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.

Ovarian cancer is a primary global health concern, often diagnosed at advanced stages with limited treatment options and poor prognosis. Natural products have emerged as potential sources of safe and effective therapies. From the seeds of Myristica fragrans Houtt. (nutmeg), 24 compounds, including neolignans and diarylnonanoid derivatives, were isolated and structurally elucidated. The cytotoxic activities of these isolated metabolites against cisplatin-sensitive and resistant human ovarian cancer cell lines were evaluated. In particular, myrifragranone C (23) exhibited cytotoxicity against all test cancer cell lines A2780, TOV-112D, and SK-OV3 with IC50 values of 14.1, 16.9, and 33.4 μM, respectively. Furthermore, compound 23 induced the death of A2780 and SK-OV3 cancer cells via apoptosis. Western blotting revealed that compound 23 significantly increased the expression of cleaved caspase-3 and poly-ADP ribose polymerase and promoted apoptosis via the mitogenactivated protein kinase signaling pathway. Our findings may provide a preliminary understanding of the antiovarian cancer effect of the active compound myrifragranone C as a potential treatment using natural products.

The optimal condition for Moringa oleifera root barks extraction was determined using response surface methodology and Box-Behnken Design. The actual optimal condition of the factors was 65 o C, ethanol 60%, 40 (mL/g) liquid-to-solid ratio with 240 minutes extraction time. The enrichment of phenolic compounds sharply affected the antioxidant, and inhibitions of α-amylase enzyme, as well as, the anti-inflammatory effect of the extract from M. oleifera root barks. The extract in the optimal condition exhibited better 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and α-amylase inhibitory activities than those of positive controls.Also, the extract showed weak hydroxyl free radical scavenging and nitric oxide (NO) production inhibitory effects. These revealed a simple and promising method for the preparation of bioactive products from the root bark of M. oleifera.

Objective: To investigate the cause of a botulism outbreak in several provinces in Viet Nam in 2020. Methods: An initial investigation was conducted to confirm the outbreak and to form hypotheses about the potential causes, followed by a case–control assessment of the plausible causative food item. Collected food samples were tested to identify the pathogen, and mouse bioassays were performed. Control measures were introduced to stop the outbreak and to prevent similar events in the future. Results: Twelve people in six southern provinces of Viet Nam were identified as having symptoms of botulism, of whom 11 were in critical condition requiring breathing support. A history of foods eaten in the 4 days before illness onset indicated that all the cases had eaten a tinned vegetarian pate, and a case–control assessment showed that this was significantly associated with the outbreak, with an odds ratio of 35.2 (95% confidence interval: 3.4–infinity). Clostridium botulinum type B was detected in three of eight pâté samples collected from the houses of cases. In the mouse bioassay for the toxicity of the pâté samples, all the mice died with clinical symptoms of botulism. Discussion: A tinned vegetarian pate was the plausible cause of a botulism outbreak in Viet Nam in 2020. Revision of food safety regulations to improve quality control of tinned foods to prevent future outbreaks is recommended.

Objective: Female sex workers (FSWs) are at high risk of human papillomavirus (HPV) infections and cervical cancer due to their high number of sexual partners. The objectives of this study were to determine the prevalence of HPV and identify risk factors for high-risk HPV infection among FSWs in Hanoi and Ho Chi Minh City (HCMC), Viet Nam. Methods: A cross-sectional study was conducted in Hanoi and HCMC between December 2017 and May 2018. We surveyed and screened 699 FSWs aged ≥18 years for HPV infection and abnormal cytology. A multivariable modified Cox regression model was used to determine risk factors for high-risk HPV infection. Results The overall prevalence of any HPV, high-risk HPV and HPV-16/18 infection in the 699 FSWs was 26.3%, 17.6% and 4.0%, respectively, and were similar in both cities. Multiple infections were identified in 127 participants (69.0%).HPV-52 was the most prevalent (7%), followed by HPV-58 (6%). Abnormal cytology was detected in 91 participants (13.0%). FSWs who are divorced (adjusted prevalence ratio [aPR]: 1.96, 95% confidence interval [CI]: 1.01–3.81), widowed (aPR: 3.26, 95% CI: 1.49–7.12) or living alone (aPR: 1.85, 95% CI: 1.01–3.39) were associated with a higher prevalence of high-risk HPV infection.

Endophytic fungi are promising sources for the production of podophyllotoxin-an important anticancer compound, replacing depleted medical plants. In this study, the endophytes associated with Dysosma difformis-an ethnomedicinal plant species were isolated to explore novel sources of podophyllotoxin. Fifty-three endophytic fungi were isolated and identified by morphological observation and ITS-based rDNA sequencing, assigning them to 27 genera in 3 divisions. Fusarium was found the most prevalent genus with a colonization frequency of 11.11%, followed by Trametes (9.26%) and Penicillium (7.41%). Phylogenetic trees were constructed for the endophytic fungi community in two collection sites, Ha Giang and Lai Chau, revealing the adaptation of the species to the specific tissues and habitats. Cytotoxic activity of endophytic fungal extracts was investigated on cancer cell lines such as SK-LU-1, HL-60, and HepG2, demonstrating strong anti-cancer activity of six isolates belonging to Penicillium, Trametes, Purpureocillium, Aspergillus, and Ganoderma with IC 50 value of lower than 10 10 µg/mL. The presence of podophyllotoxin was indicated in Penicillium, Trametes, Aspergillus and for the first time in Purpureocillium and Ganoderma via high-performance liquid chromatography, which implied them as a potential source of this anticancer compound.

Objectives: Asymptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and test re-positivity after a negative test have raised concerns about the ability to effectively control the coronavirus disease 2019 (COVID-19) pandemic. We aimed to investigate the prevalence of COVID-19 asymptomatic and pre-symptomatic infections during the second wave of COVID-19 in Viet Nam, and to better understand the duration of SARS-CoV-2 infection and the dynamics between the evolution of clinical symptoms and SARS-CoV-2 test positivity among confirmed COVID-19 cases. Methods: We conducted a cohort analysis on the first 50 confirmed cases during the second COVID-19 wave in Viet Nam using clinical, laboratory and epidemiological data collected from 9 March to 30 April 2020. Kaplan-Meier estimates were used to assess time to clearance of SARS-CoV-2 infection, and log-rank tests were used to explore factors related to time to SARS-CoV-2 infection clearance. Results: Most cases (58%) had no typical signs or symptoms of COVID-19 at the time of diagnosis. Ten cases (20%) were re-positive for SARS-CoV-2 during infection. Eight cases (16%) experienced COVID-19 symptoms after testing negative for SARS-CoV-2. The median duration from symptom onset until clearance of infection was 14 days (range: 6–31); it was longer in re-positive and older patients and those with pre-existing conditions. Conclusion Asymptomatic and pre-symptomatic infections were common during the second wave of COVID-19 in Viet Nam. Re-positivity was frequent during hospitalization and led to a long duration of SARS-CoV-2 infection.

Animals ; Antibodies, Neutralizing ; Blotting, Western ; Classical swine fever virus ; Classical Swine Fever ; Enzyme-Linked Immunosorbent Assay ; Genotype ; Mortality ; Spleen ; Swine ; Vaccines ; Vaccines, Subunit ; Vietnam ; Virulence

Background: The evidence for the efficacy and safety of balloon kyphoplasty (BKP) in treating the Vietnamese patients is sparse. There is no convincing evidence regarding BKP’s efficacy in Vietnamese patients, especially in the patients with thoracic osteoporotic vertebral compression fractures (VCFs). This article aims to evaluate the outcomes of restoring the body height of the compressed thoracic vertebrae in patients undergoing BKP. Methods: We prospectively enrolled 65 consecutive patients with thoracic VCFs (73 vertebrae) due to osteoporosis who were treated with BKP between June 2018 and May 2019. Results: A trocar was inserted through the pedicle in 84.9% (62/73) and beside the pedicle in 15.1% (11/73). The mean amount of mixed cement injected was 4.1 ± 1.1 mL (range, 1.5–7 mL). Cement leakage was radiographically confirmed in 30.8% of 65 patients. Among patients with complications caused by cement extravasation, the leakage was through the anterior margin of the vertebrae in 15.4%, through the vertebral disc in 12.3%, and through the posterior margin of the vertebrae in 3.1%. In the last 3.1% of patients, there was no clinically notable lesions of the nerve roots or spinal cord. The mean visual analog scale score decreased significantly from 7.3 ± 1.1 preoperatively to 3.3 ± 0.6 at 24 hours after surgery, and then to 1.2 ± 1.1 at 3 months after surgery (p < 0.01). The mean reduction in Cobb angle measured on standing radiographs after treatment was 3.7°, showing statistical significance (p < 0.01). Conclusions BKP is a minimally invasive treatment effective for immediate pain relief, early motor rehabilitation, and humpback correction. The present study provided convincing evidence to support the use of BKP by spine surgeons and clinical specialists in treating osteoporotic thoracic VCFs in Vietnamese patients.

Objective: To evaluate the anti-arthritic effects of Polygonatum kingianum rhizome extract using both in vitro and in vivo models.Methods: Lipopolysaccharide-induced RAW 264.7 macrophages were treated with an ethanol extract of Polygonatum kingianum rhizomes at different concentrations to determine nitric oxide and prostaglandin E2 (PGE2) production. For in vivo study, Polygonatum kingianum ethanol extract was further investigated for its anti-inflammatory effect in a mouse model with collagen antibody-induced arthritis. Phytochemical study of Polygonatum kingianum ethanol extract was also performed. Results: Saponins (142 mg/g total yield) was the main component in the Polygonatum kingianum ethanol extract. 5α,8α-ergosterol peroxide, (E,E)-9-oxooctadeca-10,12-dienoic acid and 3-(2?-hydroxy-4?-methoxy-benzyl)-5,7-dihydroxy-8-methyl-chroman-4-one were isolated from the extract. Polygonatum kingianum ethanol extract exhibited potential anti-inflammatory effects by inhibiting nitric oxide and PGE2 production in RAW 264.7 cells in a dose-dependent manner. The level of arthritis in mice with collagen antibody-induced arthritis was significantly reduced (P<0.01) after treatment with Polygonatum kingianum ethanol extract, particularly at a dose of 1?000 mg/kg body weight. Besides, the extract demonstrated the regulatory effects on serum tumor necrosis factor-alpha, interleukin-6, and interleukin-10 in treated mice. Conclusions: Polygonatum kingianum ethanol extract has beneficial effects on inflammatory cytokine regulation and PGE2 inhibition in an experimental mouse model with collagen antibody-induced arthritis. The phytochemical screening reveals that the saponin, as the main component, and sterols (daucosterol and 5α,8α-ergosterol peroxide) from Polygonatum kingianum ethanol extract may contribute to its promising in vitro and in vivo anti-inflammatory activities.