Toronto joins the list of cities around the world currently reporting mysterious cases of hepatitis in children.
Seven cases of severe acute hepatitis — cause unknown — were reported by Sick Children’s Hospital on May 9; they were diagnosed between October 2021 and April of this year.
This month, some 20 countries have reported more than 350 cases of pediatric hepatitis of unknown origin. Children have died (five in the U.S., according to the Centres for Disease Control and Prevention ) at least 18 needed liver transplants.
The U.K. has seen more than 160 cases.
The WHO reported that there are cases as well in India, Israel, South East Asia, Ireland, Holland and several other European countries. There are reports of a significant increase in these cases, and the severity of the liver inflammation has also been noted.
Whether the cases in Toronto are occurring in unusually high numbers is not known.
According to a statement from the hospital: “It remains to be seen whether this number represents an increase in cases of unknown origin compared to similar time periods in previous years, or if any of these cases will be confirmed to be caused by a novel clinical entity.”
The cases are not linked to hepatitis viruses or to any other usual causes. Researchers are looking at evidence that links the liver inflammation to adenovirus infections — colds, flu and other common ailments — and to COVID-19, or a combination of both.
There is a growing body of evidence that this hepatitis in children may be a post-viral (i.e., post-COVID) issue. According to the WHO, the majority of cases it reviewed are in children who are not vaccinated.
Some physicians cautioned against believing adenoviruses to be the culprit, because severe illness caused by adenoviruses is almost always seen in the immunocompromised.
And adenovirus infection is common in children, often found in samples from tonsils or adenoids.
Internist/gastroenterologist Dr. Farid Jalali, for example, wrote that adenovirus is probably a red herring in the pursuit of causes of this hepatitis in children.
As the Journal of Paediatric Gastroenterology & Nutrition reported this month, a three-year-old with acute liver failure (due to type 2 Autoimmune Hepatitis Associated With SARS-CoV-2 Infection) was successfully treated with steroids, avoiding the need for a liver transplant.
The researchers wrote: “This case highlights a possible association between SARS-CoV-2 infection and subsequent development of autoimmune liver disease, presenting with acute liver failure.”
The paper addresses evidence of a connection between Covid (SARS-CoV-2) and several autoimmune diseases, concluding: “Although it is impossible to directly prove that SARS-CoV-2 infection caused Autoimmune Hepatitis in this patient, the temporal association of infection with subsequent liver failure cannot be ignored.”