This year, the world had to face the growing burden of long COVID. A tidal wave of people with lingering symptoms — some mild, some profoundly disabling — commanded attention.
“We are in the middle of a mass disabling event,” physician Talya Fleming of the JFK Johnson Rehabilitation Institute in Edison, N.J., told Science News (SN: 11/5/22, p. 22). A recent estimate suggests that over 18 million people in the United States have long COVID. Yet researchers know little about the disease and how to treat those who are suffering.
One key question is: Who is at risk? The search for risk factors has yielded few clear answers. Women may be slightly more likely than men to get long COVID, as are people who had more than five symptoms during their initial week of COVID-19 (SN: 10/8/22 & 10/22/22, p. 18).
Part of what confounds simple answers is that long COVID can hit multiple body systems, leading to fatigue, smell loss, memory trouble, blood clots and even sensations of internal tremors that feel like earthquakes (SN: 9/24/22, p. 14).
Symptoms could be due to persistent virus hiding out in the body, as well as the body’s responses to the intruder. Micro blood clots, antibodies that turn against the body, inflammation and even disturbances of helpful bacteria are all being scrutinized for their roles in the disease.
The lack of clarity is what makes finding treatments so hard. Doctors at long COVID clinics, which are few and far between, are scrambling to ease people’s symptoms, often borrowing therapies from other disorders that cause similar problems, such as myalgic encephalomyelitis/chronic fatigue syndrome (SN: 11/5/22, p. 25).
The long list of unanswered questions has taken on new urgency given the swell of people experiencing long COVID. Epidemiologist Priya Duggal of Johns Hopkins Bloomberg School of Public Health and colleagues suspect that between 10 and 30 percent of people who get COVID-19 may go on to get long COVID. That fits with federal data suggesting that about 30 percent of U.S. adults who have had COVID-19 have experienced long COVID. But surveys, medical records and other data all come with flaws, so exact numbers are impossible to come by, she says.
What’s perhaps most useful, Duggal says, is to consider how many people are severely constrained by their illness. “These are the people [who] were living happy, healthy lives and now they’re not,” she says. About 1 to 5 percent of people who had COVID-19 may fall into this category, she estimates. That sounds like a tiny number, she says, but “even if it’s 1 percent, it’s 1 percent of all people who have had COVID. And that’s just a really, really large number.” An estimated 100 million people in the United States have had COVID-19. That’s probably an undercount, Duggal says.
In the first days of the pandemic, Duggal and colleagues wanted to collect as much biological data on people as they could, before COVID-19 tore through the world. But logistics and a lack of funding prevented those baseline studies. “Had we had some of that in place, we could now be asking better questions and getting better answers,” she says. “I would hope that some of what this has taught us is that the next time this happens — and let’s hope it is no time soon — we have a bit more thought about what’s to come.”