Long-term symptoms after SARS-CoV-2 infection in a cohort of hospital employees: duration and predictive factors

Objective: To evaluate the frequency, duration and patterns of long-term coronavirus disease 2019 (COVID-19) symptoms and to analyze risk factors for long-lasting COVID-19 sequelae among hospital employees (HEs). Design: Retrospective observational cohort study. Setting: Three medical centers in Cologne, Germany. Participants: We included HEs who had a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) test between March 2020 and May 2021. Methods: We conducted a survey in mid-2021 with all HEs tested SARS-CoV-2 PCR positive during the study period and asked about the presence and duration of 24 different COVID-19 related symptoms. Chronological development and patterns of symptom complexes, probability of symptom persistence and possible risk factors for protracted COVID-19 course were analyzed. Results: Of 221 included HEs, a number of 104 HEs (47.1%) reported at least one persisting symptom for more than 90 days after initial SARS-CoV-2 detection. A symptom duration over 28 days was associated with multiple symptom complexes. The most common was the interrelated occurrence of shortness of breath, memory disorder, concentration disorders and fatigue. Each one cycle higher initial Ct value significantly increased the chances of overcoming symptoms (odds ratio [OR] = 1.05; p = 0.019). The occurrence of breathlessness within the first ten days (OR = 7.89; p = 0.008), an initial Ct value under 30 (OR = 3.36; p = 0.022) and a definitely nosocomial SARS-CoV-2 transmission (OR = 3.05; p = 0.049) showed a statistically significant association with increased odds of illness duration over 90 days. Conclusion: About half of the HEs suffered from long lasting symptoms over 90 days after almost entirely mild acute COVID-19. Different symptom complexes could be shown and predictive factors for long-term symptoms were identified. Predictive factors at the onset of the infection could possibly be used for early treatment to prevent development of long-term symptoms after COVID-19 in future.