Objective: In Viet Nam, tuberculosis (TB) prevalence surveys revealed that approximately 98% of individuals with pulmonary TB have TB-presumptive abnormalities on chest radiographs, while 32% have no TB symptoms. This prompted the adoption of the “Double X” strategy, which combines chest radiographs and computer-aided detection with GeneXpert testing to screen for and diagnose TB among vulnerable populations. The aim of this study was to describe demographic, clinical and radiographic characteristics of symptomatic and asymptomatic Double X participants and to assess multilabel radiographic abnormalities on chest radiographs, interpreted by computer-aided detection software, as a possible tool for detecting TB-presumptive abnormalities, particularly for subclinical TB. Methods: Double X participants with TB-presumptive chest radiographs and/or TB symptoms and known risks were referred for confirmatory GeneXpert testing. The demographic and clinical characteristics of all Double X participants and the subset with confirmed TB were summarized. Univariate and multivariable logistic regression modelling was used to evaluate associations between participant characteristics and subclinical TB and between computer-aided detection multilabel radiographic abnormalities and TB. Results: From 2020 to 2022, 96 631 participants received chest radiographs, with 67 881 (70.2%) reporting no TB symptoms. Among 1144 individuals with Xpert-confirmed TB, 51.0% were subclinical. Subclinical TB prevalence was higher in older age groups, non-smokers, those previously treated for TB and the northern region. Among 11 computer-aided detection multilabel radiographic abnormalities, fibrosis was associated with higher odds of subclinical TB. Discussion: In Viet Nam, Double X community case finding detected pulmonary TB, including subclinical TB. Computer-aided detection software may have the potential to identify subclinical TB on chest radiographs by classifying multilabel radiographic abnormalities, but further research is needed.

Curcuma zedoaria (Christm.) Rosc. is a popular traditional herb to treat digestive disorders in Asian tropical countries. Previous studies indicated the presence of sesquiterpenoids, diterpenoids, and curcuminoids with various bioactivities. To enrich the phytocomposition data of this plant, this investigation was conducted.The dried rhizomes of C. zedoaria were collected in Hai Phong City (Vietnam), extracted with methanol and fractionated with n-hexane, CH2Cl2 , and EtOAc. Compounds were isolated from n-hexane soluble fraction by open column chromatography combined with thin layer chromatography from fraction n-hexane. Their chemical structures were elucidated by 1D, and 2D NMR spectra and comparison with reported data. As a result, a phytochemical investigation was conducted to isolate six sesquiterpenes from C. zedoaria. Their chemical structures were elucidated to be curcumenol (1), procurcumenol (2), neoprocurcumenol (3), 13-hydroxygermacrone (4), zederone (5), and curcumalactone (6). Among isolated compounds, compounds 1, 2, 4, and 5 were reported from C. zedoaria. Meanwhile, neoprocurcumenol (3) and curcumalactone (6) are isolated from this species for the first time. Compound 5 exhibited a mild inhibitory effect on α-glucosidase with an IC50 of 99.45 ± 0.50 μg/mL.

Curcuma zedoaria (Christm.) Rosc. is a popular traditional herb to treat digestive disorders in Asian tropical countries. Previous studies indicated the presence of sesquiterpenoids, diterpenoids, and curcuminoids with various bioactivities. To enrich the phytocomposition data of this plant, this investigation was conducted.The dried rhizomes of C. zedoaria were collected in Hai Phong City (Vietnam), extracted with methanol and fractionated with n-hexane, CH2Cl2 , and EtOAc. Compounds were isolated from n-hexane soluble fraction by open column chromatography combined with thin layer chromatography from fraction n-hexane. Their chemical structures were elucidated by 1D, and 2D NMR spectra and comparison with reported data. As a result, a phytochemical investigation was conducted to isolate six sesquiterpenes from C. zedoaria. Their chemical structures were elucidated to be curcumenol (1), procurcumenol (2), neoprocurcumenol (3), 13-hydroxygermacrone (4), zederone (5), and curcumalactone (6). Among isolated compounds, compounds 1, 2, 4, and 5 were reported from C. zedoaria. Meanwhile, neoprocurcumenol (3) and curcumalactone (6) are isolated from this species for the first time. Compound 5 exhibited a mild inhibitory effect on α-glucosidase with an IC50 of 99.45 ± 0.50 μg/mL.

Curcuma zedoaria (Christm.) Rosc. is a popular traditional herb to treat digestive disorders in Asian tropical countries. Previous studies indicated the presence of sesquiterpenoids, diterpenoids, and curcuminoids with various bioactivities. To enrich the phytocomposition data of this plant, this investigation was conducted.The dried rhizomes of C. zedoaria were collected in Hai Phong City (Vietnam), extracted with methanol and fractionated with n-hexane, CH2Cl2 , and EtOAc. Compounds were isolated from n-hexane soluble fraction by open column chromatography combined with thin layer chromatography from fraction n-hexane. Their chemical structures were elucidated by 1D, and 2D NMR spectra and comparison with reported data. As a result, a phytochemical investigation was conducted to isolate six sesquiterpenes from C. zedoaria. Their chemical structures were elucidated to be curcumenol (1), procurcumenol (2), neoprocurcumenol (3), 13-hydroxygermacrone (4), zederone (5), and curcumalactone (6). Among isolated compounds, compounds 1, 2, 4, and 5 were reported from C. zedoaria. Meanwhile, neoprocurcumenol (3) and curcumalactone (6) are isolated from this species for the first time. Compound 5 exhibited a mild inhibitory effect on α-glucosidase with an IC50 of 99.45 ± 0.50 μg/mL.

Curcuma zedoaria (Christm.) Rosc. is a popular traditional herb to treat digestive disorders in Asian tropical countries. Previous studies indicated the presence of sesquiterpenoids, diterpenoids, and curcuminoids with various bioactivities. To enrich the phytocomposition data of this plant, this investigation was conducted.The dried rhizomes of C. zedoaria were collected in Hai Phong City (Vietnam), extracted with methanol and fractionated with n-hexane, CH2Cl2 , and EtOAc. Compounds were isolated from n-hexane soluble fraction by open column chromatography combined with thin layer chromatography from fraction n-hexane. Their chemical structures were elucidated by 1D, and 2D NMR spectra and comparison with reported data. As a result, a phytochemical investigation was conducted to isolate six sesquiterpenes from C. zedoaria. Their chemical structures were elucidated to be curcumenol (1), procurcumenol (2), neoprocurcumenol (3), 13-hydroxygermacrone (4), zederone (5), and curcumalactone (6). Among isolated compounds, compounds 1, 2, 4, and 5 were reported from C. zedoaria. Meanwhile, neoprocurcumenol (3) and curcumalactone (6) are isolated from this species for the first time. Compound 5 exhibited a mild inhibitory effect on α-glucosidase with an IC50 of 99.45 ± 0.50 μg/mL.

Curcuma zedoaria (Christm.) Rosc. is a popular traditional herb to treat digestive disorders in Asian tropical countries. Previous studies indicated the presence of sesquiterpenoids, diterpenoids, and curcuminoids with various bioactivities. To enrich the phytocomposition data of this plant, this investigation was conducted.The dried rhizomes of C. zedoaria were collected in Hai Phong City (Vietnam), extracted with methanol and fractionated with n-hexane, CH2Cl2 , and EtOAc. Compounds were isolated from n-hexane soluble fraction by open column chromatography combined with thin layer chromatography from fraction n-hexane. Their chemical structures were elucidated by 1D, and 2D NMR spectra and comparison with reported data. As a result, a phytochemical investigation was conducted to isolate six sesquiterpenes from C. zedoaria. Their chemical structures were elucidated to be curcumenol (1), procurcumenol (2), neoprocurcumenol (3), 13-hydroxygermacrone (4), zederone (5), and curcumalactone (6). Among isolated compounds, compounds 1, 2, 4, and 5 were reported from C. zedoaria. Meanwhile, neoprocurcumenol (3) and curcumalactone (6) are isolated from this species for the first time. Compound 5 exhibited a mild inhibitory effect on α-glucosidase with an IC50 of 99.45 ± 0.50 μg/mL.

Objective: Human respiratory syncytial virus (RSV) is a primary cause of paediatric severe acute respiratory infection (SARI) worldwide, especially in developing countries. We investigated the genetic characteristics of RSV in northern Viet Nam to determine the prevalence and distribution of subtypes as well as the diversity and transmission patterns of genotypes. Methods: In two facilities, from January 2017 to December 2020, 1563 clinical specimens were collected from paediatric patients hospitalized with SARI and tested for RSV. Selected positive samples underwent sequencing analysis targeting the second hypervariable region of the G gene using next-generation sequencing. Results: The RSV positivity rate was 28.02% (438/1563 samples), and prevalence was highest in children aged <1 year (43.84%; 192/438). Subtype RSV-A accounted for 53.42% (234/438) of cases, RSV-B for 45.89% (201/438), and there was coinfection in 0.68% (3/438). Both subtypes cocirculated and peaked during August–September in each year of the study. Phylogenetic analysis showed that RSV-A samples belonged to the ON1 genotype, which has three subgenotypes: ON1.1, ON1.2 and ON1.3. However, we did not find the 72-nucleotide duplication in the second hypervariable region of the G gene, a characteristic of genotype ON1, in any RSV-A samples. RSV-B samples belonged to genotype BA9. Discussion: Our results provide additional molecular characterization of RSV infections in Viet Nam. Specially, our study is the first to report the absence of the 72-nucleotide duplication in the G gene of RSV-A genotype ON1 in Viet Nam, which may help in understanding the genetic evolution of RSV and be useful for vaccine development in the future.

Aims: Endophytic bacteria (EB) living inside plant tissues possess different beneficial traits including siderophore production and other plant growth-promoting (PGP) activities. Siderophore-producing EB promote host plant growth by secreting ferrum in iron-deficient conditions. This study screened 19 siderophore producers in vitro, isolated from upland rice roots grown in mountain farms of Tung Village, Nậm Có Commune, Mù Cang Chải District, Yên Bái Province, Vietnam, for PGP traits, including phosphate solubilisation, indole-3-acetic acid (IAA), ammonia, gelatinase, amylase and catalase production. Methodology and results: The bacteria were identified by Matrix assisted Laser Desorption Ionization Time of Flight mass spectrometry (MALDI-TOF MS). All 19 isolates were identified as genera Pseudomonas, Enterobacter, Pantoe, Bacillus, Burkholderia, Staphylococcus, Ralstonia and Cronotacter. The isolates produced catalase and ammonia. The amount of ammonia ranged from 60.74 ± 0.14 to 466.72 ± 0.18 mg/L. Out of the 19 siderophore producers, 17 (89.47%) were able to solubilise phosphate with solubilisation index (PSI) ranging from 1.12 ± 0.07 to 2.14 ± 0.15. The qualitative assays identified 12 isolates (63.15%) positive for IAA production with a tryptophan concentration of 5 mM, whereas 15 (78.94%) and 17 (89.47%) isolates were positive for gelatin and starch hydrolysis, respectively. Especially, 7 isolates were found to be positive for all tested assays in vitro including Pseudomonas rhodesiae (NC2), Enterobacter asburiae (NC50), Pantoea ananatis (NC63), Bacillus cereus (NC64), Burkholderia cenocepacia (NC110), Staphylococcus sciuri (NC112) and Ralstonia pickettii (NC122). Conclusion, significance and impact of study This study serves as crucial findings of multi-trait plant growth-promoting endophytic bacteria isolated from upland rice root in north-western Vietnam. The seven potential isolates positive for all tested assays could be effective PGP bacteria for bio-inoculants.
Oryza--microbiology ; Siderophores ; Plant Growth Regulators ; Vietnam

The Omicron variant caused a surge of infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Viet Nam in early 2022, signalling community transmission. We report on active whole-genome sequencing surveillance of positive SARS-CoV-2 samples collected at that time in northern Viet Nam from international arrivals and community clusters. We used an amplicon protocol developed with 14 polymerase chain reaction products and the Illumina iSeq 100 platform. Overall, 213 nasopharyngeal or throat swabs were analysed, of which 172 samples were identified with the Omicron variant. Of these, 80 samples were collected from community cases in February 2022, among which 59 samples were sublineage BA.2 and one sample was the recombinant XE variant. Our results indicated that Omicron had replaced Delta as the dominant variant in a very short period of time and that continuously conducting active whole-genome sequencing surveillance is necessary in monitoring the evolution and genomic diversity of SARS-CoV-2 in Viet Nam.

Background: Viet Nam confirmed its first case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on 23 January 2020 among travellers from Wuhan, China, and experienced several clusters of community transmission until September. Viet Nam implemented an aggressive testing, isolation, contact tracing and quarantine strategy in response to all laboratory-confirmed cases. We report the results of SARS-CoV-2 testing during the first half of 2020 in northern Viet Nam. Methods: Between January and May 2020, 15 650 upper respiratory tract specimens were collected from 14 470 suspected cases and contacts in northern Viet Nam. All were tested for SARS-CoV-2 by real-time RT-PCR. Individuals with positive specimens were tested every three days until two tests were negative. Positive specimens from 81 individuals were cultured. Results: Among 14 470 tested individuals, 158 (1.1%) cases of SARS-CoV-2 infection were confirmed; 89 were imported and 69 were associated with community transmission. Most patients (122, 77%) had negative results after two tests, while 11 and 4 still tested positive when sampled a third and fourth time, respectively. SARS-CoV-2 was isolated from 29 of 81 specimens (36%) with a cycle threshold (Ct) value <30. Seven patients who tested positive again after testing negative had Ct values >30 and negative cultures. Conclusion Early, widespread testing for SARS-CoV-2 in northern Viet Nam identified very few cases, which, when combined with other aggressive strategies, may have dramatically contained the epidemic. We observed rapid viral clearance and very few positive results after clearance. Large-scale molecular diagnostic testing is a critical part of early detection and containment of COVID-19 in Viet Nam and will remain necessary until vaccination is widely implemented.