For some individuals, the road to recovery from COVID-19 is long. While most people recover from mild COVID-19 symptoms over the course of one to two weeks, “long-haul” patients can suffer from lingering symptoms for months on end. This syndrome, called post-acute COVID-19 or “long COVID,” can have devastating effects on the daily lives of millions of patients.
To discuss what we know about long COVID, Jodie Guest, PhD, professor and vice chair of the department of epidemiology at Emory’s Rollins School of Public Health, teamed up with Alex Truong, MD, co-director of the post-COVID clinic at Emory’s Executive Park. Truong is also an assistant professor in the Division of Pulmonary and Critical Care Medicine at Emory University School of Medicine.
Their conversation follows up on a previous discussion conducted in 2021 and is part of an online video series hosted by Guest, who leads the Emory COVID-19 Outbreak Response Team, answering questions related to the pandemic.
Q: What symptoms are associated with long COVID?
A: “A lot of our patients come in with very, very similar symptoms of brain fog, fatigue and shortness of breath,” says Truong. “It's almost as if I can cut and paste one patient’s story to the next patient.”
“It's very rare that someone comes in with a singular issue,” he continues. “It’s always a host of issues. Most of the time, patients are complaining that their brain fog and fatigue are the biggest limiters of their activities of daily living — their ability to get back to work, the ability to go back to school or take care of their kids. There's a smaller population of patients who have had chronic pain syndromes and chronic shortness of breath syndromes that are often very challenging to figure out.”
Q: How many people who have COVID-19 will develop long COVID?
A: “That's a really hard question to answer, because I think we are lacking the data,” Truong says. “I think, unfortunately, we aren't at a place yet where we really know who's at risk, and so we don't know what the proportions are.”
Guest notes that current estimates for the risk of long-term symptoms range broadly from 15% to 80% of COVID-19 patients.
“That span of statistics, being all over the board, includes patients who are severely sick in the hospital and those who are not severely sick,” Truong adds. “If I had to guess, I would have to say it's probably closer to the 15 to 20% range, depending on the population you’re looking at.”
Q: Is hospitalization due to severe COVID-19 associated with an increased risk of long COVID?
A: “A lot happens in the hospital and in the ICU that puts patients at risk for long-term outcomes, regardless of whether they have COVID or not,” Truong says, noting that survivors of any critical illness are prone to develop symptoms such as cognitive dysfunction, chronic fatigue and chronic pain.
“We have a syndrome called post-ICU syndrome that actually captures this collection of conditions that patients suffer from,” he says. “I think it's difficult to separate what is post-COVID syndrome versus what is post-ICU syndrome. As we move forward in this diagnosis, this category of post-COVID folks will have to be better defined so that we can better separate it from the post-ICU folks.”
One key difference Truong does see between the two syndromes is that post-acute COVID patients generally report issues with attention, concentration and brain fog, while individuals with post-ICU syndrome often experience more memory loss.
Q: Is long COVID associated with damage to cells in the body caused by COVID-19?
A: “Initially, we thought of COVID as a lung infection virus. We do see a lot of patients in our post-COVID populations who have persistent lung inflammation, and some patients progress to scarring, representing that there is direct lung parenchyma damage,” Truong says.
“We’re also realizing that COVID is possibly a vascular problem,” he continues. “It will affect the blood vessels and can cause a whole cohort of symptoms that may be explained by decreased blood flow, such as brain fog and some of the cardiomyopathies that we may be having.”
Some of these symptoms, such as lung and heart inflammation, may be reversed with medication. Unfortunately, symptoms like brain fog are more difficult to resolve.
“We're only at the very beginning steps of understanding how COVID affects the brain,” Truong says. “There are some data that suggest there are proinflammatory changes within the brain and movements of proinflammatory cells past the blood-brain barrier that may affect the limbic system, or the core systems of your brain that are responsible for things like mood, attention and memory.”
“We’re still in the process of trying to figure out what the importance of these different pathologies are,” he adds, noting that further research is needed to better understand these symptoms.
Q: Can people who fully recover from COVID-19 develop long COVID symptoms later?
A: “It was originally assumed that long COVID was associated with severe symptoms during your original infection, but now there seems to be some data that people are developing new issues after fully recovering from COVID-19,” Guest says. “Even people who didn't have symptoms can experience some of these post-COVID-related health issues, which can present as a lot of different types and combinations of health problems and seem to range for a long period of time.”
Truong says the causes of post-COVID syndrome among this category of seemingly recovered patients are particularly frustrating to trace.
“We do get a population of patients who have very mild symptoms or in some cases don't have any symptoms and just incidentally were found to have COVID, and then months later developed a syndrome of brain fog, fatigue and shortness of breath that isn't explained by some pathology and the lung,” he says.
“I think that initially, there was a lot of conversation as to whether inflammation was playing a role in why patients are having post-COVID syndrome,” he continues. “The thought was the more severely sick you initially were, the more likely you are to have post-COVID. That has totally been blown out of the water. We do not see that signal whatsoever.”
Truong adds that post-COVID symptoms among these patients may potentially be explained by preliminary research regarding COVID-19 and autoimmunity.
“Patients who get infected with COVID may recover from the initial illness easily, but subsequently develop some sort of auto-antibody or auto-protein that the body does react to, and then manifests a lot of these other symptoms,” he says.
Q: How do you know whether a patient has long COVID or another condition?
A: “That's been the big challenge in our clinic,” Truong says. “When patients come in with what sounds like post-COVID syndrome, the first step is always to make sure that there were confirmed COVID tests.” Patients can’t be diagnosed with post-COVID syndrome without having had a confirmed positive COVID-19 test.
Next, the clinic conducts several tests to rule out other diagnoses for patients who struggle with symptoms such as brain fog and fatigue.
“We do a whole slew of lab work that checks for thyroid levels, vitamin D deficiency, vitamin B12 deficiency, anemia and a bunch of other abnormalities,” he explains.
Easily treatable conditions like hypothyroidism and significant anemia are rarely diagnosed at the post-COVID clinic, and while vitamin deficiencies are common, Truong says patients often continue to experience symptoms even after those vitamins have been repleted.
“I think, unfortunately, we're at the stage where if you have a COVID diagnosis and I can't figure out other causes for your symptoms, then I'm blaming it on post-COVID syndrome,” he says. “That's not very sexy or scientific, but at this point in the evolution of this syndrome, this is where we're at.”
Q: When should people seek care for long-term symptoms after having COVID-19?
A: “I think that what patients should expect is that after their acute illness, in the next two to four weeks after they've been infected, they're not going to feel well,” Truong says. “They’re going feel like they have brain fog, they're probably going to have fevers and chills, body aches and fatigue.”
“If those symptoms last beyond four to six weeks from their initial infection and it's affecting their lives and the ways that they do their job, or affecting how they're functioning and activities of daily living, then I think that's when it's really important for them to come see us,” he continues.
“There is a population of patients who do have lingering symptoms past those four to six weeks after infection, and it's just getting better on its own, but slowly,” Truong adds. “To those patients, I would say, wait and watch. But if it's really affecting you, and it's not improving at all, then please don't wait too long to come see us.”
Q: Is the post-COVID clinic at Emory’s Executive Park still busy?
A: “Yes, we are very busy,” Truong says. “Interestingly, I was expecting a much bigger wave of new patients with the Omicron wave. I think that we're still seeing patients who were of the previous waves right now.”
“I feel like we're so much better at taking care of patients,” he adds, highlighting the progress the clinic has made since last year. “I think we have a little bit more data on our side, we have a lot more experience on our side, and I think we’re able to approach patients in a way that is much more systematic.”
Q: Where else can long COVID patients turn for support?
A: Many individuals with long COVID find support through social media. Online communities for people suffering from post-COVID symptoms have formed over platforms such as Facebook, Reddit and Twitter.
“There are several communities that actually have been really helpful,” Truong says. “Patients are passing information around, both for the good and bad. But I think right now, patients are finding the Internet is a really good resource for finding information on how to take care of themselves, as well as finding professionals who may be able to help them along with their journey.”
“That support system can be so good if the information is accurate,” Guest adds.
Q: Can children experience long COVID?
A: “Children can definitely get the long-haul or post-COVID syndrome. I think they tend to be less likely to have symptoms of shortness of breath and respiratory issues, and more likely to have a lot of the brain fog and fatigue issues that we're seeing,” Truong says.
While Truong only treats adult patients at the post-COVID clinic, he says he hears about teenagers who have experienced long-haul symptoms for more than a year after initial infection. “They can't get back to school and do the things that they need to do — most of which, again, centers around the brain fog and fatigue.”
Q: Does long COVID impact women more than men?
A: At the Emory post-COVID clinic, Truong sees about twice as many female patients as he does male patients.
“I think the data we have is that more women are showing up to the clinic than men are,” he says. “I have no idea whether that is because post-COVID syndrome is affecting women more than men, or if it is that they’re just seeking care and men are being stubborn and not seeking care.”
“I think in part it has to do with a selection bias, but I wouldn't be surprised if the rates are truly a little bit higher in women than men,” he adds. “In similar syndromes such as chronic fatigue syndrome, we do see that those rates are slightly higher in women than men.”
Q: Does vaccination impact the risk of developing long COVID?
A: “The data we have so far have suggested that yes, indeed, it is helping protect you from having post-COVID syndrome if you get a breakthrough infection after you've had all three of your shots, which includes the booster,” Truong says. “I do have a small population of patients who have had post-COVID syndrome after they've been vaccinated, but it seems like those folks tend to have rather mild disease and tend to resolve a lot faster than my folks who have not been vaccinated and got COVID, and thus post-COVID syndrome, after.”
“The safest way to keep from getting long COVID, or post-COVID syndrome, is certainly to make sure you keep from getting COVID-19,” Guest says. “The best way to do that is by getting vaccinated, getting a booster, making sure you protect those people who are around you, and when cases are still high out in the community, please wear a mask when you're indoors in public spaces.”