ABSTRACT
Background: There were widespread unconfirmed reports about the increased severity of dengue post-second wave of the COVID-19 pandemic in India. It is known that a second dengue infection with a different strain in an individual can trigger antibody-dependent enhancement (ADE). A similar phenomenon is hypothesized for severe COVID-19 infection since both dengue and COVID-19 are viral diseases with different and varying strains. However, much research is needed to confirm this hypothesis. In this context, we intended to assess the severity of dengue illness in relation to previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, possibly the role of COVID-19 antibodies as an early predictor of severe dengue illness. Objective: To assess the utility of COVID-19 antibodies for early identification of severe dengue illness among children in the post-third-wave period of COVID-19 infection in India. Materials and methods: All hospitalized children with dengue illness were categorized as severe (shock and/or hemorrhage and/or multi-organ dysfunction) and non-severe dengue illness (dengue with or without warning signs) as per WHO definition. COVID-19 antibody titers were estimated in both groups. Clinical features and seroprevalence of COVID-19 antibodies were compared in both groups. Result: A total of 31 children were studied (13 severe and 18 non-severe dengue illnesses). The most common symptoms prior to presenting to the hospital included fever (100% in both groups), vomiting (85% in severe and 63% in non-severe), abdominal pain (85% in severe and 50% in non-severe), poor feeding (54% in severe and 28% in non-severe), and skin rashes (15% in severe and none in non-severe). The mean duration from the onset of fever to the first hospital visit was 4.6 days in severe illness and 5.3 days in non-severe dengue illness. The mean duration of hospitalization was 9.7 days in severe dengue illness and 4.1 days in non-severe dengue illness. While 92.3% of all severe dengue had significantly higher COVID-19 antibody titers, it was found elevated only in 44.4% of the children with non-severe dengue illness (p-value 0.0059; Yates’ corrected p-value 0.0179). Conclusion: Clinical symptoms prior to presenting to the hospital were fever, vomiting, abdominal pain, poor oral feeding, and skin rashes. While fever, vomiting, and abdominal pain were seen commonly in both severe and non-severe dengue illnesses, the presence of skin rash during febrile phase is associated with severe dengue illness only. Hospitalized children having severe dengue had increased seroprevalence of COVID-19 antibodies (92.3%) compared to children with non-severe dengue (44.4%). However, there is no corelation of the severity of dengue illness with absolute values of COVID-19 antibody levels. Therefore, the presence of COVID-19 antibodies (previous COVID-19 infection) can be a predictor of severe illness in children with dengue especially if associated with poor oral feeding and skin rashes. The limitation of the study is its lesser sample size to conclude any definitive statement; nevertheless, the study paves way for a similar cohort of a larger sample size to draw conclusions.
ABSTRACT
We are reporting a novel approach for preparing silver nanoparticles with seed coat exudates of Celastrus paniculatus Willd, a medicinal plant traditionally used for the treatment of skin diseases, fever, leprosy and neurological disorders. HPTLC study revealed that aqueous, soluble seed coat exudates contain phenolics, alakaloids and flavonoids. The formation, crystalline nature and morphology of the nanoparticles were identified by UV–Vis spectroscopy, X-ray Diffraction (XRD) analysis, Transmission Electron Microscopy (TEM) and selected-area electron diffraction (SAED). Functional group stretching of aqueous soluble extracts was identified by using FTIR. Results revealed that nanosilver particles are spherical, range in size from 10 to 82 nm and crystalize in face-centered cubic structures. Surface-enhanced Raman spectra analysis showed that AgNP are capped with bioactive molecules from exudates and that they may act as precursors of the reduction of silver nitrate from the metallic state (Ag+) to the atomic state (Ag0). We also examined the minimal inhibitory concentration for bacteria Escherichia coli and Bacillus subtilis using a resazurin color assay. Nanosilver strongly inhibited the bacterial growth, leading to MIC values of 40µg/ml and 60µg/ml for the bacteria, respectively. The colony screening method and inhibition kinetics of biofilm formation in the Klebsiella pneumoniae strain were also studied using the tube method and a quantitative microplate assay. SEM analysis and quantification of the EPS revealed a fivefold decrease in concentration in treated compared to untreated. The inhibition response was duly reflected in SEM images.