British Columbia and Alberta have become the latest provinces in Canada to investigate cases of an unusual syndrome in children, which doctors around the world are studying to see if there's a definitive link to COVID-19.
The Hospital for Sick Children in Toronto and Montreal's Sainte-Justine Hospital are each examining 20 possible cases of Multisystem Inflammatory Syndrome in Children, or MIS-C.
Earlier this week, Alberta's chief medical officer of health announced doctors are looking into one suspected case in the province, while British Columbia said it is investigating half a dozen cases.
"Because there isn't really a definitive, one specific test that says, 'yes, you have multisystem inflammatory syndrome' or 'you don't,' I don't think that the cases themselves are 100 per cent clearly defined from children who might have some other type of infection," said Dr. Jeremy Friedman, the associate chief of pediatrics at SickKids.
"It might take a little bit of time to really be absolutely certain about how many cases that are being investigated are actually truly related to COVID."
Friedman's team at the Toronto hospital have also been in contact with the study at Sainte-Justine run by Marie-Paule Morin, a pediatric rheumatologist.
This month, the U.S. Centers for Disease Control and Prevention issued an alert to doctors about MIS-C. The agency's case definition includes current or recent COVID-19 infection or exposure to the virus, a fever of at least 38 C for at least 24 hours, severe illness requiring hospitalization, inflammatory markers in blood tests, and evidence of problems affecting at least two organs that could include the heart, kidneys, lungs, skin or nervous system.
The CDC said some children may have symptoms resembling Kawasaki disease, a rare condition that can cause swelling and heart problems.
In other parts of the world, the illness is also called Pediatric Inflammatory Multisystem Syndrome (PIMS).
Dr. Deena Hinshaw, Alberta's chief medical officer of health, said Wednesday that while little is known about MIS-C, "it seems to be more something that happens as a result of (a child's) immune system going into overdrive after an infection and causing this inflammatory response in multiple organs."
Hinshaw gave little information about the province's first suspected case, other to say that the child is stable in hospital.
In Toronto, Friedman said one of the 20 children had to be admitted to an intensive care unit. All have responded well to treatment and have gone home.
There have been no reported deaths linked to MIS-C in Canada, but some children have died from the illness in New York, France and the United Kingdom.
Friedman said it is "highly suspicious" that there seems to be an increase in children presenting MIS-C symptoms about a month after the peak in the number of COVID-19 infections in their communities.
"That seems to be a consistent time that people are seeing this uptick," he said.
But Friedman noted that none of the children at SickKids tested positive for an active coronavirus infection. His team has blood samples from each child that will then be tested for COVID-19 antibodies.
Although Health Canada has recently approved two serological tests, Friedman said he is waiting to hear from provincial experts on which one is most accurate.
The Canadian Paediatric Society recently published MIS-C guidelines for clinicians and caregivers and is tracking and studying the illness nationwide.
"This syndrome is still very new, and scientists and doctors are learning about it in real time," the society said in an email Friday.
"The CPSP study will provide essential, timely information about how children are being affected, which children are at highest risk, and will enable us to adjust best practices for prevention and care based on evidence."
Friedman said parents should be vigilant about signs of MIS-C, but they shouldn't be alarmed since the numbers are low and the condition is treatable.
"This is definitely going to add to what we know about COVID and hopefully some aspects of what we learn will inform the development of vaccines," he said.
"It's quite reassuring to know that we can all learn from each other and that is happens in a pretty rapid sequence."
This report by The Canadian Press was first published May 29, 2020
— With files from The Associated Press
Daniela Germano, The Canadian Press