When Jaime Seltzer first heard about a new virus that was spreading globally early in 2020, she was on full alert. As an advocate for the post-viral condition known as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), she worried about a new wave of people having long-term disabilities.
“The hair on my arms stood on end,” said Ms. Seltzer, director of scientific and medical outreach at the advocacy group MEAction and a consultant researcher at Stanford University.
Ms. Seltzer, who has had ME/CFS herself, said she wondered.
Sure enough, later in 2020, reports began emerging about people with extreme fatigue, postexertion crashes, brain fog, unrefreshing sleep, and dizziness when standing up months after a bout with the then-new viral illness. Those same symptoms had been designated as “core criteria” of ME/CFS by the National Academy of Medicine in a 2015 report.
Now, advocates like Ms. Seltzer are hoping the research and medical communities will give ME/CFS and other postviral illnesses the same attention they have increasingly focused on long COVID.
The emergence of long COVID was no surprise to researchers who study ME/CFS, because the same set of symptoms has arisen after many other viruses.
“This for all the world looks like ME/CFS. We think they are frighteningly similar, if not identical,” said David M. Systrom, MD, a pulmonary and critical care medicine specialist at Brigham and Women’s Hospital in Boston, who studies people with both diagnoses.
The actual numbers are hard to determine, since many people who meet ME/CFS criteria aren’t formally diagnosed. But a combined analysis of data from several studies published in March found that about one in three people had fatigue and about one in five reported having a hard time with thinking and memory 12 or more weeks after they had COVID-19.
According to some estimates, about half of people with long COVID will meet the criteria for ME/CFS, whether they’re given that specific diagnosis or not.
Other conditions that often exist with ME/CFS are also being seen in people with long COVID, including postural orthostatic tachycardia syndrome, which causes people to feel dizzy when they stand, along with other symptoms; other problems with the autonomic nervous system, which controls body systems such as heart rate, blood pressure, and digestion, known together as dysautonomia; and a condition related to allergies called mast cell activation disorder.
Post–acute infection syndromes have been linked to a long list of viruses, including Ebola, the 2003-2004 SARS virus, and Epstein-Barr – the virus most commonly associated with ME/CFS.
The problem in clinical medicine is that once an infection has cleared, the teaching has been that the person should no longer feel sick, said Nancy G. Klimas, MD, director of the Institute for Neuro-Immune Medicine at Nova Southeastern University in Miami. “I was taught that there has to be an antigen [such as a viral protein] in the system to drive the immune system to make it create sickness, and the immune system should shut off when it’s done,” she said.
Thus, if virus is gone and other routine lab tests come up negative, doctors often deem the person’s reported symptoms to be psychological, which can upset patients, Anthony Komaroff, MD, of Brigham and Women’s Hospital in Boston, wrote in July 2021.
Only recently have doctors started to appreciate the idea that the immune system may be overreacting long term, Dr. Klimas said.
Now, long COVID appears to be speeding up that recognition. Dr. Systrom said he has “absolutely” seen a change in attitude among fellow doctors who had been skeptical of ME/CFS as a “real” illness because there’s no test for it.
“I’m very keenly aware of a large group of health care professionals who really had not bought into the concept of ME/CFS as a real disease who have had an epiphany of sorts with long COVID and now, in a backwards way, have applied that same thinking to their very same patients with ME/CFS,” he said.