Clinical Manifestations and Complications of Children With COVID-19 Compared to Other Respiratory Viral Infections: A Cohort Inpatient Study From Rio de Janeiro, Brazil

IntroductionThe coronavirus disease-2019 (COVID-19) clinical manifestations in children and adolescents are diverse, despite the respiratory condition being the main presentation. Factors such as comorbidities and other respiratory infections may play a role in the initial presentation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aims to describe the epidemiological aspects, clinical, and laboratory manifestations of pediatric patients admitted to a tertiary pediatric hospital in Rio de Janeiro, diagnosed with COVID-19, and compare these with other viral conditions during the first year of the SARS-CoV-2 pandemic.MethodsAll patients under 18 years of age that were admitted with upper airway infection were enrolled and followed up for 30 days. The main dependent variable was the laboratorial diagnosis of SARS-CoV-2, and independent variables were studied through logistic regression.ResultsA total of 533 patients were recruited, and 105 had confirmed SARS-CoV-2 infection. Detection of other viruses occurred in 34% of 264 tested participants. Six patients died (two in SARS-CoV-2 infected group). The variables independently associated with COVID-19 were older age (OR = 1.1, 95% CI = 1.0–1.1), lower leukocytes count at entry (OR = 0.9, 95% CI = 0.8–0.9), and contact with suspected case (OR = 1.6, 95% CI = 1.0–2.6). Patients with COVID-19 presented higher odds to be admitted in an intensive care unit (OR = 1.99, 95% CI = 1.08–3.66).ConclusionsEven during the SARS-CoV-2 pandemic, several other respiratory viruses were present in admitted pediatric patients. Variables associated with COVID-19 infection were older age, lower leukocytes count at entry, and a domiciliary suspect contact. Although patients with COVID-19 were more frequently admitted to ICU, we did not observe higher mortality in this group

A SARS-CoV-2 Negative Antigen Rapid Diagnostic in RT-qPCR Positive Samples Correlates With a Low Likelihood of Infectious Viruses in the Nasopharynx

Severe acute respiratory syndrome-related coronavirus (SARS-CoV-2) transmission occurs even among fully vaccinated individuals; thus, prompt identification of infected patients is central to control viral circulation. Antigen rapid diagnostic tests (Ag-RDTs) are highly specific, but sensitivity is variable. Discordant RT-qPCR vs. Ag-RDT results are reported, raising the question of whether negative Ag-RDT in positive RT-qPCR samples could imply the absence of infectious viruses. To study the relationship between negative Ag-RDT results with virological, molecular, and serological parameters, we selected a cross-sectional and a follow-up dataset and analyzed virus culture, subgenomic RNA quantification, and sequencing to determine infectious viruses and mutations. We demonstrated that RT-qPCR positive while SARS-CoV-2 Ag-RDT negative discordant results correlate with the absence of infectious virus in nasopharyngeal samples. A decrease in sgRNA detection together with an expected increase in detectable anti-S and anti-N IgGs was also verified in these samples. The data clearly demonstrate that a negative Ag-RDT sample is less likely to harbor infectious SARS-CoV-2 and, consequently, has a lower transmissible potential

CARACTERÍSTICAS CLÍNICO-EPIDEMIOLÓGICAS DE PACIENTES COM COVID-19 ATENDIDOS NO NEEDIER/UFRJ EM DIFERENTES ONDAS DE VARIANTES VIRAIS

Introdução/Objetivo: O NEEDIER (Núcleo de Enfrentamento e Estudos de Doenças Infecciosas Emergentes e Reemergentes) foi importante para o diagnóstico da covid-19 na comunidade da UFRJ e profissionais de saúde e segurança pública. Ao longo da pandemia, notaram-se mudanças nas características e sintomas do público atendido, associados às ondas causadas por diferentes variantes do vírus. O presente estudo tem como objetivo avaliar as características clínicas e epidemiológicas da população com diagnóstico de covid-19 atendida no NEEDIER nesses diversos períodos. Métodos: Coorte de indivíduos diagnosticados com covid-19 no NEEDIER. Os indivíduos foram triados e testados por meio de RT-PCR em swab de nasofaringe. Características clínico-epidemiológicas foram coletadas a partir de questionário. Os pacientes assinaram TCLE para participação no projeto (CAAE: 30161620.0.1001.5257). Ondas de variantes foram definidas com os dados estaduais de sequenciamento disponíveis no GISAID. Resultados: Entre 16/mar/2020 e 31/dez/2022, 7931 indivíduos foram diagnosticados com covid-19. No período, quatro variantes virais causaram ondas delimitadas da doença: original (3756 casos), Gama (752), Delta (412) e Omicron (2554). Houve predominância de mulheres em todos os períodos (59, 48, 58 e 61%, respectivamente, p = 0,46). A idade mediana foi de 38, 37, 35 e 32 anos (p 98%). Os sintomas apresentados mudaram ao longo das diferentes ondas, destacando a importância da atualização de critérios de triagem para um diagnóstico precoce

Development and assessment of a multiepitope synthetic antigen for the diagnosis of Dengue virus infection

Immunodiagnostic tests for detecting dengue virus infections encounter challenges related to cross-reactivity with other related flaviviruses. Our research focuses on the development of a synthetic multiepitope antigen tailored for dengue immunodiagnostics. Selected dengue epitopes involved structural linearity and dissimilarity from the proteomes of Zika and Yellow fever viruses which served for computationally modeling the three-dimensional protein structure, resulting in the design of two proteins: rDME-C and rDME-BR. Both proteins consist of seven epitopes, separated by the GPGPG linker, and a carboxy-terminal 6 × -histidine tag. The molecular weights of the final proteins rDME-C and rDME-BR are 16.83 kDa and 16.80 kDa, respectively, both with an isoelectric point of 6.35. The distinguishing factor between the two proteins lies in the origin of their epitope sequences, where rDME-C is based on the reference dengue proteome, while rDME-BR utilizes sequences from prevalent Dengue genotypes in Brazil from 2008 to 2019. PyMol analysis revealed exposure of epitopes in the secondary structure. Successful expression of the antigens was achieved in soluble form and fluorescence experiments indicated a disordered structure. In subsequent testing, rDME-BR and rDME-C antigens were assessed using an indirect Elisa protocol against Dengue infected serum, previously examined with a commercial diagnostic test. Optimal concentrations for antigens were determined at 10 µg/mL for rDME-BR and 30 µg/mL for rDME-C, with serum dilutions ranging from 1:50 to 1:100. Both antigens effectively detected IgM and IgG antibodies in Dengue fever patients, with rDME-BR exhibiting higher sensitivity. Our in-house test showed a sensitivity of 77.3 % and 82.6 % and a specificity of 89.4 % and 71.4 % for rDME-C and rDEM-BR antigens. No cross-reactivity was observed with serum from Zika-infected mice but with COVID-19 serum samples. Our findings underscore the utility of synthetic biology in crafting Dengue-specific multiepitope proteins and hold promise for precise clinical diagnosis and monitoring responses to emerging Dengue vaccines