New study identifies risk factors for severe COVID in kids

COLORADO SPRINGS, Colo. (KRDO) - A new study recently published in the Journal of American Medical Association (JAMA) has identified characteristics, outcomes, and severity risk factors associated with coronavirus infections in American children.

The study looked at data from the U.S. National COVID Cohort Collaborative, with 167, 262 children at 56 sites COVID positive and 10, 245 needing to be hospitalized.

The lead author on the study was a Colorado-based pediatrician: Dr. Blake Martin with CU School of Medicine on the University of Colorado Anschutz Medical Campus. KRDO spoke with Dr. Martin about the study's findings and what the research means for parents and doctors.

What are some of the risk factors you looked into for this study, and the major findings?

"We started off by looking at things that adults had demonstrated in terms of risk factors for more severe disease to see if they were replicated in kids," said Dr. Martin. "Overall, there are a lot of similar risk factors. Kids who got admitted into the hospital and who had a positive COVID test, those who ultimately went up to went on to develop severe disease, meaning they were in the ICU, needed to be on a ventilator, needed medications to support their heart function and the blood pressure. Those kids who developed severe disease were more likely to be male, they're more likely to be black or African-American, they're more likely to be obese, and they're more likely to have a bunch of different complex chronic medical conditions. What I mean by that is, children who have a prior history of cardiovascular disease, of cancer, of respiratory disease, those are the ones that were at highest risk of deteriorating during their hospitalization."

Did kids who developed severe COVID typically have all of those risk factors, a couple at one time, or only one?

"These are all independent risk factors," said Dr. Martin. "So a child who is male is at higher risk than a female, regardless of his race or obesity status. Certainly having many of these risk factors puts a child at higher risk, but each of them was an individual risk factor in and of itself."

Some of those risk factors were also found in the adult population. Was that to be expected?

"We thought that there would probably be some overlap between the two," said Dr. Martin. "In general, we saw that teenagers were a little bit more likely to develop severe disease compared to the younger kids, and so because it was kind of older children that are a little more similar to adults, I think it's not surprising that a lot of these risk factors were the same."

MIS-C was also looked into for this study, which a syndrome developed in some kids after they have COVID. Can you touch on those findings?

"MIS-C, which stands for 'multisystem inflammatory syndrome in children' is a condition of full body inflammation, which can affect the heart and the heart's blood vessels, and it usually occurs about 2 to 5 weeks after the initial COVID infection," said Dr. Martin. "What we found is that the kids who got an MIS-C diagnosis were actually more likely to be younger, and more likely to be otherwise healthy. So they didn't have many of these other complex medical history, complex medical conditions in their past."

When news about MIS-C was shared in 2020, it was kind of a 'mystery' illness with little answers as to why kids were coming down with it. Were you able to answer any of those questions with your research?

"This particular research study wasn't aimed at identifying the cause of it, and what's happening on the cellular level," said Dr. Martin. "A lot of good researchers are looking into that question, and thankfully, we have much better treatments now than we did at the beginning of the pandemic because we have a little bit better understanding of the physiology. But, I think this study is important because it will help a clinician in the hospital have a higher index of suspicion for when a child comes in to say, 'this child is more likely to develop severe disease from COVID-19 pneumonia, or this kid is actually at higher risk for developing MIS-C.'"

This data confirmed what a lot of people were already assuming: that most kids don't get severe COVID. Is that good news?

"I think it's an encouraging finding that in general, kids do very well," said Dr. Martin. "The overall mortality rate when you look at all of the 167,000 kids that tested positive in our study, was .08 percent. So we're talking like eight out of 10,000 kids who passed away during their hospitalization for SARS-CoV-2. That's great news. I think what the study adds is to tell clinicians, there are groups of children that are at higher risk for getting really sick if they get hospitalized with COVID. Again, these patients that are teenagers, black or African-American males with a complex past medical history, these are the kids that are kind of 'medically fragile' and more likely to develop severe disease. Our hope is that this can lead to systems of care in which these children are identified early, and that might be able to facilitate earlier and more aggressive treatment regimens and closer monitoring."

This study looked at kids who had a positive COVID test between March of 2020 and September of 2021. That time frame doesn't include the Omicron surge which sent adult and child case numbers soaring. How does that factor into your research?

"That's something we're working on now, is to see how is Omicron changing the picture? We had done a previous analysis looking at the difference between sort of the pre-Delta era and the Delta era. We didn't find a lot of differences in terms of which kids were getting sick. What we actually found is that while kids still got hospitalized at around the same rate - 6 percent of the patients in our cohort got hospitalized - that number was the same in the Delta era. Also in the Delta era, there were actually fewer kids who were needing these ICU type of therapies, so maybe actually less severity with Delta among kids than in the pre-Delta era. So it'll be interesting to see what comes out of Omicron. That's something that we're looking at right now is, how is it affecting pediatric outcomes? Are the risk factors the same? And one of the things I think will be really interesting to see is, is there a difference in the risk of MIS-C with the current variant compared to prior variants. Because most MIS-C cases lag the initial COVID infection by about a month, we're just starting to now see those changes, so stay tuned."

What would you say is the biggest takeaway from this research?

"I think the biggest takeaway is that while children do very well with SARS-CoV-2 infections, there is definitely a group of medically fragile children that are at much higher risk for severe disease and ending up in the ICU," said Dr. Martin. "So everything we can do to prevent one of those children from getting infected is a big win. Whether that's getting yourself vaccinated, getting your eligible children vaccinated, those are the things that we can do to prevent these poor outcomes among these medically fragile children."