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Sci Rep
. 2021 Mar 18;11(1):6233.
doi: 10.1038/s41598-021-85428-7.
Characterizing the Qatar advanced-phase SARS-CoV-2 epidemic
Laith J Abu-Raddad 1 2 3 , Hiam Chemaitelly 4 5 , Houssein H Ayoub 6 , Zaina Al Kanaani 7 , Abdullatif Al Khal 7 , Einas Al Kuwari 7 , Adeel A Butt 7 , Peter Coyle 7 , Andrew Jeremijenko 7 , Anvar Hassan Kaleeckal 7 , Ali Nizar Latif 7 , Robert C Owen 7 , Hanan F Abdul Rahim 8 , Samya A Al Abdulla 9 , Mohamed G Al Kuwari 9 , Mujeeb C Kandy 9 , Hatoun Saeb 9 , Shazia Nadeem N Ahmed 10 , Hamad Eid Al Romaihi 10 , Devendra Bansal 10 , Louise Dalton 10 , Mohamed H Al-Thani 10 , Roberto Bertollini 10
Affiliations
- PMID: 33737535
- DOI: 10.1038/s41598-021-85428-7
Abstract
The overarching objective of this study was to provide the descriptive epidemiology of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic in Qatar by addressing specific research questions through a series of national epidemiologic studies. Sources of data were the centralized and standardized national databases for SARS-CoV-2 infection. By July 10, 2020, 397,577 individuals had been tested for SARS-CoV-2 using polymerase-chain-reaction (PCR), of whom 110,986 were positive, a positivity cumulative rate of 27.9% (95% CI 27.8-28.1%). As of July 5, case severity rate, based on World Health Organization (WHO) severity classification, was 3.4% and case fatality rate was 1.4 per 1,000 persons. Age was by far the strongest predictor of severe, critical, or fatal infection. PCR positivity of nasopharyngeal/oropharyngeal swabs in a national community survey (May 6-7) including 1,307 participants was 14.9% (95% CI 11.5-19.0%); 58.5% of those testing positive were asymptomatic. Across 448 ad-hoc testing campaigns in workplaces and residential areas including 26,715 individuals, pooled mean PCR positivity was 15.6% (95% CI 13.7-17.7%). SARS-CoV-2 antibody prevalence was 24.0% (95% CI 23.3-24.6%) in 32,970 residual clinical blood specimens. Antibody prevalence was only 47.3% (95% CI 46.2-48.5%) in those who had at least one PCR positive result, but 91.3% (95% CI 89.5-92.9%) among those who were PCR positive > 3 weeks before serology testing. Qatar has experienced a large SARS-CoV-2 epidemic that is rapidly declining, apparently due to growing immunity levels in the population.