TORONTO -- The Ontario government said it's taking immediate action after an increase in a mysterious inflammatory illness in children that could be connected to COVID-19.

Health officials say the illness appears to be similar to Kawasaki Syndrome, a rare but serious inflammatory disease. Symptoms associated with this illness include persistent fever, abdominal pain, and gastrointestinal symptoms, including nausea, vomiting and diarrhea, as well as a rash.

Health Minister Christine Elliott said that in consultation with Ontario's Chief Medical Officer of Health, Dr. David Williams, the government is immediately updating the case definition of COVID-19 to include multisystem inflammatory vasculitis as an atypical symptom in children.

"This will support clinicians in making clinical assessments of patients who may have symptoms, including some of the most vulnerable of patients, children," Elliott said in a statement on Wednesday morning.

"Recent reports in Canada and internationally indicate that there may be an increase in multisystem inflammatory vasculitis, a rare but serious multisystem inflammatory illness that impacts children who have been diagnosed with COVID-19.”

Elliott said that recent data in Canada indicates the majority of COVID-19 infections in children are mild and do not require hospitalization. People under the age of 19 make up just five per cent of cases in the country and no children are known to have died. 

Meanwhile, associate pediatrician-in-chief at The Hospital for Sick Children, Dr. Jeremy Friedman, told CTV News Toronto on Tuesday that reports of the inflammatory illness has put staff on "high alert."

Read more: Rare, potentially deadly illness in children prompts alert to Canadian doctors

Kawasaki Syndrome

"It certainly is highly suspicious that it seems to be related to the COVID-19 pandemic and obviously that’s going to put us on high alert," Friedman said.

He said he is aware of the reports children are “presenting quite sick” with an illness that is similar to Kawasaki Syndrome.

"Based on what we’ve heard from European countries from U.S. and now from Montreal, it would come as a big surprise to me if we don’t see a start to see a few cases over the next few weeks.