COVID-19 and Its Symptoms' Panoply: A Case-Control Study of 919 Suspected Cases in Locked-Down Ovar, Portugal [COVID-19 e a sua panoplia de sintomas: um estudo caso-controlo de 919 casos suspeitos durante o cordão sanitàrio de Ovar, Portugal]

• Type: Article in National Scientific Journal
• Date: 2021

Authors

Sá, R (Author) Other; Pinho Bandeira, T (Author) Other; Queiroz, G (Author) Other; Matos, J (Author) Other; Ferreira, JD (Author) Other; Pedro Pereira Rodrigues (Author) FMUP

Journal

Title: Portuguese Journal of Public Health

Publisher: Karger

Indexing

Scopus - 0 Citations

Other information

Authenticus ID: P-00T-GFP

DOI: 10.1159/000514925

Abstract (EN): Background: Ovar was the first Portuguese municipality to declare active community transmission of SARS-CoV-2, with total lockdown decreed on March 17, 2020. This context provided conditions for a large-scale testing strategy, allowing a referral system considering other symptoms besides the ones that were part of the case definition (fever, cough, and dyspnea). This study aims to identify other symptoms associated with COVID-19 since it may clarify the pre-test probability of the occurrence of the disease. Methods: This case-control study uses primary care registers between March 29 and May 10, 2020 in Ovar municipality. Pre-test clinical and exposure-risk characteristics, reported by physicians, were collected through a form, and linked with their laboratory result. Results: The study population included a total of 919 patients, of whom 226 (24.6%) were COVID-19 cases and 693 were negative for SARS-CoV-2. Only 27.1% of the patients reporting contact with a confirmed or suspected case tested positive. In the multivariate analysis, statistical significance was obtained for headaches (OR 0.558), odynophagia (OR 0.273), anosmia (OR 2.360), and other symptoms (OR 2.157). The interaction of anosmia and odynophagia appeared as possibly relevant with a borderline statistically significant OR of 3.375. Conclusion: COVID-19 has a wide range of symptoms. Of the myriad described, the present study highlights anosmia itself and calls for additional studies on the interaction between anosmia and odynophagia. Headaches and odynophagia by themselves are not associated with an increased risk for the disease. These findings may help clinicians in deciding when to test, especially when other diseases with similar symptoms are more prevalent, namely in winter.

Language: English

Type (Professor's evaluation): Scientific