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. 2023 Aug 6;9(8):e18994.
doi: 10.1016/j.heliyon.2023.e18994. eCollection 2023 Aug.

Assessment of clinical characteristics and viral load in individuals infected by Delta and Omicron variants of SARS-CoV-2

Sávio Luiz Pereira Nunes  1 , Chirles Araújo de França  2 , Gabriela Dias Rocha  1   2 , Samily Aquino de Sá Oliveira  2 , Mariana Ramos Freitas  2 , Eliane Oliveira da Silva  3 , Katia Sampaio Coutinho  3 , Aline Silva Jerônimo  3 , Gustavo Barbosa de Lima  4 , Raul Emídio de Lima  4 , Matheus Filgueira Bezerra  5 , Filipe Zimmer Dezordi  6   7 , Marcelo Henrique Santos Paiva  6   8 , Gabriel da Luz Wallau  6   7   9 , Carlos Dornels Freire de Souza  10 , Anderson da Costa Armstrong  10 , Rodrigo Feliciano do Carmo  1   11
Affiliations

Assessment of clinical characteristics and viral load in individuals infected by Delta and Omicron variants of SARS-CoV-2

Sávio Luiz Pereira Nunes et al. Heliyon. .

Abstract

In late 2021, a new variant of SARS-CoV-2 called Omicron emerged, replacing Delta worldwide. Although it has been associated with a lower risk of hospitalization and severe forms of COVID-19, there is little evidence of its relationship with specific symptoms and viral load. The aim of this study was to verify the relationship between Delta and Omicron variants of concern, viral load, and the occurrence of symptoms in individuals with COVID-19. Nasopharyngeal swab samples were collected and sequenced from patients with COVID-19 from the Northeast Region of Brazil between August 2021 and March 2022. The results showed a gradual replacement of the Delta variant by the Omicron variant during the study period. A total of 316 samples (157 Delta and 159 Omicron) were included. There was a higher prevalence of symptoms in Delta-infected individuals, such as coryza, olfactory and taste disturbances, headache, and myalgia. There was no association between viral load and the variants analyzed. The results reported here contribute to the understanding of the symptoms associated with the Delta and Omicron variants in individuals affected by COVID-19.

Keywords: COVID-19; Delta; Omicron; Symptoms; Variants of concern; Viral load.

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Conflict of interest statement

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Rodrigo Feliciano do Carmo reports financial support was provided by Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco (FACEPE). Associate Editor of Heliyon - Rodrigo Feliciano do Carmo.

Figures

Fig. 1
Fig. 1
Flow chart of the samples included in the study.
Fig. 2
Fig. 2
Circulation dynamics of SARS-CoV-2 variants among the samples analyzed from August 2021 to March 2022.
Fig. 3
Fig. 3
Threshold cycle (Ct) values between Delta and Omicron variants of SARS-CoV-2 in nasopharyngeal swab specimens. A) gene E, B) gene N. Comparison performed by Mann-Whitney test.
See this image and copyright information in PMC

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