"We're getting more of these MIS-C kids now, but this time it just seems like a higher percentage of them are really seriously ill," said Dr. Roberta DeBiasi, Infectious Disease Director at Children's National Hospital in Washington. DC During the first wave of the hospital, roughly half of the patients needed intensive care treatment, but now 80 to 90 percent do.
The reasons are unclear. The increase follows the general increase in Covid cases in the US after the winter holiday season, and more cases may simply increase the likelihood of serious illnesses occurring. So far, there is no evidence that newer coronavirus variants are responsible, and experts say it is too early to speculate on the effects of variants on the syndrome.
The condition remains rare. The latest numbers from the Centers for Disease Control and Prevention show 2,060 cases in 48 states, Puerto Rico and the District of Columbia, including 30 deaths. The mean age was 9 years, but infants up to 20 years of age were affected. The data, which are not complete until mid-December, show that the case rate has increased since mid-October.
While most young people, including those who became critically ill, survived in relatively healthy condition and went home, doctors are not sure if they will experience persistent heart or other problems.
"We really don't know what's going to happen in the long run," said Dr. Jean Ballweg, Medical Director of Pediatric Heart Transplant and Advanced Heart Failure at the Children's Hospital and Medical Center in Omaha, Neb., Where April through October. The hospital treated about two cases per month, about 30 percent of them in the intensive care unit that rose to 10 cases in December and 12 in January, with 60 percent being I.C.U. Care – most require ventilators. "Obviously they seem sicker," she said.