The sequelae of long COVID

The clinical symptoms of the acute phase of COVID-19 have been described in detail and involve pulmonary and extrapulmonary manifestations. However, cases of “long COVID” have also been reported, and some patients continue to suffer persistent symptoms over several months. Researchers at Saint-Louis, Missouri in the United States have listed the clinical symptoms that patients may experience for up to 6 months after their acute SARS-CoV-2 infection.

These researchers compared a cohort of 73 000 patients infected with SARS-CoV-2 to about 5 000 who were not infected. They were thus able to show that COVID-19 patients had a greater risk of death, a need for increased health care and could be affected by a number of sequelae after the 30 days of the illness’ acute phase. Amongst these patients, the researchers found:

• respiratory problems,
• diseases of the nervous system (neuro-cognitive problems or headaches, for example),
• mental health issues (sleep problems and anxiety),
• cardiac illness (hypertension, arrhythmia, bleeding disorders or cardiovascular arrest),
• digestive illness,
• other diverse symptoms were also reported, such as fatigue, musculoskeletal disorders or anaemia.

These sequelae may be due to diagnostic problems or to medication such as painkillers, antidepressants, anxiolytics or insulin. The researchers noted that the risk of sequelae is linked to the severity of the illness in its acute phase. They also observed that these sequelae were greater in patients with COVID-19 than those affected by seasonal flu.

The chronic clinical manifestations of patients infected with SARS-CoV-2 are still not fully understood. They may be the consequence of the viral infection, or of the over-activation of the immune system, but may also be due to poor diagnosis or to medication.