Ten children in Canada were found to be suffering from severe acute hepatitis not caused by known hepatitis viruses over a nearly six-month period recently, the Public Health Agency of Canada (PHAC) announced Friday.

Three cases were in Alberta, two in Manitoba, four in Ontario and one in Quebec. The children were between the ages of one and 13 years old. All children were hospitalized after becoming sick between Nov. 3, 2021, and April 23, 2022. Two children required a liver transplant.

The cases of severe acute hepatitis were not caused by known hepatitis viruses, such as hepatitis A, B, C and E, according to the agency.

The agency also said they are analyzing data to see if these reports represent an increase in frequency of cases of severe acute hepatitis in children not caused by known hepatitis viruses.

PHAC says it’s working with provinces and territories to identify cases dating back to October of 2021 to match the World Health Organization’s own investigation into severe acute hepatitis in children.PHAC added its investigation has been broad, including any children with inflammation of the liver where a cause is not certain.

Parents are asked to contact their child’s health-care provider if they notice any symptoms in their children, including yellowing of the skin and eyes, abdominal pain, nausea, vomiting, dark urine, light-coloured stools, loss of appetite, fever and fatigue.