Long COVID-19 syndrome: a 14-months longitudinal study during the two first epidemic peaks in Southeast Brazil

A growing number of long COVID cases after infection have been reported. By definition, long COVID is the condition whereby affected individuals do not recover for several weeks or months following the onset of symptoms suggestive of COVID-19, the profile and timeline of which remains uncertain.

In this work, in-home, outpatient and hospitalized COVID-19 positive patients were monitored for up to 14 mo to establish the prevalence of long COVID symptoms and their correlation with age, pre-existing comorbidities and course of acute infection. The longitudinal study included 646 positive patients who were monitored once a month.

From the whole population, 50.2% presented with long COVID syndrome. Twenty-three different symptoms were reported. Most frequent were fatigue (35.6%), persistent cough (34.0%), dyspnea (26.5%), loss of smell/taste (20.1%) and frequent headaches (17.3%). Mental disorders (20.7%), change in blood pressure (7.4%) and thrombosis (6.2%) were also reported. Most patients presented with 2-3 symptoms at the same time. Long COVID started after mild, moderate and severe infection in 60, 13 and 27% of cases, respectively, and it was not restricted to specific age groups.

Older patients tended to have more severe symptoms, leading to a longer post-COVID-19 period. The presence of seven comorbidities was correlated with the severity of infection, and severity itself was the main factor that determined the duration of symptoms in long COVID cases.