Researchers looking for long COVID symptoms find only 7

The Centers for Disease Control and Prevention’s tally of 19 possible long COVID symptoms comes with the caveat that it's “not a comprehensive list.”

Yale Medicine counts 22 symptoms, while the Mayo Clinic lists 10. And Great Britain’s National Health Service (NHS) puts the number at 16.

These lists can be made even longer. For instance, the NHS has “high temperature, cough, headaches, sore throat and changes to sense of smell or taste” as one symptom. Mayo lists “difficulty thinking or concentrating, headache, sleep problems, dizziness when you stand, pins-and-needles feeling, loss of smell or taste and depression or anxiety” as one symptom.

A major obstacle to helping patients with long COVID is that currently there are no generally agreed-upon diagnostic or treatment guidelines. Narrowing down exactly what symptoms point to long COVID would be a start, and researchers at the University of Missouri (MU) think they’ve done just that by slimming the field of long COVID symptoms down to just seven: fast-beating heart, hair loss, fatigue, chest pain, shortness of breath, joint pain and obesity.

Their study in Open Forum Infectious Diseases said that “understanding the population and subgroup risks for long COVID associated with outcomes, including lingering and chronic never-before-experienced symptoms and new medical diagnoses such as those reported here, is important for clinicians and researchers so that clinical guidelines for treatments and symptom management can be more appropriately developed for the growing number of adults affected by COVID-19.”

Chi-Ren Shyu, Ph.D., the director of the MU Institute for Data Science and Informatics and the corresponding author of the study, tells Fierce Healthcare that “understanding the population and subgroup risks for long COVID associated with outcomes, including lingering and chronic never-before-experienced symptoms and new medical diagnoses such as those reported here, is important for clinicians and researchers, so that clinical guidelines for treatments and symptom management can be more appropriately developed for the growing number of adults affected by COVID-19.”

Shyu and co-authors examined data from 52,461 patients collected in electronic health records at 122 healthcare facilities across the U.S. They identified 47 possible symptoms of long COVID. They compared symptoms in three groups:

  • Individuals who had COVID-19 but didn’t have common viral problems associated with the disease such as influenza or pneumonia.
  • Individuals who didn’t have COVID-19 but did have a different viral respiratory infection.
  • Individuals who had neither COVID-19 nor one of the other infections.

“Previous work has briefly investigated the differences in outcomes between hospitalized COVID-19 and influenza patients,” the study states. “Our work provides additional information on this subject by analyzing a larger and more diverse patient cohort, including other common viral respiratory infections, and examining outcomes in patient cohorts not limited to patients hospitalized for the initial infection.”

The authors said they hope their findings will point out what symptoms clinicians should look for when trying to determine whether somebody has long COVID. “A better recognition of post COVID syndrome or long COVID will help us study the underlying reasons that cause these prolonged abnormalities and also help us develop screening protocols to be used when COVID-19 survivors are seen within the healthcare systems,” says Shyu. “Such recognition also helps in developing focused treatments and rehabilitation strategies to promote recovery.”

Adnan Qureshi, Ph.D., a professor of neurology at the MU School of Medicine and co-author of the study, notes in a press release that the “survivors still have symptoms that are at times disabling and preventing them from going back to work or the activities of their daily life. This is not because the COVID-19 infection is still active, but instead, the infection has caused long-term consequences, or sequelae, in the form of a post-COVID syndrome that could persist for months or even years. Our research was able to identify long-term sequelae that are distinctive to COVID-19 and separate the post-COVID syndrome from other post-viral syndromes.”

One symptom of long COVID that their study found bolsters the findings of previous studies that linked the condition to heart problems.

“The virus directly and at times the inflammatory reaction secondary to virus effects the heart muscles resulting in prolonged cardiac issues,” says Shyu. “There is inflammation seen in heart muscles both in the early and late period after virus infection. There is also clot formation in the blood vessels of the heart resulting in loss of blood flow to the heart causing heart attack. Even when these processes subside, there is scarring within the heart.”