Deadly Covid-Linked Syndrome May Be Undercounted in U.S. Kids

Over the course of the pandemic, Texas Children’s Hospital has cared for more than 150 young patients with a rare and sometimes deadly inflammatory condition linked to Covid-19.

The Houston institution is one of more than a dozen children’s hospitals in the state. Yet for all of Texas, the U.S. Centers for Disease Control and Prevention has tallied fewer than 100 cases of children with the condition, called multisystem inflammatory syndrome in children, or MIS-C.

“If our hospital has seen well over 150, then clearly that number is not accurate,” said Lara Shekerdemian, chief of critical care at Texas Children’s. About three-quarters of the kids who suffer from it in her hospital wind up in intensive care, she said.

Covid-19 cases overall are going down in the U.S., according to the CDC, but data on the life-threatening inflammatory response are less clear cut. The numbers are updated monthly and even then there is a significant lag. The CDC says 3,742 children have been diagnosed with MIS-C in the U.S. since early in the pandemic. That number is likely low — the agency says it’s not performing a comprehensive count.

That’s disquieting news for parents of unvaccinated children under 12 or for those of adolescents who have yet to get their shots. Most MIS-C cases have shown up in children from 5 to 14, with a median age of 9, according to the CDC.

The data lag is caused by a voluntary reporting system that relies on overburdened hospitals and state health departments, which sometimes report cases late or not at all. Doctors and health officials also need time to determine whether a child truly meets the complicated definition of a MIS-C diagnosis.

While some health departments have reported totals that appear in line with the CDC’s data, large states such as New York, California and Texas show discrepancies.

New York’s Department of Health says it’s investigating 498 reported cases of MIS-C. Yet the CDC reports New York has had only between 100 and 149 cases since reporting began last year.

California’s numbers are especially obscure, because the CDC lists the state only as having more than 300 MIS-C cases. Los Angeles County’s health department alone has reported 186 children with MIS-C.

The CDC doesn’t view the data on its website as a complete tally, said spokeswoman Jade Fulce. Instead, the agency uses it to understand trends.

MIS-C started as mystery, afflicting children who were otherwise healthy. Early in the pandemic, doctors assumed it was Kawasaki disease, which causes inflammation in blood vessels. They soon determined the children showing up in emergency rooms with swollen hands, bloodshot eyes and blue lips also had fairly recent Covid-19 infections.

MIS-C has dramatic and frightening symptoms. Then it gets worse. Children often go downhill rapidly as the body’s attempt to fight off the illness drives its protective response into overdrive. MIS-C, at its most intense, inflames critical organs, including the heart, lungs, brain and gastrointestinal system, according to the CDC.

Subscribe to our YouTube channel

Bloomberg Quicktake brings you live global news and original shows spanning business, technology, politics and culture. Make sense of the stories changing your business and your world.

To watch complete coverage on Bloomberg Quicktake 24/7, visit or watch on Apple TV, Roku, Samsung Smart TV, Fire TV and Android TV on the Bloomberg app.

Have a story to tell? Fill out this survey for a chance to have it featured on Bloomberg Quicktake

Connect with us on…

Breaking News on YouTube