Viral and bacterial microorganisms in Vietnamese children with severe and non-severe pneumonia.

To investigate potential respiratory pathogens in children with community-acquired pneumonia (CAP) and risk factors for severe disease. This prospective study was conducted among 467 children at the Thai Binh Paediatric Hospital, Vietnam between 1 July 2020 and 30 June 2021. Clinical data and laboratory results were collected. Twenty-four respiratory microorganisms were tested from nasopharyngeal swabs using real-time PCR. Logistical regression was used to estimate a factor's adjusted odd ratios of the severity of disease. Mean age of patients = 15.4 ± 13.3 months, 63.0% were male. Over 97% of patients had a positive PCR result. 87% of patients were positive for multiple (up to eight) microorganisms. Rhinovirus (46%), respiratory syncytial virus (RSV) (24%), enterovirus (17%), and parainfluenza viruses-3 (13%) were the most frequent viruses. H. influenzae (61%), S. pneumoniae (45%) and M. catarrhalis (30%) were the most common bacteria. 128 (27%) cases were classified as severe pneumonia. Presence of smokers at home (aOR 2.11, 95% CI 1.27-3.52, P value = 0.004), CRP level ≥ 50 mg/dL (aOR 6.11, 95% CI 3.86-9.68, P value < 0.0001), RSV (aOR 1.78, 95% CI 1.07-2.96, P value = 0.03) and H. influenzae (aOR 1.66, 95% CI 1.03-2.67, P value = 0.04) PCR detection associated with a higher risk of severe pneumonia; ,. Causative agents of pneumonia in children are complex. Children positive with RSV and H. influenzae need to be closely monitored to prevent severe pneumonia.

Short-Term Adverse Effects Immediately after the Start of COVID-19 Booster Vaccination in Vietnam.

Background: Risk communication is necessary to improve the booster vaccination rate, but Vietnam does not have a system to collect and disclose such information. Therefore, the purpose of this study was to clarify adverse reactions and their frequency in the early period after booster vaccination, and to obtain primary data for improving the booster vaccination rate. Methods: A cross-sectional survey was conducted among adults aged ≥18 years. Clinical data were collected 14 days after booster vaccination by using a standard questionnaire. Results: A total of 1322 participants were included with median age = 23 and sex ratio (Male/Female) = 0.53. AstraZeneca was the most commonly used vaccine for the first and second doses, while Pfizer was the most commonly used vaccine for booster shots. Injection site pain, fatigue, and myalgia were the most common side effect reported (71.9%, 28.1%, and 21.8%, respectively). Compared to previous COVID-19 vaccine injections, 81.9% of participants reported that their symptoms were similar or milder after receiving the booster dose. They were more likely to present injection site pain (OR = 1.43, p < 0.0001) and lymphadenopathy (OR = 4.76, p < 0.0001) after receiving the booster shot. Fever (OR = 0.33, p < 0.0001) and fatigue (OR = 0.77, p = 0.002) were less often reported after booster shots compared to the first and second injections. The severity of symptoms occurring after booster dose versus first and second doses increased significantly with each additional year of age and among participants receiving the Pfizer and Moderna vaccines. Conclusion: Adverse reactions to booster vaccination are minor and their incidence is the same as for the first or the second vaccination. Multicenter studies with larger sample sizes on the side effects and safety of COVID-19 vaccine booster shots need to be conducted to make the population less worried, in order to increase the vaccination rate, to protect individuals' and communities' health.

Outbreak of central nervous system infections among children in Thai Binh, Viet Nam.

From July to October 2020, 99 cases of central nervous system (CNS) infections were identified in Thai Binh Pediatric Hospital, Viet Nam, representing a five-fold increase compared to the baseline incidence during the previous five years. Clinical data were retrospectively collected. Cerebrospinal fluid specimens (CSF) were secondarily tested for pathogens using viral culture and PCR assays. Patient median age was 5 years (0-12 years); 58.6% were male. Of these children, 83.8% had CSF white blood culture (WBC) counts of ≥ 10 cells/µL, including 58 of 99 (58.6%) with a WBC count ≥ 100 cells/µL. Overall, 72 (72.7%) patients had confirmed infections with a pathogen identified in the CSF, the majority of which (66) were enterovirus. Sequencing results suggested that the rise of incidence observed in 2020 was due to Echovirus 4 (n = 45), Echovirus 30 (n = 8), and Echovirus 6 (n = 1) circulation. A confirmed CNS infection was significantly associated with older age (≥5 years, OR = 3.64, p = 0.03) and with an increased WBC count in the CSF (OR = 6.38, p-value = 0.01 for WBCs from 10 to <100 and OR = 7.90, p-value = 0.002 for WBCs ≥100). Ninety-seven (97) of 99 (98.0%) children received empiric antimicrobial treatment, and 35 (35.3%) were treated with multiple antibiotics. Eighty-four (84) patients (84.9%) were discharged home, and 11 (11.1%) were transferred to the National Hospital because their condition had worsened. No deaths were recorded. Point-of-care tests, including real-time PCR assays to identify common pathogens, should be implemented for more accurate diagnosis and more appropriate antibiotic use.

Effect of the COVID-19 Outbreak on the Incidence of Other Respiratory and Gastrointestinal Infections in Children in Thai Binh, Vietnam in 2020.

INTRODUCTION: To evaluate the impact of COVID-19 mitigation measures on the total number of consultations for respiratory and gastrointestinal infections among children under 16 years in Thai Binh Pediatric Hospital, Vietnam during the year 2020. METHODS: A retrospective study was carried out to review consecutive consultations occurring in children admitted from January 01, 2016 to December 31, 2020. All medical records were collected from the central numeric database of the hospital. Diagnoses were documented according to the International Classification of Diseases 10 criteria. RESULTS: 436,276 children consulted at the outpatient department during the period of study. A gradual increase in the total number of outpatients was observed from 2016 to 2019, including those consulting for respiratory and gastrointestinal infections. However, the total number of outpatients and the numbers of those consulting for respiratory and gastrointestinal infections dramatically decreased in 2020. A significant decrease of respiratory infections relative proportion was observed in 2020 when compared to 2016-2019 (p < 0.0001). By contrast, the relative proportion of gastrointestinal infections did not significantly vary (p = 0.91). The proportion of outpatients aged under 5 years was significantly lower in 2020 compared to previous years (p < 0.0001). The proportion of male patients was significantly higher in 2020 than from 2016 to 2019 (p = 0.001). CONCLUSION: Public health measures against the COVID-19 pandemic likely decreased the prevalence of other respiratory tract infections. Further studies are needed to validate the effectiveness of each type of measure. Microbiological studies are also recommended, to better understand the effect of preventive measures.

Seroprevalence of SARS-CoV-2 among high-density communities and hyper-endemicity of COVID-19 in Vietnam.

OBJECTIVE: To assess the magnitude of active and recovering COVID-19 patients among at-risk communities and to identify the factors associated with positive serology. METHODS: Four hundred and eighty-three close contacts of COVID-19 patients residing in Ho Chi Minh City, Vietnam, during the fourth wave of the COVID-19 epidemic (September and October 2021) were included. Five weeks after exposure to a COVID-19 patient, they underwent a serology test using the BIOSYNEX COVID-19 BSS kit. RESULTS: The median age of participants was 37 years. A total of 34.6% individuals presented at least one clinical symptom between the time of contact with the COVID-19 patient and inclusion in study. A total of 1.7% unvaccinated individuals tested positive for SARS-CoV-2 using real-time PCR, and 9.5% had evidence of recent infection (positive PCR and/or IgM). A further 26.7% unvaccinated individuals presented evidence of a past infection (positive IgG only). Socio-demographic characteristics, vaccination status and clinical symptoms were not associated with a positive IgM test. CONCLUSION: This is the first serosurvey conducted during the fourth wave of the epidemic in Vietnam. It revealed a seropositivity rate higher than in previous studies and confirmed the hyperendemicity of SARS-CoV-2. Testing using rapid serological tests proved to be a reliable, easy-to-use method and enabled a rapid estimation of the burden of COVID-19.

Morbidity and Mortality Patterns in Children Admitted to Hospital in Thai Binh, Vietnam: A Five-year Descriptive Study with a Focus on Infectious Diseases.

The objective of this study was to describe the overall pattern of morbidity and mortality of children seen at the Thai Binh Paediatric Hospital in Vietnam, with a focus on infectious diseases. A retrospective review of hospitalisation records was conducted from 1 January 2015 to 31 December 2019. Data were obtained from a total of 113,999 records. The median age of patients was 18 months, with 84.0% of patients aged <5 years. Infectious diseases accounted for 61.0% of all cases. The most prevalent diseases were lower respiratory tract infections (32.8%), followed by gastrointestinal infections (13.3%) and confirmed influenza (5.4%). Most infections were not microbiologically documented. A total of 81.4% patients received at least one antibiotic. Most patients (97.0%) were hospitalised for less than 15 days. Regarding outcomes, 87.8% patients were discharged home with a favourable outcome. Twelve percent were transferred to the Vietnam National Children's Hospital because their condition had worsened and 0.1% died. In total, infectious diseases accounted for 40.4% of deaths, followed by neonatal disorders (34.6%). Our data serves a basis for the identification of needs for diagnostic tools and for future evaluation of the effect of the targeted implementation of such facilities. Point-of-care tests, including real-time polymerase chain reaction assays to identify common pathogens should be implemented for more accurate diagnosis and more appropriate antibiotic use.

Two-dimensional NaxSiS as a promising anode material for rechargeable sodium-based batteries: ab initio material design.

The rapidly rising demand for energy storage systems presents an imperative need to develop sodium-ion batteries with high energy density, high conductivity, and low barrier energy. In this work, we present a Density Functional study on the properties of two-dimensional NaxSiS as a promising anode material for rechargeable sodium-ion batteries. Energetically stable structures of Na-adsorbed silicene sulfide NaxSiS with various Na contents were explored. It is found that the adsorption energy of a Na atom is higher than -0.4 eV and it decreases with increasing Na content. The electronic structure of pristine silicene sulfide shows semiconductor behaviour with a bandgap of 0.99 eV, while the Na-adsorbed SiS exhibits metallic characteristics. The highest theoretical capacity of 187.2 mA h g-1, which is higher than that of well-known two dimensional materials, is found in the fully intercalated phase of SiS Na0.5SiS which corresponds to per side layer. Furthermore, Na ions can diffuse along two typical pathways on the surface of SiS with a small barrier of 183 meV which is much smaller than that of the two dimensional LixSiS, NaxTiS2, and NaxMoS2. All these characteristics suggest that silicene sulfide SiS can be expected to be a promising anode material for sodium ion batteries.

Diffusion mechanism of Na ion-polaron complex in potential cathode materials NaVOPO4 and VOPO4 for rechargeable sodium-ion batteries.

Using the density functional method, we investigated the crystal and electronic structures and the electrochemical properties of NaxVOPO4 (x = 0, 1) and explored the diffusion mechanism of Na ions in these materials. The van der Waals interaction was also taken into account to include the non-local electron correlation in the calculation of structural parameters and voltage. The diffusion of Na ions is treated as a process of the Na vacancy-positive small polaron complex in NaVOPO4 and the Na ion-negative small polaron complex in VOPO4, respectively. During the charging (discharging) process, the removal (insertion) of a Na ion would result in the formation of a positive (negative) small polaron at one of the two first nearest vanadium sites to the Na vacancy. Three elementary diffusion processes, including the single, crossing and parallel diffusion processes, are explored. It is found that the [010] direction is preferable for Na ion diffusion in both the charging and discharging processes. The influence of small polaron migration on Na ion diffusion in the charging state is negligible, whereas such effect is considerably strong in the discharging process. Moreover, while three elementary diffusion processes in NaVOPO4 require the same energy, the parallel diffusion process in VOPO4 is not preferred. The diffusion of Na vacancy accompanied by a positive polaron in the full charging process requires an activation energy of 395 meV, while the diffusion of Na ion accompanied by a negative polaron in the discharging state, VOPO4, has a higher activation energy of 627 meV. With a voltage and activation barrier similar to that of the olivine phosphate LiFePO4, these sodium-based materials are expected to be promising cathode materials for sodium ion batteries.