Estimating typhoid incidence from community-based serosurveys: a multicohort study.

BACKGROUND: The incidence of enteric fever, an invasive bacterial infection caused by typhoidal Salmonellae (Salmonella enterica serovars Typhi and Paratyphi), is largely unknown in regions without blood culture surveillance. The aim of this study was to evaluate whether new diagnostic serological markers for typhoidal Salmonella can reliably estimate population-level incidence. METHODS: We collected longitudinal blood samples from patients with blood culture-confirmed enteric fever enrolled from surveillance studies in Bangladesh, Nepal, Pakistan, and Ghana between 2016 and 2021 and conducted cross-sectional serosurveys in the catchment areas of each surveillance site. We used ELISAs to measure quantitative IgA and IgG antibody responses to hemolysin E and S Typhi lipopolysaccharide. We used Bayesian hierarchical models to fit two-phase power-function decay models to the longitudinal antibody responses among enteric fever cases and used the joint distributions of the peak antibody titres and decay rate to estimate population-level incidence rates from cross-sectional serosurveys. FINDINGS: The longitudinal antibody kinetics for all antigen-isotypes were similar across countries and did not vary by clinical severity. The seroincidence of typhoidal Salmonella infection among children younger than 5 years ranged between 58·5 per 100 person-years (95% CI 42·1-81·4) in Dhaka, Bangladesh, to 6·6 per 100 person-years (4·3-9·9) in Kavrepalanchok, Nepal, and followed the same rank order as clinical incidence estimates. INTERPRETATION: The approach described here has the potential to expand the geographical scope of typhoidal Salmonella surveillance and generate incidence estimates that are comparable across geographical regions and time. FUNDING: Bill & Melinda Gates Foundation. TRANSLATIONS: For the Nepali, Bengali and Urdu translations of the abstract see Supplementary Materials section.

Nanocomposites of NiO/CuO Based MOF with rGO: An Efficient and Robust Electrocatalyst for Methanol Oxidation Reaction in DMFC.

In this work a novel bimetallic nickel oxide/copper oxide metal-organic framework (NiO/CuO MOF) has been developed by using two linkers: Benzene Dicarboxylic acid (BDC) and Pyrazine. The composites of NiO/CuO MOF with different amounts of reduced graphene oxide (rGO) were synthesized through a hydrothermal method and subsequently characterized by multiple significant techniques like XRD, SEM, EDX, FTIR and Raman IR for an investigation of their structural and morphological properties. The prepared series of material was later employed for electrochemical oxidation of methanol, tested by cyclic voltammetry (CV) in basic medium on a modified glassy carbon electrode (GCE). The electrochemical response depicts that increasing concentration of rGO enhances the electrocatalytic activity of the catalyst for methanol oxidation reaction (MOR). The catalyzed oxidation reaction of methanol by NiO/CuO MOF and rGO-NiO/CuO MOF composites give a superlative current density of 437. 28 mA/cm2 at 0.9 V potential at 50 mV/s scan rate. This activity makes it a promising catalytic material for electrolysis of methanol in direct methanol fuel cell (DMFC).