Long-suffering SARS patients offer clues about the worrisome futures that may await COVID-19 long-haulers

• Studies of SARS patients have shown that many suffered from symptoms resembling chronic fatigue syndrome years after their infections.
• Doctors are drawing a similar link between chronic fatigue and lingering COVID-19 symptoms.
• It's unclear how long these symptoms will last, since research into SARS diminished before treatments were developed.
• A SARS researcher thinks some people with long-lasting COVID-19 symptoms may never be able to return to work.

The clues were there all along. In the years following the 2003 SARS outbreak, studies showed many patients hadn't recovered six months to a year after their symptoms started. Some suffered from persistent muscle weakness and impaired lung function.

A 2011 study of 109 SARS patients in Toronto found that more than half hadn't returned to work a year after they were discharged from the ICU. And 2009 research in Hong Kong found that more than 40% of SARS patients studied there reported chronic fatigue four years after their illness began.

Similarly, many COVID-19 patients have reported that symptoms can last several months. In July, Business Insider spoke to 17 coronavirus patients who had symptoms for more than 100 days. Italian researchers also recently evaluated 179 patients roughly two months after their first COVID-19 symptoms and found that around 44% had a diminished quality of life. Many were still suffering from fatigue, shortness of breath, body aches, and chest pain.

The new coronavirus is genetically similar to SARS: The two share about 80% of their genetic code, and both belong to the coronavirus family, which includes hundreds of viruses that mostly circulate among animals. But SARS and the novel coronavirus, clinically known as SARS-CoV-2, are two of just three coronaviruses that can prove fatal in humans.

So past research into SARS patients offers critical clues about the future of COVID-19 long-haulers.

"One can anticipate — and this is a prediction — that a significant proportion of the population who were employed when they became ill with [COVID-19] may not be able to return to work in any meaningful way," Dr. Harvey Moldofsky, a professor emeritus who studied SARS patients at the University of Toronto, told Business Insider.

But what will be crucial this time, Moldofsky added, is that funding continue for long-term follow-up research — unlike what happened when he sought to keep studying SARS.

SARS offered early evidence of lingering symptoms

The SARS outbreak was deemed contained in July 2003, less than four months after it was identified by the World Health Organization. By then, there had been roughly 8,100 infections and 774 deaths reported worldwide. The outbreak was mostly limited to China.

About four years later, Moldofsky began tracking a small group of healthcare workers who'd been previously infected with SARS in Toronto. At the time, he said, there was "zero interest" in SARS research, so Moldofsky carried out his study without any grant funding.

"Nobody wanted to touch it because there was no incentive to get involved in a disease that disappeared," Amesh Adalja, a senior scholar at the Johns Hopkins University Center for Health Security, told Business Insider. "If we would have had a countermeasure against SARS in 2003, we would have been in a much better place."

After studying the healthcare workers for an average of two years, Moldofsky found similarities between the SARS patients and people with chronic fatigue syndrome. Some of the healthcare workers, he added, wound up in and out of the hospital for years.

"They recovered from the acute illness, but they still had lingering symptoms," Moldofsky said.

His research also identified a bundle of symptoms — persistent fatigue, muscle pain, weakness, and non-restorative sleep — that were unique to SARS patients. He labeled the condition "chronic post-SARS syndrome."

"We showed that these were a distinct group of people, similar to the fibromyalgia [patients], but without as much pain," he said.

But after Moldofsky's paper was published in 2011, it fell into "relative obscurity" along with the rest of SARS research, he said.

Still, Moldofsky was convinced that his findings had important implications for future epidemics. He was right.

Researchers are now zeroing in on a diagnosis for patients recovering from COVID-19 that's similar to the condition Moldofsky defined for SARS patients.

"As happened after the SARS outbreak, a proportion of COVID-19 affected patients may go on to develop a severe post viral syndrome we term 'Post COVID-19 Syndrome,'" researchers at Manchester University wrote in June. They defined the condition as "a long term state of chronic fatigue" in which people experienced additional pain or brain fog after increased physical activity.

Data on COVID-19 recoveries is limited

Nearly 22 million people have been infected with the coronavirus worldwide, and more than 776,000 have died. About 13.7 million are counted as "recovered," but in many cases, that classification simply means someone has left the hospital.

"These numbers don't really characterize what's going on," Moldofsky said, adding that the word "recovered" is "a vague term."

At the start of the pandemic, the Centers for Disease Control and Prevention suggested that mild coronavirus symptoms typically lasted for 14 days, while the World Health Organization reported that recovery could last up to six weeks for severe or critical patients. More recently, both agencies have acknowledged that the coronavirus may have longer-term symptoms, but neither has offered a timeline.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said in July that it may take "months to a year or more to determine if there are any long-lasting, deleterious consequences of the infection."

That uncertainty means patients already struggling with long-lasting consequences of COVID-19 don't get clear answers from their doctors.

"We're all kind of diagnosing each other," Peggy Goroly, a 56-year-old from Long Island who belongs to a coronavirus support group on Facebook, told Business Insider. "You'll hear someone else say something and then you realize it's happening to you, too."

Goroly has been sick since March 5, with symptoms including fatigue, brain fog, heart palpitations, and shortness of breath. Others in online support groups say they've been in and out of the emergency room. Some face unemployment, are considering filing for disability, or struggle to care for their children or family members.

"Unfortunately, there will be a small subset of people for whom that becomes the case and these symptoms really do become a chronic thing that you're dealing with for years," Dr. Nate Favini, the medical lead at Forward, a primary-care practice that's collecting data on coronavirus patients around the country, told Business Insider.

Parallels to chronic fatigue syndrome

A growing chorus of doctors, including Fauci, have likened long-lasting coronavirus symptoms to chronic fatigue syndrome, which is often characterized by cognitive impairment, muscle pain, and a debilitating lack of energy.

"There's talk in the the medical community about a chronic fatigue syndrome-like illness that could happen after coronavirus," Favini said.

Simon Wessely, former president of the Royal College of Psychiatrists, told New Scientist in April that he predicted the pandemic would lead to "many, many cases of post-infective fatigue syndrome."

The 2009 Hong Kong study found similar long-term trends among SARS patients: Among a group of 233 patients, 27% met the CDC's clinical criteria for chronic fatigue syndrome.

There are several possible reasons for these long-term health problems among coronavirus patients. In some cases, patients may develop blood clots that contribute to feelings of fatigue.

"If people have a bunch of small clots in their lungs, that can continue to cause fatigue for a long period of time — even after the clots are gone — if there's damage to the blood vessels," Favini said.

An aggressive immune response to the virus could also trigger inflammation in the body that damages healthy tissue.

"You have to separate the damage from the disease," Dr. Ramzi Asfour, an infectious-disease doctor in Marin County, California, previously told Business Insider. "The symptoms are probably coming from an immune reaction."

Either of these responses could impair the nervous system, resulting in depleted energy, muscle weakness, or trouble concentrating or sleeping.

In his 2011 study of SARS patients, Moldofsky found evidence that the virus had crossed the patients' blood-brain barriers, leading to long-lasting neurological problems that disrupted their sleep and cognition. He thinks the new coronavirus likely operates in a similar manner.

"It's an inflammatory disease that is interfering with the conduction of the normal pathways of the nervous system," Moldofsky said.

Some symptoms are still baffling to doctors

A major challenge in studying the effects of COVID-19 — in addition to the lack of long-term data — is that patients who feel sick can appear healthy on paper.

"If you look at my test results, I look healthy as a horse, but my symptoms aren't matching the test results," Cheyenne Beyer, a 27-year-old coronavirus patient in Austin, Texas, previously told Business Insider. "Pretty much every doctor I've run across has tried to pin it on anxiety first."

Moldofsky said the current refrain among physicians is similar to the one he heard in 2011: "We don't know what to do with our patients. They're complaining they're sick, but they're not sick. We can't find anything wrong with them."

Doctors were similarly confounded by lingering, mysterious ailments among SARS patients, he added, since their MRIs didn't show obvious damage to the nervous systems.

"They had no idea why they were like this," Moldofsky said. "No one could give them any explanation."

The patients also didn't respond to treatment.

"They tried everything," Moldofsky said. "They tried physiotherapy, occupational therapy. They had psychologists try to treat them, and they weren't getting anywhere."

Moldofsky added that he's heard anecdotally about healthcare workers he studied in 2011 who still aren't better.

"This is going on years now that they're afflicted with this and they could not return to their duties," he said.

But he never got funding for a follow-up study.

Doctors are starting to look for answers

As more coronavirus patients struggle with the long-term aftermath of their infections, scientists have begun to investigate the drivers of these lasting symptoms. Researchers at King's College London are examining whether certain genetic or environmental factors might lead to post-COVID syndrome. In May, a coalition of scientists at the Open Medicine Foundation embarked on a multi-year study to see whether COVID-19 triggers chronic fatigue syndrome.

Rep. Jamie Raskin, a Democrat from Maryland, has also co-sponsored a bill in Congress that calls for $15 million in annual funding through 2024 to support research into COVID-related cases of chronic fatigue.

But Moldofsky said many doctors may still find themselves at a loss for how to help patients right now.

"Epidemiologists are always looking for short, quick, yes-no responses because you're sampling hundreds of thousands of people," he said. "Well, the symptoms are not objective. They're subjective."

Even so, he hopes the scale of this pandemic will ensure that potential treatments for post-COVID syndrome get funding.

"When we better understand what this disease is all about — how it affects the organs of the body, how it affects the brain, the heart, the kidneys, the liver — then specific remedies may become available," Moldofsky said. "It's a hope, and I'm optimistic that such will be the case."