Papers of the Week

Knowledge of the clinical course and consequences of COVID-19 initially evolved in the context of severe presentations and among those with comorbidities. However, understanding the outcomes of milder infections in healthy individuals is important for safe return-to-duty in extreme environments or to occupations requiring significant fitness. We reviewed the literature to characterize the nature and timing of persistent and emergent clinical sequelae in milder COVID-19 cases to facilitate development of post-COVID-19 screening and surveillance protocols. We searched databases including EMBASE, MEDLINE, Cochrane COVID-19 study register, gray literature, clinical trial registries, and relevant health and disease prevention sources for publications from 2019 to February 18, 2021, documenting COVID-19 sequelae. Articles were included if the COVID-19 severity was mild and there were no, or only minor, pre-existing comorbidities. Persistent and emergent sequelae were then stratified based on time since diagnosis. Among those with mild COVID-19, sequelae were shown to emerge or persist for months following presumed recovery. Among those with no comorbidities, cardiac, hematological, and respiratory sequelae emerged after 1-2 mo, and primarily cardiac abnormalities persisted at ≥ 3 mo. Among those with minor comorbidities, persistent respiratory abnormalities, fatigue, dyspnea, and headache were common, and mental health symptoms emerged by 1-2 mo postinfection. After presumed recovery from mild COVID-19, a range of symptoms can persist and later emerge. Whether these are new or previously unrecognized is unclear. Under-recognized COVID-19 sequelae may increase the risk of subtle or sudden incapacitation and have implications for return-to-work (RTW) screening and surveillance for safety-critical roles.