Seroprevalence of antibodies against SARS-CoV-2 in the school community in Campo Grande, state of Mato Grosso do Sul, Brazil, October 2021-November 2022.

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.

Dengue Fever Surveillance in Mato Grosso do Sul: Insights from Genomic Analysis and Implications for Public Health Strategies.

Since its discovery in early 1916, dengue fever, a common vector-borne illness in Brazil, has resulted in extensive urban outbreaks and poses a serious threat to the public's health. Understanding the dynamics of Dengue Virus (DENV) serotypes circulating in different regions of Brazil is essential for implementing effective disease control and prevention measures. In response to this urgent need, we conducted an on-site training program in genomic surveillance in collaboration with the Central Laboratory of Health and the Secretary of Health of the Mato Grosso do Sul state. This initiative resulted in the generation of 177 DENV genome sequences collected between May 2021 and May 2022, a period during which over 11,391 dengue fever cases were reported in the state. Through this approach, we were able to identify the co-circulation of two different dengue serotypes (DENV1 and DENV2) as well as the existence of diverse viral lineages within each genotype, suggesting that multiple introduction events of different viral strains occurred in the region. By integrating epidemiological data, our findings unveiled temporal fluctuations in the relative abundance of different serotypes throughout various epidemic seasons, highlighting the complex and changing dynamics of DENV transmission throughout time. These findings demonstrate the value of ongoing surveillance activities in tracking viral transmission patterns, monitoring viral evolution, and informing public health actions.

Development and validity assessment of ELISA test with recombinant chimeric protein of SARS-CoV-2.

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.

Hepatitis A virus infection in Brazilian correctional facilities.

Hepatitis A virus (HAV) infection is transmitted by the fecal-oral route, through interpersonal contact and ingestion of contaminated food or water. Prisoners are at higher risk of acquiring HAV infection mainly due to the environment of closed penal institutions and socioeconomic conditions. This study aims to determine the seroprevalence of anti-HAV and its associated risk factors among inmates from twelve prisons in Central Brazil. A cross-sectional study was conducted between March 2013 and March 2014. A total of 580 prisoners participated in the study. The participant's samples were tested for Total and IgM anti-HAV antibodies by electrochemiluminescence immunoassay (ECLIA). Risk factors associated with anti-HAV seropositivity were also analyzed. The prevalence rate of HAV exposure was 88.1% (95% CI: 85.5-90.7). No sample had a positive reaction to IgM anti-HAV. Increasing age, low level of education, and being imprisoned in Corumbá city were independently associated with HAV exposure among prisoners. To prevent the burden of the disease, vaccination strategies should be considered for susceptible prisoners in Central Brazil.

Hepatitis B Virus Infection among Japanese Immigrants and Descendants: The Need to Strengthen Preventive and Control Measures.

This cross-sectional study aimed to investigate the prevalence and risk factors of Hepatitis B virus infection among Japanese immigrants and their descendants from São Paulo (SP), and to verify the occurrence of occult hepatitis B and coinfection with HCV, Delta, and HTLV. All samples (n = 2.127) were tested for HBV serological markers by electrochemiluminescence. HBsAg and/or total anti-HBc positive samples were tested for HBV DNA by real-time PCR, and genotyped by sequencing using the Sanger methodology. The prevalence rate of HBV exposure was 13.4% (CI 95%: 11.9-14.9%), and 22 (1.1%) were HBsAg positive. A high rate of susceptibility to HBV infection was found (67.4%; CI 95%: 65.4-69.4%). In contrast, only 19.2% (CI 95%: 17.6-20.9%) presented a serological profile analogous to that elicited by Hepatitis B vaccination. HBV isolates (n = 8) were classified as genotypes HBV/B1 (62.5%), HBV/C2 (12.5%), HBV/F1b (12.5%), and HBV/A1 (12.5%). Hepatitis B vaccination strategies and educational measures to control this infection should be considered.

Field and classroom initiatives for portable sequence-based monitoring of dengue virus in Brazil.

Brazil experienced a large dengue virus (DENV) epidemic in 2019, highlighting a continuous struggle with effective control and public health preparedness. Using Oxford Nanopore sequencing, we led field and classroom initiatives for the monitoring of DENV in Brazil, generating 227 novel genome sequences of DENV1-2 from 85 municipalities (2015-2019). This equated to an over 50% increase in the number of DENV genomes from Brazil available in public databases. Using both phylogenetic and epidemiological models we retrospectively reconstructed the recent transmission history of DENV1-2. Phylogenetic analysis revealed complex patterns of transmission, with both lineage co-circulation and replacement. We identified two lineages within the DENV2 BR-4 clade, for which we estimated the effective reproduction number and pattern of seasonality. Overall, the surveillance outputs and training initiative described here serve as a proof-of-concept for the utility of real-time portable sequencing for research and local capacity building in the genomic surveillance of emerging viruses.

Dinâmica dos exames realizados no Laboratório Central de Saúde Pública de Mato Grosso do Sul - LACEN/MS ­ para diagnóstico de influenza no período de 2014 a 2016 / Dynamics of the examinations performed at - lacen / ms ­ for the diagnosis of influenza from 2014 to 2016

Este trabalho verificou a dinâmica dos exames realizados para diagnóstico de Influenza no período de 2014 a 2016 e a faixa etária predominante em amostras recebidas pelo LACEN/MS. Objetivo:Avaliar e verificar o aumento no número de exames realizados para diagnóstico de Influenza. Métodos:Os dados foram provenientes de resultados de exames de pacientes de Mato Grosso do Sul realizados no período de 2014 a 2016 pela metodologia de transcriptase reversa, seguida de reação em cadeia de polimerase (RT-PCR) em Tempo Real. Resultados:Foram realizados 4.526 exames para diagnóstico de influenza "A" e "B", sendo detectável em 2014 (12,9%), 2015 (12,5%) e 2016 (40,0%). Verificou-se um aumento de exames nos anos de 2014 e 2016 com predomínio na faixa etária de 20 a 59. Quanto a influenza "A" (H1N1) foram encontrados em 2014, 82;2015, 05;e 2016, 806;sendo a faixa etária de 40 a 59 anos com maior ocorrência.No período de estudo houve 101 óbitos por influenza no estado, sendo em 2016, 63 mortes causadas por H1N1. Conclusão:O estudo permitiu verificar a importância de outras faixas etárias serem incluídas em campanhas de vacinação visando minimizar a incidência de casos confirmados em trabalhadores da faixa etária de 40 a 59 anos e que as políticas de prevenção aliadas a um planejamento estratégico sejam estruturadas garantindo que todos sejam contemplados pela imunização.

This paper verified the dynamics of the tests performed to diagnose Influenza in the period from 2014 to 2016 and the predominant age range in samples received by LACEN / MS. Objective:Evaluate and verify the increase in the examinations for the diagnosis of Influenza.Methods:The data were obtained from the results of patients from Mato Grosso do Sul from 2014 to 2016 by reverse transcriptase methodology, followed by real-time polymerase chain reaction (rRT-PCR). Results:During that period, 4,526 examinations were carried out to diagnose influenza A and B, and could be detected in 2014 (12.9%), 2015 (12.5%) and 2016 (40.0%). There was an increase in the exams in the years of 2014 and2016, with a predominance in the age group from 20 to 59 years old of about 58%. For influenza "A" (H1N1) were found in 2014, 82 (44.0%), 2015, 05 (4.6%) and 2016, 806 (92.0%), being the age group from 40 to 59 the most frequent, 256 (29.2%) were confirmed in 2016, followed by 29 (15.6%) in 2014. In the year 2015, 72 (53.5%) of H3N2 were detected. Influenza "B" ranged from 2.1% (2014) to 29.4% (2015). During the period of this research there were 101 deaths from influenza in the state, being in 2016, 63 deaths caused by H1N1. Conclusion:The study made it possible to verify the importance of other age groups be included in vaccination campaigns in order to minimize the incidence of confirmed cases in workers aged from 40 to 59 years and that prevention policies combined with strategic planning are structured to ensure the immunization to everyone.