Public health experts are divided on how many people live with COVID-19, a potentially debilitating condition that develops after a patient has recovered from the coronavirus.
Adverse effects of the condition can include fatigue, pain, neurological problems, and even mental health changes.
Initially, public health officials believed that only a small minority of people would suffer from COVID-19 on a long-term basis. But some studies now indicate that a majority of those infected with the coronavirus experience long-lasting COVID-19 symptoms.
Still, estimates of the number of people with long-term COVID are all over the map.
Researchers at the Penn State College of Medicine found that more than half of COVID-19 survivors had long-term COVID-19.
Another study from the University of Arizona found that about 2 in 3 people who had mild or moderate cases of coronavirus had long-lasting symptoms.
Other reports have been more conservative, estimating that anywhere from 10 to 30 percent of those infected develop long-term symptoms. Those who experience persistent symptoms of long-term COVID-19 are sometimes known as COVID-19 lung transporters.
It is generally believed that people who have developed severe cases of COVID-19 are more likely to have long-term COVID-19, but even those who had asymptomatic cases have reported lingering after-effects months after a negative test.
One problem in figuring out how many people live to be COVID-19 is defining it.
Aside from the wide range of symptoms, there is still debate about when a person is considered to have long-term COVID-19. Some health authorities believe a patient has the condition if symptoms persist beyond three to six weeks, while others believe it should be considered on a longer-term basis.
Jim Heath, president and professor at the Institute for Systems Biology, leads the Pacific Northwest consortium investigating long-term COVID-19 as part of the National Institute of Health’s (NIH) RECOVER initiative, which is investigating the post -COVID-19 condition and possible ways to prevent and treat it.
Heath told The Hill that if one definition of long-term COVID-19 were used — a definition in which symptoms persisted for about four to six weeks after infection — about half of those infected would be considered long-term COVID-19.
“But if you look at six months out, which is for people who are really going to have to live with something, it’s probably more like 15 percent, something like that. I don’t know if we have any real hard numbers on that yet,” Heath said.
According to Heath, an estimate of 15 to 20 percent of coronavirus survivors who had long-term COVID-19 after six months was a reasonable “educated guess” and he added that there was evidence to support that percentage.
When asked for comment on The Hill, the NIH said preliminary studies showed that at least half of COVID-19 patients hospitalized reported “persistent weakness or fatigue” months into their recovery.
Studies on the prevalence of long-term COVID-19 have been “relatively few,” according to the NIH, and all have focused on people with symptomatic cases of COVID-19.
Heath reiterated that most people won’t get COVID-19 for long, at least if you think of the condition as lasting six months after infection. By comparison, about 15 percent of people who contract Lyme disease, a bacterial infection spread through ticks, experience effects that last longer than six months.
What long makes COVID-19 unique is its occurrence in those with mild cases, Heath said.
The NIH said numerous observational studies are being conducted in both children and adults to find potential treatments for long-distance runners. The agency has filed applications for new clinical trials to launch this summer to test potential ways to prevent and treat long-term COVID-19.
“Contrary to the wealth of prior knowledge that led to the vaccines for Sars-CoV-2 and numerous other viruses, much less is known about what causes persistent symptoms after infectious diseases or how best to treat them. As a result, more knowledge is needed to fuel upcoming scientific advances,” the NIH said.