Seroprevalence of COVID-19 in Riyadh city during the early increase of COVID-19 infections in Saudi Arabia, June 2020

Mohammed W Alenazi; Abdullah Algaisi; Hosam M Zowawi; Omar Aldibasi; Anwar M Hashem; Naif Khalaf Alharbi

doi:10.1016/j.sjbs.2022.103282

Seroprevalence of COVID-19 in Riyadh city during the early increase of COVID-19 infections in Saudi Arabia, June 2020

Saudi J Biol Sci. 2022 Jun;29(6):103282. doi: 10.1016/j.sjbs.2022.103282. Epub 2022 Apr 22.

Authors

Mohammed W Alenazi^{1

2}, Abdullah Algaisi³, Hosam M Zowawi^{1

2}, Omar Aldibasi^{1

2}, Anwar M Hashem^{4

5}, Naif Khalaf Alharbi^{1

2}

Affiliations

¹ King Abdullah International Medical Research Center, Riyadh, Saudi Arabia.
² King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.
³ Department of Medical Laboratories Technology, College of Applied Medical Sciences, Medical Research Center, Jazan University, Jazan 45142, Saudi Arabia.
⁴ Department of Medical Microbiology and Parasitology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.
⁵ Vaccines and Immunotherapy Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.

Abstract

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) emerged in December 2019 and caused a global pandemic of the Coronavirus Disease 2019 (COVID-19). More than 170 million cases have been reported worldwide with mortality rate of 1-3%. The detection of SARS-CoV-2 by molecular testing is limited to acute infections, therefore serological studies provide a better estimation of the virus spread in a population. This study aims to evaluate the seroprevalence of SARS-CoV-2 in the major city of Riyadh, Saudi Arabia during the sharp increase of the pandemic, in June 2020. Serum samples from non-COVID patients (n = 432), patients visiting hospitals for other complications and confirmed negative for COVID-19, and healthy blood donors (n = 350) were collected and evaluated using an in-house enzyme-linked immunosorbent assay (ELISA). The overall percentage of positive samples was 7.80% in the combined two populations (n = 782). The seroprevalence was lower in the blood donors (6%) than non-COVID-19 patients (9.25%), p = 0.0004. This seroprevalence rate is higher than the documented cases, indicating asymptomatic or mild unreported COVID-19 infections in these two populations. This warrants further national sero-surveys and highlights the importance of real-time serological surveillance during pandemics.

Keywords: Blood donors; COVID-19; ELISA; SARS-CoV-2; Seroprevalence.