The evaluation of anti-diphtheria toxoid antibodies in healthy population in Kon Tum, Vietnam: a population-based study.

Background: Despite diphtheria immunization are to apply an effective primary immunization in childhood and to maintain immunity throughout life. Cases of diphtheria have been reported in Viet Nam in recent years. The aim of this study was to evaluate the seroprevalence of IgG antibodies to diphtheria toxoid among healthy person population in Kon Tum, Viet Nam. Methods: Blood samples were obtained from 2225 healthy persons aged 2-98 years collected in 2019 and 2020. Samples were tested for diphtheria toxoid antibodies by commercial Anti-Diphtheria Toxoid IgG Enzyme-Linked Immunosorbent Assay (ELISA). Results: An antibody level of <0.01 IU/mL (susceptibility) was found in 802 (36.0%) of the 2225 subjects, 136 (6.1%) had antibody levels of 0.01-0.099 IU/mL (basic protection), and 1287 (57.8%) had antibody levels ≥0.1 IU/mL (full protection). The full protection level increased significantly in persons aged above 60 years with antibody levels of 70.6%. No significant difference in seroprotection prevalence was found according to gender, ethnicity, residence, education and occupation. The results also demonstrated that people with vaccination against diphtheria during past 10 years were found to have a high immunity (83.8%) compared to 54.8% (OR: 4.7; 95%CI: 3.8-6.5) and 60.7% (OR: 3.8; 95%CI: 2.6-5.7) in persons with no and unknown vaccination (p <0.0001). Conclusions: The level of anti-diphtheria toxoid antibodies among children and adults in Kon Tum was low. The high risk of diphtheria outbreaks may occur among individuals lacking basic immunity against diphtheria.

A flat-lying dimer as a key intermediate in NO reduction on Cu(100).

The reaction of nitric oxide (NO) on Cu(100) is studied by scanning tunneling microscopy, electron energy loss spectroscopy and density functional theory calculations. The NO molecules adsorb mainly as monomers at 64 K, and react and dissociate to yield oxygen atoms on the surface at ∼70 K. The temperature required for the dissociation is significantly low for Cu(100), compared to those for Cu(111) and Cu(110). The minimum energy pathway of the reaction is via (NO)2 formation, which converts into a flat-lying ONNO and then dissociates into N2O and O with a considerably low activation energy. We propose that the formation of (NO)2 and flat-lying ONNO is the key to the exceptionally high reactivity of NO on Cu(100).

How do the doping concentrations of N and B in graphene modify the water adsorption?

Understanding the interaction of water and graphene is crucial for various applications such as water purification, desalination, and electrocatalysis. Experimental and theoretical studies have already investigated water adsorption on N- and B-doped graphene. However, there are no reports available that elucidate the influences of the N and B doping content in graphene on the microscopic geometrical structure and the electronic properties of the adsorbed water. Thus, this work is devoted to solving this problem using self-consistent van der Waals density functional theory calculations. The N and B doping contents of 0.0, 3.1, 6.3, and 9.4% were considered. The results showed that the binding energy of water increases almost linearly as a function of doping content at all concentrations for N-doped graphene but below 6.3% for B-doped graphene. In the linear range, the binding energy increases by approximately 30 meV for each increment of the doping ratio. Analyses of the geometric and electronic structures explained the enhancement of the water-graphene interaction with the variation in doping percentage.

Neurodevelopment at 2 years corrected age among Vietnamese preterm infants.

BACKGROUND: Preterm infants are at risk of neurodevelopmental delay, but data on long-term outcomes in low-income and middle-income countries remain scarce. OBJECTIVES: To examine neurodevelopment using Bayley Scales of Infant and Toddler Development-3rd edition (Bayley-III) and neurological findings in 2-year-old preterm infants, and to compare with healthy Vietnamese infants. Further, to assess factors associated with neurodevelopmental impairment. DESIGN AND SETTING: Cohort study to follow up preterm infants discharged from a neonatal intensive care unit (NICU) of a tertiary children's hospital in Vietnam. PARTICIPANTS: Infants born at <37 weeks of gestational age. MAIN OUTCOMES: Bayley-III assessment and neurological examination at 2-year corrected age (CA) compared with healthy Vietnamese infants. RESULTS: Of 294 NICU preterm infants, Bayley-III scores of all 184/243 (76%) survivors at 2 years CA were significantly lower than those of healthy Vietnamese peers in all three domains: cognition (mean (SD): 84.5 (8.6) vs 91.4 (7.5), p<0.001), language (mean (SD): 88.7 (12.5) vs 95.9 (11.9), p<0.001) and motor (mean (SD): 93.1 (9.0) vs 96.8 (9.3), p=0.003). The mean differences in Bayley-III scores between preterm and healthy Vietnamese infants were -6.9 (-9.1 to -4.7), -7.2 (-10.5 to -3.8) and -3.7 (-6.1 to -1.2) for cognitive, language and motor scores, respectively. The prevalence of neurodevelopmental impairment was 17% for cognitive, 8% for language and 4% for motor performance. In total, 7% were diagnosed with cerebral palsy. Higher maternal education was positively associated with infant neurodevelopment (OR 0.32, 95% CI 0.11 to 0.94). CONCLUSIONS: Vietnamese preterm infants in need of neonatal intensive care showed poor neurodevelopment at 2 years. Higher maternal education was positively associated with infant neurodevelopment. Standard follow-up programmes for preterm infants should be considered in low-resource settings.

Expanding severe acute respiratory infection (SARI) surveillance beyond influenza: The process and data from 1 year of implementation in Vietnam.

BACKGROUND: In 2016, as a component of the Global Health Security Agenda, the Vietnam Ministry of Health expanded its existing influenza sentinel surveillance for severe acute respiratory infections (SARI) to include testing for 7 additional viral respiratory pathogens. This article describes the steps taken to implement expanded SARI surveillance in Vietnam and reports data from 1 year of expanded surveillance. METHODS: The process of expanding the suite of pathogens for routine testing by real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) included laboratory trainings, procurement/distribution of reagents, and strengthening and aligning SARI surveillance epidemiology practices at sentinel sites and regional institutes (RI). RESULTS: Surveillance data showed that of 4003 specimens tested by the RI laboratories, 20.2% (n = 810) were positive for influenza virus. Of the 3193 influenza-negative specimens, 41.8% (n = 1337) were positive for at least 1 non-influenza respiratory virus, of which 16.2% (n = 518), 13.4% (n = 428), and 9.6% (n = 308) tested positive for respiratory syncytial virus, rhinovirus, and adenovirus, respectively. CONCLUSIONS: The Government of Vietnam has demonstrated that expanding respiratory viral surveillance by strengthening and building upon an influenza platform is feasible, efficient, and practical.