Post-infection symptoms up to 24 months after COVID-19: a matched cohort study in Berlin, Germany

Anne Meierkord ^1,2* Daniel Schulze ³ Maximilian Gertler ¹ Joachim Seybold ⁴ Marcus Mall ^5,6,7 Tobias Kurth ⁸ Frank P Mockenhaupt ¹ Stefanie Theuring ¹

• ¹ Charité Center for Global Health, Charité Universitätsmedizin Berlin, Berlin, Germany
• ² Centre for International Health Protection, Robert Koch Institute, Berlin, Germany
• ³ Institute of Biometry and Clinical Epidemiology, Charité Medical University of Berlin, Berlin, Baden-Württemberg, Germany
• ⁴ Medical Directorate, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
• ⁵ Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charité – Universitätsmedizin Berlin, Berlin, Germany
• ⁶ Berlin Institute of Health (BIH) at Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
• ⁷ German Centre for Lung Research (DZL), associated partner, Berlin, Germany
• ⁸ Institute of Public Health, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany

Introduction. Long-term health consequences after mild COVID-19 are not well described. Our aim was to estimate their prevalence and describe the time course of signs and symptoms for a period of up to 24 months after SARS-CoV-2 infection.Methods. We conducted a cohort study matched for age, sex, and test week among individuals who had attended the public COVID-19 test center at Charité -Universitätsmedizin Berlin, Germany. In early 2022, 576 former COVID-19 patients (>95% non-hospitalised) and 302 uninfected individuals responded to a questionnaire on retrospective monthly symptoms since the test date up to 24 months ago.Results. Symptoms compatible with long COVID were present in 42.9% (247/576) of former COVID-19 patients, compared with 21.2% (64/302) in the uninfected group. In former patients, unadjusted odds ratios (OR) were highest for disturbed taste/smell (OR 9.1 [95% CI: 4.0 -21.1]), memory difficulties (OR 5.1 [95% CI: 2.9 -8.9]), and shortness of breath at rest (OR 4.5 [95% CI: 1.9 -10.6]). In most former COVID-19 patients, symptoms occurred in one coherent period and resolved after a median of 6.5 months, while taste/smell disturbance and neurological/cognitive symptoms showed longer times until recovery. Factors associated with long COVID-compatible symptoms included hospitalisation, symptomatic COVID-19 infection, low household income and female sex.Post-infection symptoms in mild COVID-19 patients mostly persist for about half a year, but sometimes longer. Among uninfected individuals who never experienced COVID-19, 21.2% also reported long COVID-compatible symptoms. The current long COVID definition might require revision to prevent misclassification and over-reporting, and to improve diagnosis and prevalence estimates.