An analysis of 54 studies involving 1.2 million individuals from 22 countries who had Covid has revealed that 6.2 of them experienced at least one of the three long Covid symptoms -- persistent fatigue with bodily pain or mood swings, cognitive problems, or ongoing respiratory problems -- three months after acute infection onset.
Among individuals with long Covid symptoms three months after symptomatic SARS-CoV-2 infection, an estimated 15.1 per cent continued to experience symptoms at 12 months.
The risk of long Covid was greater in females and in those who needed hospitalisation for the initial SARS-CoV-2 infection, particularly among those needing intensive care unit care, according to the study published in JAMA Network.
The estimated proportion with at least one of the three self-reported long Covid symptom clusters included 3.7 per cent for ongoing respiratory problems, 3.2 per cent for persistent fatigue with bodily pain or mood swings, and 2.2 per cent for cognitive problems after adjusting for health status before Covid.
Of the 54 studies, 44 were published and 10 were collaborating cohorts (conducted in Austria, the Faroe Islands, Germany, Iran, Italy, the Netherlands, Russia, Sweden, Switzerland, and the US). Data collection spanned March 2020 to January 2022.
"Among individuals with long Covid symptoms three months after symptomatic SARS-CoV-2 infection, an estimated 15.1 per cent continued to experience symptoms at 12 months," the results showed.
Corresponding Author Theo Vos from Institute for Health Metrics and Evaluation, University of Washington, said that given that the longest follow-up among the included studies was 12 months, the true long-term pattern of symptom persistence for long Covid will only be revealed as studies conduct longer follow-up.
