Persistent symptoms after a Covid-19: current state of knowledge

The lungs are the main organ for SARS-CoV-2 infection and the obvious prognostic factor in the acute phase; however, the virus can spread to many different organs, including the heart, blood vessels, gastrointestinal tract, liver, central nervous system and kidneys. Since the beginning of the pandemic, persistent symptoms after Covid-19 have been reported, as it was the case in the SARS-CoV-1 epidemic, including in people who initially suffered from a mild form. The frequency of these symptoms after Covid-19 is difficult to assess; however, the rate appears to be higher in patients after hospitalization, due to the severity of the acute infection. Approximately 10% of patients appear to have persistent symptoms 3 months after Covid-19, including fatigue, dyspnea, chest pain, inadaptation to exercise, neurocognitive disorders and cardiovascular abnormalities. These prolonged symptoms after Covid-19 seem to persist beyond 3 months, and even 9 months in some cases, as in SARS. Their pathophysiology is not yet clear: understanding them will probably lead to better personalized management. In the meantime, the medical profession must be able to identify, evaluate and manage these prolonged symptoms with the available means (including re-education and rehabilitation), in the absence of specific treatment.