Background Since the end of 2020, there has been a great deal of international concern about the variants of SARS-COV-2 B.1.1.7, identified in the United Kingdom; B.1.351 discovered in South Africa and P.1, originating from the Brazilian state of Amazonas. The three variants were associated with an increase in transmissibility and worsening of the epidemiological situation in the places where they expanded. The lineage B.1.1.7 was associated with the increase in case fatality rate in the United Kingdom. There are still no studies on the case fatality rate of the other two variants. The aim of this study was to analyze the mortality profile before and after the emergence of the P.1 strain in the Amazonas state. Methods We analyzed data from the Influenza Epidemiological Surveillance Information System, SIVEP-Gripe (Sistema de Informação de Vigilância Epidemiológica da Gripe), comparing two distinct epidemiological periods: during the peak of the first wave, between April and May 2020, and in January 2021 (the second wave), the month in which the new variant came to predominate. We calculated mortality rates, overall case fatality rate and case fatality rate among hospitalized patients; all rates were calculated by age and gender and 95% confidence intervals (95% CI) were determined. Findings We observed that in the second wave there were a higher incidence and an increase in the proportion of cases of COVID-19 in the younger age groups. There was also an increase in the proportion of women among Severe Acute Respiratory Infection (SARI) cases from 40% (2,709) in the first wave to 47% (2,898) in the second wave and in the proportion of deaths due to COVID-19 between the two periods varying from 34% (1,051) to 47% (1,724), respectively. In addition, the proportion of deaths among people between 20 and 59 years old has increased in both sexes. The case fatality rate among those hospitalized in the population between 20 and 39 years old during the second wave was 2.7 times the rate observed in the first wave (female rate ratio = 2.71; 95% CI: 1.9-3.9], p <0.0001; male rate ratio = 2.70, 95%CI:2.0-3.7), and in the general population the rate ratios were 1.15 (95% CI: 1.1-1.2) in females and 0.78 (95% CI: 0.7-0.8) in males]. Interpretation Based on this prompt analysis of the epidemiological scenario in the Amazonas state, the observed changes in the pattern of mortality due to COVID-19 between age groups and gender simultaneously with the emergence of the P.1 strain suggest changes in the pathogenicity and virulence profile of this new variant. Further studies are needed to better understanding of SARS-CoV-2 variants profile and their impact for the health population.

Introdução Desde o final de 2020 tem havido grande preocupação internacional com as variantes do SARS-COV-2: B.1.1.7, identificada no Reino Unido; B.1.351, descoberta na África do Sul e P.1, que emergiu inicialmente estado brasileiro do Amazonas. As três variantes foram associadas a aumento na transmissibilidade e piora da situação epidemiológica nos locais onde se expandiram. A linhagem B.1.1.7 foi associada ao aumento da taxa de letalidade no Reino Unido. Ainda não existem estudos conclusivos sobre letalidade das outras duas variantes. O objetivo deste estudo foi analisar o perfil de mortalidade antes e depois da emergência da linhagem P.1 no Amazonas. Métodos Analisamos os dados do sistema nacional de vigilância epidemiológica, comparando dois momentos epidemiológicos distintos: durante o pico da primeira onda, entre abril e maio de 2020, e em janeiro de 2021, mês em que a nova variante passou a predominar. Calculamos as taxas de mortalidade, letalidade e letalidade entre pacientes internados, todas as taxas foram calculadas por idade e por sexo e determinados os intervalos de confiança de 95%. Achados Observamos que na segunda onda houve maior incidência e aumento na proporção de casos de COVID-19 nas faixas etárias mais jovens. Observou-se, também, um aumento na proporção de mulheres entre os casos de SARI de 40% (2.709) na primeira onda para 47% (2.898) na segunda onda e entre mortes por COVID-19 de 34% (1,051) para 47% (1.724), respectivamente. Além disso, a proporção de mortes entre 20 e 59 anos aumentou em ambos os sexos. A letalidade entre os hospitalizados na população entre 20 e 39 anos durante a segunda onda foi 2.7 vezes a primeira onda [razão de taxas sexo feminino=2,71; CI(95%)=1,9-3,9], p<0.0001; razão de taxas sexo masculino=2.70(2.0-3.7)), na população geral as razões de taxa foram 1,15(1,1-1,2) no sexo feminino e 0,78(0,7-0,8) no sexo masculino. Interpretação Observamos mudanças no padrão de mortalidade por COVID-19 entre as faixas etárias e sexo simultaneamente à emergência da linhagem P.1, sugerindo mudanças nos perfis de patogenicidade e virulência, novos estudos são necessários para melhor compreensão das variantes do SARS-CoV-2 e suas consequências na saúde da população.

A new coronavirus [severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)] is currently causing a life-threatening pandemic. In this study, we report the complete genome sequencing and genetic characterisation of a SARS-CoV-2 detected in Manaus, Amazonas, Brazil, and the protocol we designed to generate high-quality SARS-CoV-2 full genome data. The isolate was obtained from an asymptomatic carrier returning from Madrid, Spain. Nucleotide sequence analysis showed a total of nine mutations in comparison with the original human case in Wuhan, China, and support this case as belonging to the recently proposed lineage A.2. Phylogeographic analysis further confirmed the likely European origin of this case. To our knowledge, this is the first SARS-CoV-2 genome obtained from the North Brazilian Region. We believe that the information generated in this study may contribute to the ongoing efforts toward the SARS-CoV-2 emergence.