RESUMO
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.
Assuntos
COVID-19 , Humanos , Brasil/epidemiologia , COVID-19/epidemiologia , SARS-CoV-2/genética , Mapeamento CromossômicoRESUMO
ABSTRACT. Monoamine oxidase A (MAOA) polymorphisms have been associated with antisocial disorders. Less attention has been paid to the cognitive functioning of individuals with different MAOA alleles. No study has described the cognitive phenotype associated with the less frequent, low enzyme activity allele, MAOA_LPR*2R. Objective: We describe the cognitive correlates of boys having MAOA_LPR*2R allele, ascertained in a sample of school children with normal intelligence, not referred for behavioral disorders. Methods: Participants were eight boys, attending from the second to fifth grades in state-run schools. They were identified among 712 children with typical general cognitive ability, genotyped for MAOA_LPR polymorphism. Participants were assessed with general intelligence, mathematics and spelling achievement, and verbal and visuospatial working memory tests. Neuropsychological performance was compared to published standards, using 1 SD below the mean as a cutoff value for low performance. Results: Intelligence of boys with MAOA_LPR*2R allele varied from above average (N=2) to low average in the other children. Five out of eight boys with the MAOA_LPR*2R allele had low mathematics achievement, and three presented additional difficulties with spelling. Four out of eight children had low short-term and working memory performance. Discussion: This is the first study describing cognitive correlates and school performance in boys having the MAOA_LPR*2R allele. Having this allele, and therefore, probably low MAO-A activity, does not necessarily imply low intelligence or low school performance. However, learning difficulties, particularly in math, and low working memory performance were observed in boys having this allele. This suggests a role of MAOA in learning difficulties.
RESUMO. Polimorfismos da monoaminoxidase A (MAOA) são associados a transtornos antissociais. Menos atenção tem sido dada ao funcionamento cognitivo de indivíduos com diferentes alelos de MAOA. Nenhum estudo descreveu o fenótipo cognitivo associado ao alelo menos frequente, de baixa atividade enzimática, MAOA_LPR*2R. Objetivo: Descrevemos os correlatos cognitivos de meninos com o alelo MAOA_LPR*2R, identificados em uma amostra de escolares com inteligência normal, não encaminhados por transtornos de comportamento. Métodos: Oito meninos com o alelo MAOA_LPR*2R foram identificados entre 712 crianças genotipadas, com inteligência típica, que cursavam do 2º ao 5º ano em escolas públicas. Foram avaliados: inteligência, desempenho em matemática e ortografia, memória de trabalho verbal e visuoespacial. O desempenho foi comparado a normas publicadas, utilizando-se 1 desvio padrão (DP) abaixo da média como ponto de corte para desempenho rebaixado. Resultados: A inteligência dos meninos com alelo MAOA_LPR*2R variou de acima da média (N=2) a médio-inferior nas demais crianças. Cinco dos oito meninos com alelo MAOA_LPR*2R apresentaram desempenho rebaixado em matemática e três apresentaram dificuldades adicionais em ortografia. Quatro dos oito meninos apresentaram baixo desempenho de memória de curto prazo e de trabalho. Discussão: Este é o primeiro estudo a descrever os correlatos cognitivos e o desempenho escolar em meninos com alelo MAOA_LPR*2R. Ter esse alelo não significa necessariamente baixa inteligência ou baixo desempenho escolar. No entanto, dificuldades de aprendizagem, principalmente em matemática, e desempenho rebaixado da memória de trabalho foram observados em mais da metade dos meninos com esse alelo. Isso sugere um papel do MAOA nas dificuldades de aprendizagem.
