A large nationwide study has found important differences in the two main ways children have become seriously ill from the coronavirus, findings that can help doctors and parents better recognize conditions and understand more about children in risk of each.
The study, published Wednesday in the journal JAMA, analyzed 1,116 cases of young people who were treated at 66 hospitals in 31 states. Just over half of the patients had acute Covid-19, the predominantly lung-related disease that affects most adults who become ill from the virus, while 539 patients had the inflammatory syndrome that has flared in some children. weeks after having a typically mild illness. Initial infection.
The researchers found some similarities, but also significant differences in the symptoms and characteristics of the patients, who ranged from infants to 20 years old and were hospitalized last year between March 15 and October 31.
Young people with the syndrome, called Multisystemic Inflammatory Syndrome in Children or MIS-C, were more likely to be between 6 and 12 years of age, while more than 80 percent of patients with acute Covid-19 were younger than 6 years. or older. of 12.
More than two-thirds of the patients with any of these conditions were black or Hispanic, which experts say likely reflects socioeconomic and other factors that have disproportionately exposed some communities to the virus.
“It is still shocking that the vast majority of patients are not white and that is true for MIS-C and acute Covid,” said Dr. Jean A. Ballweg, medical director of pediatric heart transplantation and advanced heart failure at Children’s Hospital. & Medical Center in Omaha, which was not involved in the study. “There is a clear racial disparity there.”
For reasons that are unclear, although Hispanic youth appeared equally likely to be at risk for both conditions, black children appeared to be at higher risk of developing the inflammatory syndrome than the acute disease, said Dr. Adrienne Randolph, lead author. of the study and a pediatric intensive care specialist at Boston Children’s Hospital.
One potential clue mentioned by the authors is that with Kawasaki disease, a rare childhood inflammatory syndrome that bears similarities to some aspects of MIS-C, black children appear to have a higher frequency of heart abnormalities and are less responsive to one of the standard treatments: intravenous immunoglobulin.
The researchers found that young people with inflammatory syndrome were significantly more likely to have no underlying medical conditions than those with acute Covid. Still, more than a third of acute Covid patients had no prior medical conditions. “It’s not as if previously healthy kids are completely blameless here,” Dr. Randolph said.
The study evaluated obesity separately from other underlying health conditions and only in patients 2 years of age and older, and found that a somewhat higher percentage of young people with acute Covid were obese.
Dr. Srinivas Murthy, an associate professor of pediatrics at the University of British Columbia, who was not involved in the study, said he was not convinced that the findings established that healthy children were at increased risk for MIS-C. It could be “primarily a numbers game, with the proportion of infected children and the proportion of healthy children out there, rather than saying that there is something immune about healthy children that puts them at a disproportionately higher risk,” he said.
Overall, he said, the study’s documentation of the differences between the two conditions was helpful, especially since it reflected “a reasonably representative set of hospitals in the US.”
Young people with inflammatory syndrome were more likely to need treatment in intensive care units. His symptoms were much more likely to include gastrointestinal problems, inflammation, and affecting the skin and mucous membranes. They were also much more likely to have heart-related problems, although many of the acute Covid patients did not receive detailed cardiac evaluations, the study noted.
About the same large proportion of patients with each condition (more than half) required ventilation, and just under a third of those required mechanical ventilation. About the same small number of patients in each group died: 10 with MIS-C and eight with acute Covid-19.
The data does not reflect a recent spike in inflammatory syndrome cases that followed a spike in overall Covid-19 infections across the country during the winter holiday season. Some hospitals have reported that there have been a greater number of seriously ill MIS-C patients in the current wave compared to previous waves.
“I will be fascinated to see the comparison from November 1 onwards with this group because I think we all feel that children with MIS-C have been even sicker recently,” said Dr. Ballweg.
An optimistic sign from the study was that most of the serious heart problems in young people with inflammatory syndrome improved to a normal condition within 30 days. Still, Dr. Randolph said residual effects are still unknown, which is why one of her co-authors, Dr. Jane Newburger, associate chief for academic affairs in the department of cardiology at Boston Children’s Hospital, is leading a study. nationwide to follow children with inflammatory syndrome for up to five years.
“We cannot say 100 percent with certainty that everything is going to be normal in the long term,” said Dr. Randolph.