Since the start of the novel coronavirus pandemic, a total of 11 children in Washington state have been hospitalized with a rare but serious syndrome that appears to be triggered by infection with the virus, state health officials said Friday.

The state’s first four cases were reported in May, and seven other children have been stricken since then, said Dr. Marisa D’Angeli, an epidemiologist at the Washington Department of Health. The pattern of cases roughly tracks the resurgence of infections across the state this summer.

All of the children were very sick, D’Angeli said. The majority were in intensive care and some required mechanical ventilation. No children have died in Washington either from regular coronavirus infections or the associated syndrome.

Called Multisystem Inflammatory Syndrome in Children, or MIS-C, the little-understood condition can affect the heart, kidneys and gut. Symptoms include high fever, rash, swelling, abdominal pain, diarrhea and vomiting. The cause seems to be a runaway immune response that flares after the initial coronavirus infection, said Dr. John McGuire, chief of critical care at Seattle Children’s, where eight of the 11 kids were treated.

“These kids feel terrible,” he said. “They’re tired, weak, achy, they have pretty high fevers. They feel completely wiped out.”

But the good news is that all of the children have responded well to treatment, with no apparent long-term effects.


“We’ve been really pleased with their recovery,” McGuire said.

Most of Washington’s initial cases of MIS-C were in Western Washington, where the virus took hold first. Now, most cases are being diagnosed in Central Washington, following the recent spike of cases there, McGuire said.

King and Yakima counties have seen three cases each. Franklin and Snohomish counties have two cases each, and Skagit County has one. About 12 percent of Washington’s confirmed coronavirus infections — or about 7,300 cases — have been in children or teenagers.

As with adult coronavirus infections across the state, children of color have been disproportionately impacted by MIS-C, D’Angeli said. Of Washington’s confirmed cases of the syndrome, 55 percent are Hispanic, 18 percent are white, and 9 percent are each Black, Asian and American Indian or Alaska Native.

The average age of the children was eight, with six of them under the age of 10 and five age 10 or older.

Nationally, 570 children were diagnosed with MIS-C through July 29, with 10 fatalities, according to a CDC report published Friday.

Most kids infected with the novel coronavirus have very mild symptoms. It’s not clear why a tiny percentage go on to develop the inflammatory syndrome, McGuire said. The CDC report singled out obesity as the most common underlying medical condition, but few of the kids in Washington had any underlying health problems, he added.


McGuire and Seattle Children’s are part of a national collaboration to pool data about MIS-C in order to identify risk factors and the most effective treatments. Since cases seem to lag infection peaks by four to six weeks, McGuire said he expects to see the next wave of kids with MIS-C in states like Arizona, Texas and Florida.

He advises parents to be aware, but not worried. Some of the warning signs include a high fever that lasts for more than three days and other flu-like symptoms that seem to get progressively worse.

“This is quite uncommon,” McGuire said. “The kids who get this are sicker than even that bad case of flu.”

Right now, the best way to protect children is to stop the spread of the virus, D’Angeli said. “We all need to do our part by washing our hands, maintaining social distance, wearing masks and avoiding big gatherings.”