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. 2021 Feb 19:149:e54.
doi: 10.1017/S095026882100042X.

COVID-19 symptoms: a case-control study, Portugal, March-April 2020

M Perez Duque  1   2   3 , H Lucaccioni  1   2 , C Costa  1 , R Marques  1 , D Antunes  3 , L Hansen  4 , R Sá Machado  1
Affiliations

COVID-19 symptoms: a case-control study, Portugal, March-April 2020

M Perez Duque et al. Epidemiol Infect. .

Abstract

COVID-19, although a respiratory illness, has been clinically associated with non-respiratory symptoms. We conducted a negative case-control study to identify the symptoms associated with SARS-CoV-2-positive results in Portugal. Twelve symptoms and signs included in the clinical notification of COVID-19 were selected as predictors, and the dependent variable was the RT-PCR test result. The χ2 tests were used to compare notified cases on sex, age group, health region and presence of comorbidities. The best-fit prediction model was selected using a backward stepwise method with an unconditional logistic regression. General and gastrointestinal symptoms were strongly associated with a positive test (P < 0.001). In this sense, the inclusion of general symptoms such as myalgia, headache and fatigue, as well as diarrhoea, together with actual clinical criteria for suspected cases, already updated and included in COVID-19 case definition, can lead to increased identification of cases and represent an effective strength for transmission control.

Keywords: Case–control study; coronavirus; symptoms.

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Conflict of interest statement

None.

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References

    1. Rothan HA and Byrareddy SN (2020) The epidemiology and pathogenesis of coronavirus disease (COVID-19) outbreak. Journal of Autoimmunity [Internet] 109, 102433. Available at http://www.sciencedirect.com/science/article/pii/S0896841120300469. - PMC - PubMed
    1. Huang C et al. (2020) Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet (London, England) [Internet]. 2020/01/24 395, 497–506. Available at https://pubmed.ncbi.nlm.nih.gov/31986264. - PMC - PubMed
    1. Pascarella G et al. (2020) COVID-19 diagnosis and management: a comprehensive review. Journal of Internal Medicine [Internet] 288(2), 192–206. Available at: https://onlinelibrary.wiley.com/doi/abs/10.1111/joim.13091. - PMC - PubMed
    1. Sanders JM et al. (2020) Pharmacologic treatments for coronavirus disease 2019 (COVID-19): a review. JAMA – Journal of the American Medical Association 323(18), 1824–1836. - PubMed
    1. Nobel YR et al.. (2020) Gastrointestinal symptoms and COVID-19: case-control study from the United States. Gastroenterology 159(1), 373–375.e2. - PMC - PubMed