Epidemiological investigation of the first 5685 cases of SARS-CoV-2 infection in Qatar, 28 February–18 April 2020

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Abstract

To define the epidemiological curve of COVID-19 in Qatar and determine factors associated with severe or critical illness.

Design

Case series of first 5685 COVID-19 cases in Qatar.

Setting and participants

All confirmed COVID-19 cases in the State of Qatar between 28 February and 18 April 2020.

Main outcome measures

Number of total and daily new COVID-19 infections; demographic characteristics and comorbidity burden and severity of infection; factors associated with severe or critical illness.

Results

Between 28 February and 18 April 2020, 5685 cases of COVID-19 were identified. Median age was 34 (IQR 28–43) years, 88.9% were male and 8.7% were Qatari nationals. Overall, 83.6% had no concomitant comorbidity, and 3.0% had three or more comorbidities. The overwhelming majority (90.9%) were asymptomatic or with minimal symptoms, with 2.0% having severe or critical illness. Seven deaths were observed during the time interval studied. Presence of hypertension or diabetes was associated with a higher risk of severe or critical illness, but age was not. The epidemiological curve indicated two distinct patterns of infection, a larger cluster among expatriate craft and manual workers and a smaller one among Qatari nationals returning from abroad during the epidemic.

Conclusion

COVID-19 infections in Qatar started in two distinct clusters, but then became more widespread in the population through community transmission. Infections were mostly asymptomatic or with minimal symptoms and associated with very low mortality. Severe/critical illness was associated with presence of hypertension or diabetes but not with increasing age.

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  1. SciScore for 10.1101/2020.07.15.20154211: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board StatementIRB: Baseline was the median value, for the corresponding day of the week, during the 5-week period between January 3, 2020 and February 6, 2020.17 Ethical Approval: The Institutional Review Board at Hamad Medical Corporation approved this study with an expedited status due to the emergency pandemic status of the COVID-19 outbreak.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    No key resources detected.


    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).


    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    There are limitations to our study. Comorbidities were retrieved from the electronic medical records using ICD-10 AM codes. Exact geographic location and contact tracing data were not included in the current report. Our study end date was April 18, 2020, and all persons with confirmed infection till that date were included. However, it is possible that some persons may have progressed to more severe disease after this date. In conclusion, we describe the evolution of COVID-19 epidemic in the State of Qatar. The epidemic predominantly affected males and younger population and was associated with no or minimal symptoms in a vast majority of the infected persons. Public health measures were instituted early and may have led to the slower growth compared with other countries which delayed such measures.

    Results from TrialIdentifier: No clinical trial numbers were referenced.


    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.


    Results from JetFighter: We did not find any issues relating to colormaps.


    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

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