Aims: The objective of the study was to isolate bacteriophages and conduct a comprehensive analysis of their potential against Xanthomonas oryzae pv. oryzae (Xoo) strains in the Mekong Delta, Vietnam. Methodology and results: Twelve Xoo strains were isolated from rice fields located in the Mekong Delta, Vietnam. Among these strains, three strains Xoo L019, L020 and L024, showed the highest disease index of bacterial blight. Four phages specific to Xoo were isolated from soil, water and leaf samples, and their morphologies were determined. In a test against 12 Xoo strains, phage L541, MLA23 or W41 could infect 10 of the 12 Xoo strains, while phage LBH01 could infect 8 of the 12 Xoo strains. The stability of the phages to pH, organic solvents, UV-A and UV-B was also evaluated. Conclusion, significance and impact of study The initial characterization of the phages indicates their potential as biocontrol agents against bacterial blight in rice. The study is one of the very first studies about Xoo phages in rice in Vietnam.

Objective: The risk of transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from schoolchildren to their household and the protective effects of vaccination in these settings remain poorly understood. We assessed the transmission dynamics of schoolchildren with SARS-CoV-2 within their households and the protective effects of coronavirus disease (COVID-19) vaccination among household members in Viet Nam. Methods: We estimated the attack rate, vaccine effectiveness and adjusted risk ratio (aRR) of factors associated with SARS-CoV-2 transmission to household contacts of children confirmed to have COVID-19 who attended three schools in Ha Nam, Phu Tho and Thanh Hoa provinces between September and December 2021 using multivariable regression with household-level random effects. Results: This retrospective cohort study included 157 children infected with SARS-CoV-2 and their 540 household contacts. The attack rate among household contacts was 24.6% (133/540). Overall, vaccine effectiveness among household contacts was 39% (95% confidence interval [CI]: -1 to -63), higher among males than females and higher in adults aged >40 years. COVID-19 transmission was greater among female household contacts compared with males (aRR: 1.35, 95% CI: 0.94 to 1.95), although not statistically significant, and highest among those aged 19–39 years (aRR: 2.51, 95% CI: 1.50 to 4.21). Fully vaccinated household contacts had significantly lower infection risk (aRR: 0.46, 95% CI: 0.26 to 0.84). Discussion: We found substantial onward transmission of SARS-CoV-2 from schoolchildren to household members, and older people were more likely to be protected by vaccination. We recommend that schoolchildren and all household members living with schoolchildren receive at least two doses of a COVID-19 vaccine. Recognizing the role of schoolchildren in the onward transmission of COVID-19 is an important lesson learned by Viet Nam that can help not only in managing other outbreaks but also in protecting schoolchildren by predicting the progress of the outbreak and preparing for a timely response.

A new crinane-type alkaloid, 6-epihydroxypowelline (1), together with six known alkaloids, lycorine (2), 2-O-acetyllycorine (3), deacetylbowdensine (4), 1-epideacetylbowdensine (5), 8-demethyl-3-oxomaritidine (6), and (-)-marithamine (7) were isolated from the whole parts of the Crinum latifolium L. in Vietnam. The structure identification of all compounds was determined by 1D, 2D-NMR as well as HR-ESI-MS spectroscopic techniques. The absolute configuration of these compounds was established by the ECD data. In addition, in vitro inhibition of acetylcholinesterase (AChE) activities was assessed for all isolated alkaloids. All alkaloids had AChE inhibitory effects, with IC50 values ranging from 32.65 ± 2.72 to 212.76 ± 8.30 µM and compound 3 displayed the strongest inhibition of AChE, with IC50 values of 32.65 ± 2.72 µM (in comparison to the reference drug, galanthamine, which had an IC50 of 2.40 ± 0.45 µM).

A new crinane-type alkaloid, 6-epihydroxypowelline (1), together with six known alkaloids, lycorine (2), 2-O-acetyllycorine (3), deacetylbowdensine (4), 1-epideacetylbowdensine (5), 8-demethyl-3-oxomaritidine (6), and (-)-marithamine (7) were isolated from the whole parts of the Crinum latifolium L. in Vietnam. The structure identification of all compounds was determined by 1D, 2D-NMR as well as HR-ESI-MS spectroscopic techniques. The absolute configuration of these compounds was established by the ECD data. In addition, in vitro inhibition of acetylcholinesterase (AChE) activities was assessed for all isolated alkaloids. All alkaloids had AChE inhibitory effects, with IC50 values ranging from 32.65 ± 2.72 to 212.76 ± 8.30 µM and compound 3 displayed the strongest inhibition of AChE, with IC50 values of 32.65 ± 2.72 µM (in comparison to the reference drug, galanthamine, which had an IC50 of 2.40 ± 0.45 µM).

A new crinane-type alkaloid, 6-epihydroxypowelline (1), together with six known alkaloids, lycorine (2), 2-O-acetyllycorine (3), deacetylbowdensine (4), 1-epideacetylbowdensine (5), 8-demethyl-3-oxomaritidine (6), and (-)-marithamine (7) were isolated from the whole parts of the Crinum latifolium L. in Vietnam. The structure identification of all compounds was determined by 1D, 2D-NMR as well as HR-ESI-MS spectroscopic techniques. The absolute configuration of these compounds was established by the ECD data. In addition, in vitro inhibition of acetylcholinesterase (AChE) activities was assessed for all isolated alkaloids. All alkaloids had AChE inhibitory effects, with IC50 values ranging from 32.65 ± 2.72 to 212.76 ± 8.30 µM and compound 3 displayed the strongest inhibition of AChE, with IC50 values of 32.65 ± 2.72 µM (in comparison to the reference drug, galanthamine, which had an IC50 of 2.40 ± 0.45 µM).

A new crinane-type alkaloid, 6-epihydroxypowelline (1), together with six known alkaloids, lycorine (2), 2-O-acetyllycorine (3), deacetylbowdensine (4), 1-epideacetylbowdensine (5), 8-demethyl-3-oxomaritidine (6), and (-)-marithamine (7) were isolated from the whole parts of the Crinum latifolium L. in Vietnam. The structure identification of all compounds was determined by 1D, 2D-NMR as well as HR-ESI-MS spectroscopic techniques. The absolute configuration of these compounds was established by the ECD data. In addition, in vitro inhibition of acetylcholinesterase (AChE) activities was assessed for all isolated alkaloids. All alkaloids had AChE inhibitory effects, with IC50 values ranging from 32.65 ± 2.72 to 212.76 ± 8.30 µM and compound 3 displayed the strongest inhibition of AChE, with IC50 values of 32.65 ± 2.72 µM (in comparison to the reference drug, galanthamine, which had an IC50 of 2.40 ± 0.45 µM).

A new crinane-type alkaloid, 6-epihydroxypowelline (1), together with six known alkaloids, lycorine (2), 2-O-acetyllycorine (3), deacetylbowdensine (4), 1-epideacetylbowdensine (5), 8-demethyl-3-oxomaritidine (6), and (-)-marithamine (7) were isolated from the whole parts of the Crinum latifolium L. in Vietnam. The structure identification of all compounds was determined by 1D, 2D-NMR as well as HR-ESI-MS spectroscopic techniques. The absolute configuration of these compounds was established by the ECD data. In addition, in vitro inhibition of acetylcholinesterase (AChE) activities was assessed for all isolated alkaloids. All alkaloids had AChE inhibitory effects, with IC50 values ranging from 32.65 ± 2.72 to 212.76 ± 8.30 µM and compound 3 displayed the strongest inhibition of AChE, with IC50 values of 32.65 ± 2.72 µM (in comparison to the reference drug, galanthamine, which had an IC50 of 2.40 ± 0.45 µM).

Objective: The purpose of this study was to identify factors associated with twin pregnancy following day 3 double embryo transfer (DET). Methods: This retrospective cohort study incorporated data from 16,972 day 3 DET cycles. The participants were women aged between 18 and 45 years who underwent in vitro fertilization with intracytoplasmic sperm injection (IVF/ICSI) at My Duc Assisted Reproduction Technique Unit (IVFMD), My Duc Hospital, located in Ho Chi Minh City, Vietnam. Results: Of the 16,972 day 3 DET cycles investigated, 8,812 (51.9%) resulted in pregnancy. Of these, 6,108 cycles led to clinical pregnancy, with 1,543 (25.3% of clinical pregnancies) being twin pregnancies. Factors associated with twin pregnancy included age under 35 years (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.32 to 1.71; p<0.001) and cycles involving the transfer of at least one grade I embryo. Relative to the transfer of two grade III embryos, the risk of twin pregnancy was significantly elevated following the transfer of two grade I embryos (OR, 1.40; 95% CI, 1.16 to 1.69; p<0.001) or a combination of one grade I and one grade II embryo (OR, 1.27; 95% CI, 1.05 to 1.55; p=0.001). Conclusion By analyzing a large number of IVF/ICSI cycles, we identified several predictors of twin pregnancy. These findings can assist medical professionals in tailoring treatment strategies for couples with infertility.

Objectives: This study was conducted to characterize the symptoms, mental health, quality of life (QoL), and associated factors following the coronavirus disease 2019 (COVID-19) infection. Methods: This cross-sectional study included 394 participants previously infected with COVID-19 in Ho Chi Minh City, Vietnam. Mental health was assessed using the 21-item Depression, Anxiety, and Stress Scale (DASS-21). Participants self-reported health-related QoL was measured with the EuroQol 5-Dimension 5-Level (EQ-5D-5L) scale. Results: Among the participants, 76.4% reported experiencing at least one symptom following COVID-19 infection. The most common symptoms were fatigue (42.1%), cognitive dysfunction (42.9%), and hair loss (27.9%). According to the DASS-21 results, the proportions of depression, anxiety, and stress were 28.7%, 26.4%, and 20.6%, respectively. The mean scores on the EQ-5D-5L and the EuroQol Visual Analog Scale were 0.94±0.11 and 84.20±13.11, respectively. Regarding QoL issues, the highest proportion of participants (32.7%) reported experiencing anxiety or depression, followed by pain or discomfort (25.4%). Multivariable logistic regression analysis revealed that factors associated with the presence of symptoms following COVID-19 infection included female (odds ratio [OR], 2.84; 95% confidence interval [CI], 1.65 to 4.91) and having QoL issues (OR, 3.25; 95% CI, 1.71 to 6.19). Conclusions The study investigated the prevalence rates of various symptoms following COVID-19 infection. These findings underscore the need to prioritize comprehensive care for individuals recovering from COVID-19 and to implement strategies to mitigate the long-term impact of the disease on mental health and QoL.

Objectives: The prevalence of posttraumatic stress disorder (PTSD) has increased, particularly among individuals who have recovered from coronavirus disease 2019 (COVID-19) infection. Health literacy is considered a “social vaccine” that helps people respond effectively to the pandemic. We aimed to investigate the association between long COVID-19 and PTSD, and to examine the modifying role of health literacy in this association. Methods: A cross-sectional study was conducted at 18 hospitals and health centers in Vietnamfrom December 2021 to October 2022. We recruited 4,463 individuals who had recovered from COVID-19 infection for at least 4 weeks. Participants provided information about their sociodemographics, clinical parameters, health-related behaviors, health literacy (usingthe 12-item short-form health literacy scale), long COVID-19 symptoms and PTSD (Impact Event Scale-Revised score of 33 or higher). Logistic regression models were used to examine associations and interactions. Results: Out of the study sample, 55.9% had long COVID-19 symptoms, and 49.6% had PTSD.Individuals with long COVID-19 symptoms had a higher likelihood of PTSD (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.63–2.12; p < 0.001). Higher health literacy was associated with a lower likelihood of PTSD (OR, 0.98; 95% CI, 0.97–0.99; p = 0.001). Compared to those without long COVID-19 symptoms and the lowest health literacy score, those with long COVID-19 symptoms and a 1-point health literacy increment had a 3% lower likelihood of PTSD (OR, 0.97; 95% CI, 0.96–0.99; p = 0.001). Conclusion Health literacy was found to be a protective factor against PTSD and modified the negative impact of long COVID-19 symptoms on PTSD.