WASHINGTON (AP) — According to a survey of nearly 10,000 Americans that aims to help unravel the mysterious condition, about 10% of people appear to have long-term COVID after an omicron infection, a lower estimate than earlier in the pandemic.
Early findings from the National Institutes of Health study highlight a dozen symptoms most characteristic of long COVID, the umbrella term for the sometimes debilitating health problems that can persist for months or years even after a mild case of COVID-19.
Millions of people around the world have long had COVID, with dozens of widely varying symptoms, including fatigue and brain fog. Scientists still don’t know what causes it, why it only affects some people, how to treat it — or even how best to diagnose it. Better defining the condition is essential for research to get those answers.
“Sometimes I hear people say, ‘Oh, everyone’s a little tired,'” said Dr. Leora Horwitz of NYU Langone Health, one of the study’s authors. “No, there’s something different about people who have had COVID for a long time and that’s important to know.”
The new research, published Thursday in the Journal of the American Medical Association, includes more than 8,600 adults who had COVID-19 at various points in the pandemic, compared to another 1,100 who were not infected.
By some estimates, about 1 in 3 of COVID-19 patients have experienced long-term COVID. That compares to the NIH study participants who reported being sick before the omicron variant started spreading in the US in December 2021. That’s also when the study kicked off, and researchers noted that people who already had long-term COVID symptoms were more likely to enroll.
But about 2,230 patients had their first coronavirus infection after the study started, which allowed them to report symptoms in real time — and only about 10% experienced long-term symptoms after six months.
Previous research has suggested that the risk of long-term COVID has decreased since the appearance of omicron; his descendants are still spreading.
The bigger question is how to identify and help those who have had COVID for a long time.
The new study focused on a dozen symptoms that may help define long-term COVID: fatigue; brain fog; dizziness; gastrointestinal symptoms; palpitations; sexual problems; loss of smell or taste; thirst; chronic cough; chestpain; worsening of symptoms after activity and abnormal movements.
The researchers scored the symptoms, trying to establish a threshold that could ultimately help enroll similar patients in trials of potential long-term COVID treatments, as part of the NIH trial or elsewhere, for comparison of apples with apples.
Horwitz stressed that doctors shouldn’t use that list to diagnose someone with long-term COVID — it’s just a potential research tool. Patients can have any of those symptoms, or many — or other symptoms not on the list — and still experience long-term effects from the coronavirus.
Everyone is researching long COVID, but “we don’t even know what that means,” Horwitz said.