Even mild COVID-19 cases can have major and long-lasting effects on people’s health. That is one of the key findings from our recent multicountry study on long COVID-19 – or long COVID – recently published in the Journal of the American Medical Association.
Long COVID is defined as the continuation or development of symptoms three months after the initial infection from SARS-CoV-2, the virus that causes COVID-19. These symptoms last for at least two months after onset with no other explanation. We found that a staggering 90% of people living with long COVID initially experienced only mild illness with COVID-19. After developing long COVID, however, the typical person experienced symptoms including fatigue, shortness of breath and cognitive problems such as brain fog – or a combination of these – that affected daily functioning.
These symptoms had an impact on health as severe as the long-term effects of traumatic brain injury. Our study also found that women have twice the risk of men and four times the risk of children for developing long COVID. We analyzed data from 54 studies reporting on over 1 million people from 22 countries who had experienced symptoms of COVID-19. We counted how many people with COVID-19 developed clusters of new long-COVID symptoms and determined how their risk of developing the disease varied based on their age, sex and whether they were hospitalized for COVID-19.