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

Sávio Luiz Pereira Nunes; Chirles Araújo de França; Gabriela Dias Rocha; Samily Aquino de Sá Oliveira; Mariana Ramos Freitas; Eliane Oliveira da Silva; Katia Sampaio Coutinho; Aline Silva Jerônimo; Gustavo Barbosa de Lima; Raul Emídio de Lima; Matheus Filgueira Bezerra; Filipe Zimmer Dezordi; Marcelo Henrique Santos Paiva; Gabriel da Luz Wallau; Carlos Dornels Freire de Souza; Anderson da Costa Armstrong; Rodrigo Feliciano do Carmo

doi:10.1016/j.heliyon.2023.e18994

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

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

Authors

Sávio Luiz Pereira Nunes¹, Chirles Araújo de França², Gabriela Dias Rocha^{1

2}, Samily Aquino de Sá Oliveira², Mariana Ramos Freitas², Eliane Oliveira da Silva³, Katia Sampaio Coutinho³, Aline Silva Jerônimo³, Gustavo Barbosa de Lima⁴, Raul Emídio de Lima⁴, Matheus Filgueira Bezerra⁵, Filipe Zimmer Dezordi^{6

7}, Marcelo Henrique Santos Paiva^{6

8}, Gabriel da Luz Wallau^{6

7

9}, Carlos Dornels Freire de Souza¹⁰, Anderson da Costa Armstrong¹⁰, Rodrigo Feliciano do Carmo^{1

11}

Affiliations

¹ Postgraduate Program in Applied Cellular and Molecular Biology, University of Pernambuco (UPE), Recife, Pernambuco, Brazil.
² Multi-User Research Laboratory (LAMUPE), Dr. Washington Antônio de Barros Hospital - EBSERH/UNIVASF, Petrolina, Pernambuco, Brazil.
³ VIII Regional Health Management, State Health Secretariat of Pernambuco, Petrolina, Pernambuco, Brazil.
⁴ Technology Platforms Center (NPT), Aggeu Magalhães Institute (IAM), FIOCRUZ-Pernambuco, Recife, Pernambuco, Brazil.
⁵ Departament of Microbiology, Aggeu Magalhães Institute (IAM), FIOCRUZ-Pernambuco, Recife, Pernambuco, Brazil.
⁶ Departament of Entomology, Aggeu Magalhães Institute (IAM)- FIOCRUZ-Pernambuco, Recife, Pernambuco, Brazil.
⁷ Bioinformatics Center (NBI), Aggeu Magalhães Institute (IAM), FIOCRUZ-Pernambuco, Recife, Pernambuco, Brazil.
⁸ Life Sciences Center, Federal University of Pernambuco (UFPE), Caruaru, Pernambuco, Brazil.
⁹ Department of Arbovirology, Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Center for Arbovirus and Hemorrhagic Fever Reference and Research, National Reference Center for Tropical Infectious Diseases, Hamburg, Germany.
¹⁰ Collegiate of Medicine, Federal University of the São Francisco Valley - UNIVASF, Petrolina, Pernambuco, Brazil.
¹¹ Collegiate of Pharmaceutical Sciences, Federal University of the São Francisco Valley - UNIVASF, Petrolina, Pernambuco, Brazil.

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.