SARS-CoV-2 seroprevalence in the urban population of Qatar: An analysis of antibody testing on a sample of 112,941 individuals

Peter V Coyle; Hiam Chemaitelly; Mohamed Ali Ben Hadj Kacem; Naema Hassan Abdulla Al Molawi; Reham Awni El Kahlout; Imtiaz Gilliani; Nourah Younes; Ghada Ali A A Al Anssari; Zaina Al Kanaani; Abdullatif Al Khal; Einas Al Kuwari; Adeel A Butt; Andrew Jeremijenko; Anvar Hassan Kaleeckal; Ali Nizar Latif; Riyazuddin Mohammad Shaik; Hanan F Abdul Rahim; Gheyath K Nasrallah; Hadi M Yassine; Mohamed Ghaith Al Kuwari; Hamad Eid Al Romaihi; Mohamed H Al-Thani; Roberto Bertollini; Laith J Abu-Raddad

doi:10.1016/j.isci.2021.102646

SARS-CoV-2 seroprevalence in the urban population of Qatar: An analysis of antibody testing on a sample of 112,941 individuals

iScience. 2021 Jun 25;24(6):102646. doi: 10.1016/j.isci.2021.102646. Epub 2021 May 24.

Authors

Peter V Coyle^{1

2

3}, Hiam Chemaitelly^{4

5}, Mohamed Ali Ben Hadj Kacem¹, Naema Hassan Abdulla Al Molawi¹, Reham Awni El Kahlout¹, Imtiaz Gilliani¹, Nourah Younes¹, Ghada Ali A A Al Anssari¹, Zaina Al Kanaani¹, Abdullatif Al Khal¹, Einas Al Kuwari¹, Adeel A Butt^{1

6}, Andrew Jeremijenko¹, Anvar Hassan Kaleeckal¹, Ali Nizar Latif¹, Riyazuddin Mohammad Shaik¹, Hanan F Abdul Rahim⁷, Gheyath K Nasrallah^{2

8}, Hadi M Yassine^{2

8}, Mohamed Ghaith Al Kuwari⁹, Hamad Eid Al Romaihi¹⁰, Mohamed H Al-Thani¹⁰, Roberto Bertollini¹⁰, Laith J Abu-Raddad^{4

5

6}

Affiliations

¹ Hamad Medical Corporation, Doha, P.O. Box 3050, Qatar.
² Biomedical Research Center, Qatar University, Doha, P.O. Box 2713, Qatar.
³ Wellcome-Wolfson Institute for Experimental Medicine, Queens University, Belfast, BT7 1NN United Kingdom.
⁴ Infectious Disease Epidemiology Group, Weill Cornell Medicine-Qatar, Cornell University, Qatar Foundation - Education City, P.O. Box 24144, Doha, Qatar.
⁵ World Health Organization Collaborating Centre for Disease Epidemiology Analytics on HIV/AIDS, Sexually Transmitted Infections, and Viral Hepatitis, Weill Cornell Medicine-Qatar, Cornell University, Qatar Foundation - Education City, Doha, P.O. Box 24144, Qatar.
⁶ Department of Population Health Sciences, Weill Cornell Medicine, Cornell University, New York, NY 10065, USA.
⁷ College of Health Sciences, QU Health, Qatar University, Doha, P.O. Box 2713, Qatar.
⁸ Department of Biomedical Science, College of Health Sciences, Member of QU Health, Qatar University, Doha, P.O. Box 2713, Qatar.
⁹ Primary Health Care Corporation, Doha, P.O. Box 26555, Qatar.
¹⁰ Ministry of Public Health, Doha, P.O. Box 42, Qatar.

Abstract

The study objective was to the assess level of detectable severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in the urban population of Qatar. Antibody testing was performed on residual blood specimens for 112,941 individuals (∼10% of Qatar's urban population) attending for routine/other clinical care between May 12 and September 9, 2020. Seropositivity was 13.3% (95% confidence interval [CI] = 13.1-13.6%) and was independently associated with sex, age, nationality, clinical care encounter type, and testing date. Median optical density (antibody titer) among antibody-positive persons was 27.0 (range = 1.0-150.0), with higher values associated with age, nationality, clinical care encounter type, and testing date. Seropositivity by nationality was positively correlated with the likelihood of having higher antibody titers (Pearson correlation coefficient = 0.85; 95% CI = 0.47-0.96). Less than two in every 10 individuals in Qatar's urban population had detectable antibodies against SARS-CoV-2, suggesting this population is still far from herd immunity and at risk of subsequent infection waves. Higher antibody titer appears to be a biomarker of repeated exposures to the infection.

Keywords: Health informatics; Immunology; Infection control in health technology; Public health.