Long COVID affects one in five people who contract the virus, CDC study shows

Twenty percent of people who get infected with coronavirus go on to develop serious chronic conditions that can permanently damage organs, even when that initial infection doesn’t result in symptoms or a trip to the hospital, according to a new, large study published by the Centers for Disease Control and Prevention.

Even though top New Mexico public health officials say chronic health problems caused by coronavirus are reason to avoid getting infected, they say they are not considering returning to public health policies that would slow transmission.

Long COVID is a chronic illness that leaves people living for months with a whole slew of symptoms, or even longer, well past their initial diagnosis or positive test result. Those symptoms can include life-changing effects on the heart, lungs, brain and blood vessels.

Even after an asymptomatic infection, one in five adults who test positive for the illness or who are diagnosed with it are likely to have one ongoing condition, according to the CDC study published in late May.

The likelihood is even higher for adults over 65. Among that population in the study, one in four developed long COVID.

For example, COVID survivors have twice the risk for developing a blood clot in the lung or other respiratory conditions, the study found.

The study builds on other research showing there are potentially tens of millions of people in the United States suffering from long COVID.

A different study looking only at Michigan found even higher rates of long COVID — one-third of people who catch the virus can endure lengthy effects, even when the initial symptoms seem “mild.”

COVID long-haulers in New Mexico have described experiences with the disease that are anything but mild, including fatigue, joint pain, cognitive decline and speech problems. And research shows that in the United States, Black, Hispanic and Indigenous people are far more likely to die from COVID than white people.

On June 13, the latest data available, New Mexico reported 6,357 cases for the week. That means there was a seven-day average of 908 new positive cases of COVID each day.

But the true count is much higher, in part because most testing is done at home and not reported to the state, according to DOH. That number is likely between three times and 10 times higher, according to acting Health Secretary David Scrase. 

So if one takes the findings in the CDC study and applies them to the current level of spread in New Mexico, there are between 544 and 1,816 people in New Mexico getting infected every day who will go on to develop Long COVID.

What is New Mexico doing about it?

Both Scrase and outgoing state epidemiologist Dr. Christine Ross said during a June 8 news conference that the danger posed by long COVID highlights the importance of not getting infected with coronavirus in the first place.

Long COVID is one of the reasons it is highly recommended to avoid getting infected in the first place, Ross said.

“But what we found is this variant is highly, highly transmissible, and it has become more difficult to avoid infection, especially now,” Ross said. “As we enter year three, we’re out living our lives, we’re moving around, we’re traveling, we’re gathering. So there’s lots of opportunity for exposure to the virus, and lots of opportunity to get infected.”

However, in the same news conference, Scrase dismissed the idea of re-implementing a statewide mask mandate to slow the spread of the virus as a matter of public policy.

This contradicts the recommendations in the new CDC study.

“Implementation of COVID-19 prevention strategies, as well as routine assessment for post-COVID conditions among persons who survive COVID-19, is critical to reducing the incidence and impact of post-COVID,” the researchers wrote, especially among those adults over 65.

They wrote that this need for more care can affect patients’ health care needs, economic well-being, their ability to contribute to the workforce, and have economic consequences for survivors and their dependents.

“In addition, care requirements might place a strain on health services after acute illness in communities that experience heavy COVID-19 case surges,” the researchers wrote.

Scrase said he has been talking with Alisha Parada, the chief of the general internal medicine division at the University of New Mexico, “about long COVID and how we can work more with UNM to have availability for COVID clinics.”

“That’s where we get our sense of urgency when we talk about vaccines, masks, because the best way to avoid long COVID is not getting COVID the first place,” Scrase said. “It’s going to be a big issue.”

What does long COVID look like?

A seven-person team of scientists at the CDC looked at health records created between March 2020 and November 2021 to see how often people developed any of a set of 26 different conditions often caused by COVID.

The study included 353,164 patients who received a COVID-19 diagnosis or a positive test result. It compared those people to 1.6 million control patients who visited health care facilities in the same month.

The findings are consistent with other large studies that show 20% to 30% of people develop long COVID after they first get infected, and that some need expanded follow-up care.

Other research seems to suggest that COVID long haulers have a reservoir of active virus in their bodies a full year after diagnosis.

As we learn more about long COVID and what we should do about it, we should be thinking about potential long-term conditions from the viral infection, said Elizabeth Jacobs, a professor of epidemiology at the Mel & Enid Zuckerman College of Public Health at the University of Arizona.

Jacobs doesn’t know the scope of long COVID yet, because it’s only been two years since the pandemic started. But the fact remains that masking lowers the rate of transmission, she said.

It’s scientifically impossible for us to know the long-term outcomes, but we have a great deal of evidence that at least in the short-term after infection, there are marked symptoms that can undercut participation in society, can be devastating for people who are still having symptoms six months after infection and can reduce productivity, she said.

While we do not know whether getting infected with coronavirus will create problems that crop up again in 20 years, Jacobs said, we have ample evidence of similar patterns with many other viruses, including Human Papillomavirus, Epstein-Barr virus, Hepatitis C and post-Polio syndrome.

“It would not surprise me if we saw that for COVID as well,” Jacobs said. “So it is to the benefit of all humans that we continue universal masking until we get a better handle on this.”