Nearly a third of people with COVID-19 experience persistent symptoms for up to nine months after diagnosis, even if they initially have a mild case, a small new study suggests.
Researchers at the University of Washington study analyzed information from 177 people in the Seattle area with confirmed COVID-19 infections who were followed up for three to nine months after diagnosis. (The average follow-up time was six months.) Most participants – 150 people, or 85% of the study group – had a mild case of COVID-19 and were not hospitalized; 11 participants (6%) were asymptomatic; and 16 participants (9%) were hospitalized.
Overall, 32.7% of patients with mild cases and 31.3% of hospitalized patients reported having at least one persistent symptom that lasted at least three months after diagnosis.
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The most common persistent symptoms were fatigue, reported by 13.6% of participants in general, and loss of smell or taste, also reported by 13.6% of participants, the authors said. About 13% of participants experienced other persistent symptoms, including muscle pain, difficulty breathing, coughing and brain fog.
“Our research indicates that the health consequences of COVID-19 go far beyond acute infection, even among those with mild illnesses,” wrote the authors in their article, published on Friday (February 19) in the newspaper Open JAMA network.
The authors also asked participants about their quality of life after being infected, and 30% of participants reported worse quality of life compared to before infection, including 8% who reported problems with daily tasks, such as household chores.
“What is clear is that you can do well at first, but then, over time, you develop symptoms that are quite disabling in terms of fatigue,” said the study’s senior author, Dr. Helen Chu, associate professor of medicine at Division of Allergy and Infectious Diseases, University of Washington School of Medicine, said in a statement.
The study is one of the longest follow-ups of people with COVID-19. However, the study was limited because it included a relatively small number of participants from a single location. Still, with millions of cases worldwide, “even a small incidence of long-term weakness can have huge economic and health consequences,” wrote the authors.
Exactly why some people develop these persistent symptoms – sometimes called “COVID long“- it is not clear.” It’s some kind of immune activation, some kind of inflammation or the development of autoimmunity? asked Chu, who added in the statement that she and her colleagues will analyze blood samples from patients with COVID-19 to study this issue.
Originally published on Live Science.