Day by day symptoms following positive and negative PCR tests for SARS-CoV-2 in non-hospitalized health-care workers: a 90-day follow-up study

Nielsen, K. J.; Vestergaard, J. M.; Schlünssen, V.; Bonde, J. P.; Kaspersen, K. A.; Biering, K.; Carstensen, O.; Greve, T.; Hansen, K. K.; Dalboge, A.; Flachs, E. M.; Jespersen, S.; Hansen, M. L.; Mikkelsen, S.; Thomsen, M. K.; Redder, J. D.; Würtz, E. T.; Ostergaard, L.; Erikstrup, C.; Kolstad, H. A.

Background: Little is known about the long-term course of symptoms for mild coronavirus disease 2019 (COVID-19) when accounting for symptoms due to other causes. We aimed to compare symptoms day by day for non-hospitalised individuals who tested positive and negative with polymerase chain reaction for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods: We followed 210 test-positive and 630 individually matched test-negative healthcare workers of the Central Denmark Region up to 90 days after the test, April-June 2020. They daily reported seven COVID-19 related symptoms. Symptom courses were compared graphically and by conditional multivariable logistic regression. Results: Thirty % of test-positive and close to zero of test-negative participants reported a reduced sense of taste and smell during all 90 days of follow-up (adjusted odds ratio [aOR] 86.07, 95% CI 22.86-323). Dyspnoea was reported by an initial 20% of test-positive with a gradual decline to about 5% after 30 days without ever reaching the level of the test-negative participants (aOR 6.88, 95% CI 2.41-19.63). Cough, headache, sore throat, muscle aches, and fever were temporarily more prevalent among the test positive participants, but after 30 days, no increases were seen. Women and participants aged 45 years or older tended to be more susceptible to SARS-CoV-2 infection. Conclusion: Prevalence of long-lasting reduced sense of taste and smell is highly increased after being diagnosed with mild COVID-19. This pattern is also seen for dyspnoea at a low level but not for cough, sore throat, headache, muscle ache or pain, or fever.