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Background: The COVID-19 pandemic has significantly impacted education systems worldwide, with Brazil being one of the countries with the longest school closures. Over a million children and teenagers have been affected, leading to increased hunger and nutritional deficiencies. This study aimed to implement long-term surveillance of SARS-CoV-2 infections in public and private schools in Campo Grande, Brazil, after returning to in-person classes., Methods: The study involved testing and genomic surveillance at 23 public and private schools in Campo Grande, Mato Grosso do Sul, Brazil, from October 18, 2021 to November 21, 2022. The participants eligible for enrollment were students aged 6-17 years and staff members from school institutions. At the time of collection, participants were asked if they had symptoms in the last two weeks. Whole-genome sequencing of SARS-CoV-2 was conducted to identify circulating variants and to compare them with those detected in the municipality. The demographic data and clinical history of the participants were described, and a logistic regression model was used to understand how the RT-qPCR results could be related to different characteristics., Results: The study included 999 participants, most of whom were women. A total of 85 tests were positive, with an overall positivity rate of 3.2%. The dynamics of case frequency were consistent with those observed in the municipality during the study period. The most common symptoms reported were cough, rhinorrhea, headache, and sore throat. Symptoms were significantly associated with SARS-CoV-2 infection. Eleven lineages were identified in school community samples, with a frequency of occurrence per period similar to that found in the sequences available for the municipality. The most prevalent lineages within the sampling period were BA.2 (59.3%) and BA.5 (29.6%)., Conclusions: Our findings demonstrate that schools can play a crucial role in epidemiological surveillance, helping trigger rapid responses to pathogens such as SARS-CoV-2. Long-term surveillance can be used to track outbreaks and assess the role of children and adults in transmission. It can also contribute to pandemic preparedness, enabling a rapid response to emergencies, such as COVID-19., (© 2024. The Author(s).)

Introduction: With the reopening of schools during the coronavirus disease 2019 (COVID-19) pandemic, it was imperative to understand the role of students and education professionals in the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this paper, we determined the seroprevalence of the SARS-CoV-2 anti-nucleocapsid antibodies in the school community in Campo Grande, the capital and most populous city of the state of Mato Grosso do Sul (Brazil) and evaluated its association with sex, school level, and school type., Materials and Methods: The survey was carried out in 20 public and private schools in the urban region of Campo Grande using the TR DPP ® COVID-19 immunoglobulin M/immunoglobulin G (IgM/IgG) kit from the Immunobiological Technology Institute (Bio-Manguinhos, Rio de Janeiro, Brazil). Testing was carried out in three periods: from October to December 2021; from March to July 2022; and from August to November 2022. The participants were students aged 6-17 years enrolled in primary or secondary schools and professionals of different ages and roles., Results: During the first testing period, 162 participants were seropositive for the IgM and/or IgG anti-nucleocapsid SARS-CoV-2 antibodies, with an estimated seroprevalence of 19.6% using Bayesian multilevel regression. In the second period, 251 participants were seropositive (estimated seroprevalence, 34.6%), while in the third period, 393 participants were seroconverted (estimated seroprevalence, 56.7%). In 2022, there was an increase in the seroconversion rate compared to that in 2021. The most frequently described acute manifestations in the three periods were fever, headache, sore throat, and runny nose. In terms of the demographic profile, there was no predominance of seropositivity between the sexes, although women represented approximately 70% of the study population. There were also no differences between students and school staff., Discussion: The results made it possible to evaluate the extent of SARS-CoV-2 transmission in the school community through immunity developed against the virus, in addition to providing information about COVID-19 symptoms in children, adolescents, and adults., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Stutz, Alcantara, Santos, Torres, Rodrigues, Marcon, Ferreira, Sarti, Oliveira, Mendes, Lemos, Demarchi, Lichs, Zardin, Gonçalves, Guilhermino, Perdomo and Fernandez.)

Background: The COVID-19 pandemic had a major impact on indigenous populations. Understanding the viral dynamics within this population is essential to create targeted protection measures., Methods: A total of 204 SARS-CoV-2 positive samples collected between May 2020 and November 2021 from an indigenous area in Mato Grosso do Sul (MS), Midwestern Brazil, were screened. Samples were submitted to whole genome sequencing using the Nanopore sequencing platform. Clinical, demographic, and phylogenetic data were analyzed., Results: We found the co-circulation of six main SARS-CoV-2 lineages in the indigenous population, with the Zeta lineage being the most prevalent (27.66%), followed by B.1.1 (an ancestral strain) (20.21%), Gamma (14.36%) and Delta (13.83%). Other lineages represent 45.74% of the total. Our phylogenetic reconstruction indicates that multiple introduction events of different SARS-CoV-2 lineages occurred in the indigenous villages in MS. The estimated indigenous population mortality rate was 1.47%. Regarding the ethnicity of our cohort, 64.82% belong to the Guarani ethnicity, while 33.16% belong to the Terena ethnicity, with a slightly higher prevalence of males (53.43%) among females. Other ethnicities represent 2.01%. We also observed that almost all patients (89.55%) presented signs and symptoms related to COVID-19, being the most prevalent cough, fever, sore throat, and headache., Discussion: Our results revealed that multiple independent SARS-CoV-2 introduction events had occurred through time, probably due to indigenous mobility, since the villages studied here are close to urban areas in MS. The mortality rate was slightly below of the estimation for the state in the period studied, which we believe could be related to the small number of samples evaluated, the underreporting of cases and deaths among this population, and the inconsistency of secondary data available for this study., Conclusion: In this study, we showed the circulation of multiple SARS-CoV-2 variants in this population, which should be isolated and protected as they belong to the most fragile group due to their socioeconomic and cultural disparities. We reinforce the need for constant genomic surveillance to monitor and prevent the spread of new emerging viruses and to better understand the viral dynamics in these populations, making it possible to direct specific actions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 de Oliveira, de Rezende, Navarini, Marchioro, Torres, Croda, Croda, Gonçalves, Xavier, de Castro, Lima, Iani, Adelino, Iani, Aburjaile, Ferraz Demarchi, Taira, Zardin, Fonseca, Giovanetti, Andrews, Alcantara and Simionatto.)

Serological tests developed for COVID-19 diagnostic are based on antibodies specific for SARS-CoV-2 antigens. Most of the antigens consist of a fragment or a whole amino acid sequence of the nucleocapsid or spike proteins. We evaluated a chimeric recombinant protein as an antigen in an ELISA test, using the most conserved and hydrophilic portions of the S1-subunit of the S and Nucleocapsid (N) proteins. These proteins, individually, indicated a suitable sensitivity of 93.6 and 100% and a specificity of 94.5 and 91.3%, respectively. However, our study with the chimera containing S1 and N proteins of SARS-CoV-2 suggested that the recombinant protein could better balance both the sensitivity (95.7%) and the specificity (95.5%) of the serological assay when comparing with the ELISA test using the antigens N and S1, individually. Accordingly, the chimera showed a high area under the ROC curve of 0.98 (CI 95% 0.958-1). Thus, our chimeric approach could be used to assess the natural exposure against SARS-CoV-2 virus over time, however, other tests will be necessary to better understand the behaviour of the chimera in samples from people with different vaccination doses and/or infected with different variants of the virus., (Copyright © 2023. Published by Elsevier B.V.)

Immunity with SARS-CoV-2 infection during the acute phase is not sufficiently well understood to differentiate mild from severe cases and identify prognostic markers. We evaluated the immune response profile using a total of 71 biomarkers in sera from patients with SARS-CoV-2 infection, confirmed by RT-PCR and controls. We correlated biological marker levels with negative control (C) asymptomatic (A), nonhospitalized (mild cases-M), and hospitalized (severe cases-S) groups. Among angiogenesis markers, we identified biomarkers that were more frequently elevated in severe cases when compared to the other groups (C, A, and M). Among cardiovascular diseases, there were biomarkers with differences between the groups, with D-dimer, GDF-15, and sICAM-1 higher in the S group. The levels of the biomarkers Myoglobin and P-Selectin were lower among patients in group M compared to those in groups S and A. Important differences in cytokines and chemokines according to the clinical course were identified. Severe cases presented altered levels when compared to group C. This study helps to characterize biological markers related to angiogenesis, growth factors, heart disease, and cytokine/chemokine production in individuals infected with SARS-CoV-2, offering prognostic signatures and a basis for understanding the biological factors in disease severity., (© 2022. The Author(s).)

The high numbers of COVID-19 cases and deaths in Brazil have made Latin America an epicentre of the pandemic. SARS-CoV-2 established sustained transmission in Brazil early in the pandemic, but important gaps remain in our understanding of virus transmission dynamics at a national scale. We use 17,135 near-complete genomes sampled from 27 Brazilian states and bordering country Paraguay. From March to November 2020, we detected co-circulation of multiple viral lineages that were linked to multiple importations (predominantly from Europe). After November 2020, we detected large, local transmission clusters within the country. In the absence of effective restriction measures, the epidemic progressed, and in January 2021 there was emergence and onward spread, both within and abroad, of variants of concern and variants under monitoring, including Gamma (P.1) and Zeta (P.2). We also characterized a genomic overview of the epidemic in Paraguay and detected evidence of importation of SARS-CoV-2 ancestor lineages and variants of concern from Brazil. Our findings show that genomic surveillance in Brazil enabled assessment of the real-time spread of emerging SARS-CoV-2 variants., (© 2022. The Author(s).)