There were 24 deaths recorded, across all age groups. In the study, there was no information on whether the patients had underlying illnesses, but the doctors and researchers reported that young people with MIS-C were generally healthy before and were much more likely to be healthy than the relatively small number of young people. who suffered from serious illnesses due to initial covidial infections.
Of the 1,075 patients for whom information about initial Covid disease was available, only 265 showed symptoms at this point. They were more likely to be older: their mean age was 11 years, while the mean age of patients with asymptomatic covid infections was 8 years. However, this could be because “younger children cannot express their concerns with the same efficiency,” said Blumenthal. who co-wrote an editorial about the study.
“In reality, we don’t know if there are actually fewer symptoms in the very young population,” he concluded.
It is also unclear why the study found that young people were more prone to some of the most serious cardiac complications in the first MIS-C wave from March 1 to July 1, 2020. DeBiasi said this was inconsistent with the experience at his hospital where “the children in the second wave were sick”.
The study documented two waves of MIS-C cases that followed an increase in total coronavirus cases for a month or more. “The third-to-last surge in the COVID-19 pandemic appears to be leading to yet another MIS-C surge that can involve both urban and rural communities,” the authors wrote.
The study found that most of the states with the highest MIS-C case rate per population were in the Northeast, where the first increase in cases occurred, and in the South. In contrast, most states with high rates of children with COVID-19 by population but low rates of MIS-C were in the Midwest and West. Although the concentration of cases spread from large cities to small towns over time, it was not as pronounced as the general trends in the pandemic, the authors said.
Blumenthal said the geographic pattern might reflect that “understanding of disease complications” was not widespread in all regions, or that many states with lower MIS-C rates have less ethnically diverse populations. “It could also have something to do with the Covid itself, although we don’t know,” he said. “At the moment we don’t know how the variants necessarily affect children.”
The study set only the strictest criteria for MIS-C, with the exception of approximately 350 reported cases that met the CDC definition of the syndrome but had a negative antibody test or had primarily respiratory symptoms. DeBiasi said there are also many likely cases of MIS-C that are not reported to the CDC because they do not meet all of the official criteria.