“That a mild SARS-CoV-2 infection can lead to new health problems three years down the road is a sobering finding,” an author of the study says.
Researchers tracking thousands of Covid-19 patients have uncovered some unnerving new data about the long-term effects of the disease.
According to a study released this week in Nature Medicine, patients who had been hospitalized when they contracted the virus still had an elevated risk of death three years later. Even people with mild cases were found to develop new health problems related to their infection far after their initial brush with coronavirus.
“I feel Covid-19 continues to teach us — and this is an important new lesson — that a brief, seemingly innocuous or benign encounter with the virus can still lead to health problems years later,” an author of the study, Ziyad Al-Aly, MD, said.
Here’s a closer look at this eye-opening research.
Long Covid and a higher risk of death
Researchers tracked 135,000 patients who had been diagnosed with Covid-19 early in the pandemic and compared their outcomes to another group of 5 million people who weren’t known to have had the virus. They found that people who had been hospitalized within 30 days of catching coronavirus had a 29 percent higher risk of death three years later. That’s not great, but it is significantly lower than one year after onset (182 percent) and at the two-year mark (57 percent).
Another metric researchers looked at was disability-adjusted life years (DALYs), which measures the years lost to poor health or premature death. Their research suggests that people hospitalized for Covid-19 had 90 DALYs per 1,000 people. That’s worse than the outlook for heart disease and cancer, which both have about 50 DALYs per 1,000 people.
For people who didn’t need a hospital stay for their symptoms, the team found 10 DALYs per 1,000 people and had a 5 percent increased risk of suffering from long Covid three years out. Dr. Al-Aly tells Fortune that among this group the primary complications they’re seeing are in the neurological, G.I., and pulmonary systems.
“That a mild SARS-CoV-2 infection can lead to new health problems three years down the road is a sobering finding,” Dr. Al-Aly, the director of the Clinical Epidemiology Center at the VA St. Louis Health Care System, says.
This is the largest study tracking the effects of Covid-19 over a full three-year period, although the authors acknowledged it does have several limitations. One is that the subjects were drawn from the Department of Veterans Affairs, meaning they’re “mostly older, white, and male,” the study says. The other is that the research began in 2020 before vaccines or antivirals were developed and because of that the infections are likely more severe; the research also doesn’t consider newer variants like omicron or the FLiRT strains.
Long Covid‘s other lingering effects
Experts are still trying to make sense of this condition, although according to data from the Centers for Disease Control and Prevention, 17 million Americans currently suffer from it.
Long Covid has been associated with more than 200 symptoms, from brain fog to extreme fatigue and debilitating issues like heart disease and stroke. For many, long Covid has been life-altering, which is why experts are still desperately seeking funding to develop new treatments and are urging the public to remain vigilant about the virus.
“Even three years out, you might have forgotten about Covid-19, but Covid hasn’t forgotten about you,” Dr. Al-Aly says. “People might think they’re out of the woods because they had the virus and did not experience health problems. But three years after infection, the virus could still be wreaking havoc and causing disease or illness in the guts, lungs, or brain.”
