A meta-analysis of 12 studies shows that 30% of COVID-19 survivors have persistent symptoms 2 years after infection, the most common of which are fatigue, cognitive problems, and pain.
For the study, published yesterday in the Journal of Infection, an international team led by a researcher from Universidad Rey Juan Carlos in Madrid, Spain, searched the literature for observational and case-control studies of long COVID 2 years after infection. The studies, published up to October 1, 2023, were from Europe, China, and the United States.
The sample included 7,912 hospitalized and non-hospitalized COVID-19 survivors; the average age was 59.5 years, and 50.7% were women. Up to 54% of patients had at least one underlying medical condition, with high blood pressure (34.0%) and obesity (22.4%) the most common. Long-COVID symptoms were evaluated at an average follow-up of 723 days.
Psychologic problems also prevalent
The most common post-COVID symptoms 2 years post-infection were fatigue (28.0%), cognitive impairment (27.6%), and pain (8.4%). Psychologic problems such as anxiety (13.4%), depression (18.0%), and disturbed sleep (20.9%) were also prevalent.
The most common respiratory and general symptoms were fatigue (28.0%), runny nose (8.2%), and shortness of breath (5.7%). Prevalent neurologic and cognitive symptoms were dizziness and vertigo (6.7%) and impaired sense of smell (5.3%) and taste (4.9%).
This plethora of post-COVID symptoms can be explained by several mechanisms attributed to SARS-CoV-2 such as viral persistence, long-lasting inflammation, autoimmunity, reactivation of latent infections, alteration in gut microbiota, microvascular thrombosis, or others.
Stomach pain was the most common gastrointestinal symptom (6.7%); headache (8.9%) and muscle pain (8.1%) were the most prevalent pain symptoms; and hair loss was the most common dermatologic symptom (7.4%).
"This plethora of post-COVID symptoms can be explained by several mechanisms attributed to SARS-CoV-2 such as viral persistence, long-lasting inflammation, autoimmunity, reactivation of latent infections, alteration in gut microbiota, microvascular thrombosis, or others," the study authors wrote.
They added that population-based studies using homogeneous data-collection procedures are needed to further refine estimates of the prevalence of long COVID.