A variable proportion of patients develop persistent/prolonged symptoms of Coronavirus Disease 2019 (COVID-19) infection (long COVID). We aimed to study the clinical predictors of persistent symptoms in patients with mild COVID-19 at 30 days post discharge (long COVID-19). We also tried to identify symptom clusters among mild COVID-19 patients. Fifty-seven patients admitted at a tertiary care centre after a positive RT-PCR report over a period of 2 months, were enrolled in the study. Details of presentation, history of illness, laboratory investigations and disease outcomes were recorded from documented medical records and discharge slip. The patients were contacted (telephonically) at 30 days after discharge and enquired regarding persistent symptoms, if any. Follow up data at 30 days post-discharge was available for 53 patients. Among them, the most common persistent symptom was fatigue (22.6%), followed by cough (9.4%) and myalgias (7.5%). There was a significant association of persistent symptoms with diarrhoea at presentation [OR 14.26 (95% CI 2.30-142.47; p = 0.009] and gap between symptom onset and admission [OR 1.40 (95% CI 1.08-1.93; p = 0.020] on multivariate logistic regression analysis. On cluster analysis, three phenotypes of mild COVID-19 were identified, which may have implications on monitoring and management. There appears to be a positive association of diarrhoea as a presenting manifestation and gap between symptom onset and admission with the persistence of symptoms classified as long COVID-19, even in mild illness. We also identified multiple phenotypes of mild COVID-19 illness, which warrant further exploration.
Keywords: COVID-19; long COVID; phenotypes; predictors.