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The introduction of SARS-CoV-2 variants of concern (VOCs) in Brazil has been associated with major impacts on the epidemiological and public health scenario. In this study, 291,571 samples were investigated for SARS-CoV-2 variants from August 2021 to March 2022 (the highest peak of positive cases) in four geographical regions of Brazil. To identify the frequency, introduction, and dispersion of SARS-CoV-2 variants in 12 Brazilian capitals, VOCs defining spike mutations were identified in 35,735 samples through genotyping and viral genome sequencing. Omicron VOC was detected in late November 2021 and replaced the Delta VOC in approximately 3.5 weeks. We estimated viral load differences between SARS-CoV-2 Delta and Omicron through the evaluation of the RT-qPCR cycle threshold (Ct) score in 77,262 samples. The analysis demonstrated that the Omicron VOC has a lower viral load in infected patients than the Delta VOC. Analyses of clinical outcomes in 17,586 patients across the country indicated that individuals infected with Omicron were less likely to need ventilatory support. The results of our study reinforce the importance of surveillance programs at the national level and showed the introduction and faster dispersion of Omicron over Delta VOC in Brazil without increasing the numbers of severe cases of COVID-19. [ABSTRACT FROM AUTHOR]

Brazil currently ranks second in absolute deaths by COVID-19, even though most of its population has completed the vaccination protocol. With the introduction of Omicron in late 2021, the number of COVID-19 cases soared once again in the country. We investigated in this work how lineages BA.1 and BA.2 entered and spread in the country by sequencing 2173 new SARS-CoV-2 genomes collected between October 2021 and April 2022 and analyzing them in addition to more than 18,000 publicly available sequences with phylodynamic methods. We registered that Omicron was present in Brazil as early as 16 November 2021 and by January 2022 was already more than 99% of samples. More importantly, we detected that Omicron has been mostly imported through the state of São Paulo, which in turn dispersed the lineages to other states and regions of Brazil. This knowledge can be used to implement more efficient non-pharmaceutical interventions against the introduction of new SARS-CoV variants focused on surveillance of airports and ground transportation. [ABSTRACT FROM AUTHOR]

Since its first identification in Brazil, the variant of concern (VOC) Gamma has been associated with increased infection and transmission rates, hospitalizations, and deaths. Minas Gerais (MG), the second-largest populated Brazilian state with more than 20 million inhabitants, observed a peak of cases and deaths in March-April 2021. We conducted a surveillance study in 1240 COVID-19-positive samples from 305 municipalities distributed across MG's 28 Regional Health Units (RHU) between 1 March to 27 April 2021. The most common variant was the VOC Gamma (71.2%), followed by the variant of interest (VOI) zeta (12.4%) and VOC alpha (9.6%). Although the predominance of Gamma was found in most of the RHUs, clusters of Zeta and Alpha variants were observed. One Alpha-clustered RHU has a history of high human mobility from countries with Alpha predominance. Other less frequent lineages, such as P.4, P.5, and P.7, were also identified. With our genomic characterization approach, we estimated the introduction of Gamma on 7 January 2021, at RHU Belo Horizonte. Differences in mortality between the Zeta, Gamma and Alpha variants were not observed. We reinforce the importance of vaccination programs to prevent severe cases and deaths during transmission peaks.

The quantification of viral nucleic acids in serum by real-time PCR plays an important role in diagnosing hepatitis B virus and hepatitis C virus infection. In this study, we developed an assay using specific primers and probes to quantify hepatitis B virus DNA or hepatitis C virus RNA in serum from infected patients. For standardization and validation of the assay, an international panel of hepatitis B virus/hepatitis C virus and standard plasmids was used. A correlation coefficient of 0.983 and 0.963 for hepatitis B virus and hepatitis C virus, respectively, was obtained based on cycle threshold values and concentrations of DNA or RNA. The standard curve showed a linear relationship from 19IU/mL to 1.9×10 9 IU/mL of serum, with a coefficient of determination (r 2 ) of 0.99. In sera from patients infected with hepatitis B virus or hepatitis C virus viral loads (19IU/mL and 1.9×10 9 IU/mL), we quantified viral loads with a detection limit of 1.9×10 2 IU/mL. The real-time quantitative PCR assay developed in this study provides an ideal system for routine diagnosis and confirmation of indeterminate serological results, especially in immunosuppressed patients., (Copyright © 2016. Published by Elsevier Editora Ltda.)

This study provides population genetic data for individuals of Vitoria, Espirito Santo, Brazil, a location not yet characterized for STR frequencies used for genetic identification studies. Allelic frequencies and other population data analysis are reported for the 15 autosomal-STR loci included in the PowerPlex(®)16 kit (CSF1PO, D13S317, D16S539, D18S51, D21S11, D3S1358, D5S818, D7S820, D8S1179, FGA, Penta D, Penta E, TPOX, TH01 and vWA). Allele and haplotype frequencies, gene diversity and discrimination capacity were also estimated for the PowerPlex(®) Y System (DYS19, DYS385, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438 and DYS439). Blood samples were obtained from 226 unrelated volunteers (135 males and 91 females) residents in the city of Vitoria, representing a typical sample of the mixed ethnicity present in the Espirito Santo State, Brazil. Within the tested population, the total number of individuals typed for specific markers is: 226 for D13S317, D21S11, D3S1358, D7S820, D8S1179 and FGA; 225 for D16S539 and D5S818; 224 for D18S51; 223 for CSF1PO; 222 for Penta D and vWA; 220 for Penta E; 207 for TPOX and 142 for TH01. Y-STR haplotypes were analyzed for 102 unrelated males, being 71 of them present in the 135 autosomal-STR sample, and 31 new males tested only for Y-STR markers. All autosomal markers were in Hardy-Weinberg Equilibrium. Y-STR analysis identified 101 haplotypes, being 100 of them unique., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)