Nat. Med. (2021)

Chronic fatigue occurs after SARS and a spectrum of other viral infections. In Nature Medicine, Blomberg et al. report that 81% of 65 hospitalized and 55% of 247 non-hospitalized patients in Bergen, Norway, had persistent symptoms 6 months after infection with SARS-CoV-2. Among the non-hospitalized patients, 83% had symptoms during acute disease; 37% had comorbidities like asthma or COPD (10%), hypertension (8%) and rheumatic disease (4%); and 55% experienced persistent symptoms at 6 months after infection (13% of 0–15 year olds, 50% of 15–30 and 60% of 31–45, 45–60 and over 60). The most frequent lasting symptoms in non-hospitalized patients aged 31–45 and 45–60 were disturbed taste and smell (34 and 28%, respectively), fatigue (31 and 33%), dyspnea (17 and 18%), concentration problems (19 and 21%) and memory problems (16 and 22%). Of non-hospitalized patients over 30, 7% experienced severe fatigue as compared to 24% of hospitalized patients. In non-hospitalized patients, antibody titers at 2 months were associated with the severity of the initial illness, while persistent fatigue was associated with the severity of the initial illness, fever during the initial illness and female gender.