Análise filogenética da variante Delta do SARS-CoV-2 circulante no Estado do Rio Grande do Norte

Abstract

Severe acute respiratory syndrome-associated coronavirus 2 (SARS-CoV-2), classified in the Betacoronavirus genus and Sarbecovirus subgenus. This virus is the etiological agent that causes the disease COVID-19, which consists of a potentially serious respiratory infection that emerged in late 2019, established itself as a pandemic in early 2020 and remains to this day. According to the World Health Organization, the Delta variant of SARS-CoV-2, first detected in India in October 2020, spread to many countries quickly and was the main factor causing the third wave of the virus pandemic in July 2021. The objective of this work was to carry out a phylogenetic and phylogeographic analysis of the delta variant of SARS-CoV-2 in Rio Grande do Norte, in order to know its phylodynamics. For this, nasal secretion samples from patients suspected of being infected by SARS-CoV-2, from different regions of Rio Grande do Norte, underwent the viral RNA extraction process and were subjected to reverse transcription followed by amplification by the Chain Reaction. of polymerase in real time at the Central Public Health Laboratory of Rio Grande do Norte. Then, the positive samples were sent to Instituto Oswaldo Cruz (Rio de Janeiro), for molecular characterization through genetic sequencing and deposited in the Global Initiative on Sharing Avian Influenza Data (GISAID) platform, where data were collected for analysis. phylogenetic and phylogeographic. This analysis indicated that the delta variant had several introductions in Brazil at different times and places in August 2021, in Amazonas and Amapá. In the same period, it was detected in Rio Grande do Norte, in the municipalities of Parnamirim, Equador, Extremoz, Canguaretama, Macaíba, Parazinho, Natal, Touros and Cerro Corá. There is a hypothesis that this variant of the virus was introduced in São Paulo and Rio de Janeiro, where community transmission began and from there it spread across the country. This study showed that this variant quickly spread throughout all regions of Brazil, as it did in other countries. This shows that the epidemiological behavior of the virus is the same on a global scale, hence the importance of molecular surveillance and analysis of evolution on a continuous basis.