Question Period Note: Acute and severe hepatitis in children

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• Beginning in early April 2022, the World Health Organization (WHO) reported an increase in cases of acute severe hepatitis in children not caused by known hepatitis viruses. The Public Health Agency of Canada (PHAC) is collaborating with provincial and territorial health partners across the country to investigate cases in Canada. As of August 31, 2022, 26 cases of acute severe hepatitis in children that meet the national case definition have been identified in Canada. PHAC continues to work with its provincial and territorial health partners to further investigate these cases.
• Keeping people in Canada safe from threats to their health, and keeping our most vulnerable citizens safe and healthy, is a top priority of the Government of Canada.
• The Public Health Agency of Canada is working closely with provincial and territorial health partners to further investigate cases in Canada. All provinces and territories are continuing to identify and report potential cases to the Agency so that the national scope of the investigation can be further defined.
• This is an evolving investigation, both in Canada and internationally. More information is needed to assess the situation and any potential risks to people in Canada. As the investigation evolves, the Public Health Agency of Canada will provide updates to the public.

If pressed on a link to COVID-19 vaccination:
According to the World Health Organization, side effects from the COVID-19 vaccines are not suspected to be the cause of illnesses as the vast majority of affected children did not receive COVID-19 vaccination.

Investigation into acute severe hepatitis in children
On April 5, 2022, the World Health Organization (WHO) was notified of 10 cases of acute hepatitis of unknown etiology in children under 10 years of age in Scotland. Since then, further reports of cases have continued to be reported internationally, with the majority of cases to date reported from the United Kingdom. As of July 8, 2022, 1010 probable cases have been reported to the WHO among children 16 years of age and younger from 35 countries. Forty-six (5%) children have required liver transplants. At least twenty-two (2%) deaths have been reported to the WHO.
PHAC is working closely with provincial and territorial health partners to identify and investigate cases in Canada.

Acute severe hepatitis in children is a relatively rare condition that does occur in Canada. In many cases, an underlying or contributing cause is unknown. It is important to note that the definition being used to include cases in the national investigation is very broad. This means that any children with acute severe hepatitis (inflammation of the liver) where a cause is not certain are being included in initial investigations. Some of these children may have a diagnosis for their liver condition, but they are being included to explore possible factors that may have triggered the condition.

The cause of illnesses reported internationally is unknown at this time and active investigation continues in multiple countries. The leading hypothesis is that co-infection with adeno-associated virus 2 (AAV2) and an adenovirus, or less often herpes virus HHV6, leads to the development of acute severe hepatitis. According to the WHO, side effects from the COVID-19 vaccines are not suspected, as the vast majority of affected children were too young and did not receive COVID-19 vaccination.
PHAC’s involvement in the investigation
PHAC is collaborating with provincial/territorial public health partners to coordinate an investigation into potential cases of acute severe hepatitis in children not caused by known hepatitis viruses. Case definitions, case report forms, and reporting processes have been established and shared with all partners. PHAC is connecting with international health partners to collect more information about their investigations. All cases identified in Canada are being reported to the Pan-American Health Organization and the WHO.
The National Microbiology Laboratory, in collaboration with the Canadian Public Laboratory Surveillance Network, has developed laboratory guidelines for testing cases of acute severe hepatitis in children not caused by known hepatitis viruses in Canada, and these have been shared with provinces and territories.
Symptoms of hepatitis
Symptoms of acute severe hepatitis include jaundice (yellowing of the skin and eyes), abdominal pain, nausea, vomiting, dark urine, light-coloured stools, loss of appetite, fever, and fatigue. Even in cases where the cause of acute severe hepatitis is unknown, treatment is available, and most children recover with medical care.

Public Communication
On May 10, 2022, PHAC provided an initial media statement to several media outlets on this evolving issue. On May 20, 2022 PHAC issued an updated media statement to first report the number of cases in Canada. As the investigation evolves, PHAC will provide updates to the public.

• Hepatitis is a term for liver inflammation. Depending on the cause, the disease can be very sudden and progress to liver failure over a few days to weeks (called acute).
• Acute severe hepatitis in children is a relatively rare condition that does occur in Canada. In many cases, an underlying cause cannot be found. Even in cases where the cause of acute severe hepatitis is unknown, treatment is available and most children recover with medical care.
• As of August 31, 2022, 26 cases of acute severe hepatitis in children not caused by known hepatitis viruses have been identified in Canada in 5 provinces: British Columbia (1), Alberta (5), Manitoba (3), Ontario (13), and Quebec (4). The children are between <1 and 13 years of age, and became sick between November 3, 2021, and August 11, 2022. All children were hospitalized. Two children have required liver transplants. No deaths have been reported.