul genes (sul1, sul2, and sul3) and plasmids in human-mediated environments of north Vietnam, we examined a total of 127 sulfonamide-resistant (SR) bacterial isolates from four shrimp ponds (HNAQs), a city canal (HNCs) and three fish ponds that received wastewater directly from swine farms (HNPs). Results from the SR isolates revealed that sul genes were most frequently detected in the HNPs (92.0%), followed by HNCs (72.0%), and the HNAQs (43.0%). Among the sul genes detected, sul1 was the most prevalent gene in all three environments (57.0, 33.0 and 60.0% in HNPs, HNAQs, and HNCs, respectively) followed by sul2 (51.0, 19.0, and 20.0%, respectively) and sul3 (14.0, 6.0, and 8.0%, respectively). All combinations of paired different sul genes were detected, with the combination between sul1 and sul2 being the most frequent in all three environments (20.0, 8.0, and 8.0% in HNPs, HNAQs, and HNCs, respectively). The combination of three sul genes was detected at low frequencies (2–3%) in the HNPs and HNAQs, and was absent in the HNCs. The sul genes were more frequently located on the chromosome than on plasmids. The identification of SR isolates positive for the sul genes and plasmids showed that Acinetobacter was the most dominant. Our study revealed that the sul genes were common in SR bacteria from the aquatic environments we examined from northern Vietnam. Wastewater from swine farms might be “hot spots” of the sul genes and plasmids and may be reservoirs for the exchange of the sul genes among bacteria. [Copyright &y& Elsevier]

It is essential to increase the production of foods to meet the increasing future food demand, but this should be done in an environmentally sustainable manner. Integrated crop-livestock systems have been suggested to balance the reduction of environmental impacts and the increase in food production. Here we assessed and compared the environmental impacts of specialized (SPC) and integrated (ITG) rice and beef production systems in the Mekong Delta, Vietnam, using a life-cycle assessment (LCA). The productions of rice and beef are separated in the SPC, whereas they are integrated in the ITG: cattle manure is treated by a biodigester for biogas production, its digestate is applied to rice paddy fields as fertilizer, and part of the rice straw is used as cattle feed. We developed an LCA model based on data collected by site investigations of rice and beef farms and the relevant literature and LCA databases. Our evaluation of the ITG and SPC rice-beef production systems using the LCA revealed that among the four environmental impact categories investigated herein, the ITG had less environmental impacts on climate change (22%), energy consumption (22%), and eutrophication (14%) compared to the SPC. With the ITG, the reduction of methane emissions from paddy fields, the avoided energy consumption by the biogas produced, and the lower ammonia, nitrate, and phosphorous emissions from cattle manure and no eutrophying pollutant emissions from grassland were the main contributors to the lower greenhouse gas emissions, energy consumption, and eutrophication potential of this system, respectively. A sensitivity analysis showed that the use of cover for digestate storage resulted in lower environmental impacts of the ITG system compared to SPC system in all of the impact categories investigated here. These results provide helpful information to develop a circular and resource-efficient rice and beef production system that balances increasing productivity with environmental sustainability in rice-producing countries, particularly in Asia. • Life cycle assessment on specialized and integrated rice and beef production systems. • Site investigations of 35 rice and beef farms were conducted in Mekong Delta, Vietnam. • Manure treatment by a biodigester and feed use of rice straw in the integrated system. • The integrated system has lower greenhouse gas emissions and other environmental impacts. • The use of cover for digestate storage leads to lower acidification potential. [ABSTRACT FROM AUTHOR]