Researchers hail it as an important step in understanding complications persisting after a COVID-19 infection, and they say it could lead to better treatments.
It’s been a long time coming.
Patients have suffered for months, even years, after being infected with COVID-19. Researchers have been struggling to unravel the mystery of what’s described as long covid, and there’s been some criticism about the lack of progress.
Now, after examining nearly 10,000 Americans, scientists say they have identified 12 distinct symptoms of long covid. The findings were published Thursday by JAMA. The National Institutes of Health supported the study.
The symptoms include fatigue after even relatively mild exertion, brain fog and chest pain, and other complications.
Leora Horwitz, an author of the study and director of the Center for Healthcare Innovation and Delivery Science at NYU Langone Health, said in a statement that the study “is an important step toward defining long COVID beyond any one individual symptom."
“This approach — which may evolve over time — will serve as a foundation for scientific discovery and treatment design,” Horwitz said.
About 15% of Americans report that they have had some symptoms of long covid, according to U.S. Census data. Worldwide, more than 658 million people have been infected with COVID-19, the study notes.
The 12 symptoms
Patients and researchers have found as many as 200 symptoms of long covid, the study notes. But researchers identified 12 symptoms that were most typical in separating those who have long covid and those who did not.
These are the 12 symptoms:
Post-exertional malaise, or worsening of symptoms after mild activity;
issues with sexual desire or capacity;
loss of smell or taste;
and abnormal movements.
About the study
The NIH’s Researching COVID to Enhance Recovery (RECOVER) initiative coordinated the research. Congress directed $1.15 billion for the RECOVER program, and the NIH is hoping to gain greater insights on treating and preventing long covid.
Researchers examined data from 9,764 adults, including 8,646 who had COVID-19 and 1,118 who did not have the virus.
Among 2,231 participants in the study who were first infected on or after Dec. 1, 2021, when the Omicron variant spread, 10% had symptoms of long covid six months later.
Researchers found that those who didn’t get the COVID-19 vaccine or who had COVID before the emergence of the Omicron variant in 2021 were more likely to have long covid, and their cases were more severe, the NIH said.
Those who had COVID-19 more than once were also more likely to have long covid and more severe complications.
Researchers developed a scoring system based on symptoms reported by patients. They gave each patient a score based on the combination of symptoms, and then established metrics for identifying those with long covid.
The authors said some symptoms routinely occurred together, so they established four clusters of common symptoms. In one cluster, for example, most experienced a combination of fatigue, malaise after exertion, dizziness, brain fog, GI issues and palpitations.
David C. Goff is the director of the division of cardiovascular sciences at the National Heart, Lung, and Blood Institute and serves as an epidemiology lead for the NIH RECOVER effort. He said the study provides an important tool in assessing patients, but it has its limitations.
“All patients suffering from long COVID deserve the attention and respect of the medical field, as well as care and treatment driven by their experiences,” Goff said in the statement. “As treatments are developed, it will be important to consider the complete symptom profile.”
Admiral Rachel Levine, the assistant U.S. health secretary, said in a statement that the RECOVER initiative “is making great strides toward improving our understanding of long COVID and its associated conditions.”
The authors of the new study said more research is needed on long covid and its relationship with age, race, gender, ethnicity, the social determinants of health, and pregnancy.
Seeking more progress
Some patient advocates have said they’ve been frustrated by the slow progress in studies of long COVID. Some have also bemoaned the lack of attention on COVID-19 more generally, especially now that the federal government has ended the COVID-19 Public Health Emergency.
In April 2022, U.S. Sens. Sheldon Whitehouse, D-R.I., and Ed Markey, D-Mass., wrote a letter to the NIH to express their dissatisfaction and urged the agency to pick up the pace on studies of long covid.
The senators said in the letter that they were concerned that the NIH has “prioritized long COVID observational studies over investigations of possible treatments and therapeutics to help those suffering from its symptoms.”
Dr. Clifford Rosen, who directs clinical and translational research at Tufts University, spoke with PBS NewsHour about the frustrations of patients with long covid. He has worked with long covid patients as part of the RECOVER initiative and told PBS that there’s a “huge disconnect between research and patient care.”
“We’re doing the research,” Rosen told PBS, “but you know what our people tell us? ‘Why aren’t you taking care of us?’”