Severe Acute Hepatitis of Unknown Origin in Children

Ontario’s CMOH Dr. Kieran Moore has released a Memorandum regarding cases of severe acute hepatitis of unknown origin in children in Europe and the United States.

Clinicians need to be vigilant of infants and children up to 16 years of age presenting with signs and symptoms compatible with acute hepatitis, including new onset of the following: jaundice (yellow skin and/or eyes) and discolouration of urine (dark) and/or faeces (pale).

  • Primary Care Providers and Paediatricians: Please read the entire memo (francais).
  • Public Hospitals: Please read the entire memo (francais). A CMOH Order under section 77.6 of the Health Protection and Promotion Act has been released and is available for download (francais) (PDF).


Monitoring Cases in Ontario

In response to this dynamic situation and to monitor cases in Ontario, Public Health Ontario is providing the following testing to individuals 16 years of age and younger undergoing investigation for hepatitis:

  • Acute Hepatitis A/B/C serology
  • EBV serology
  • CMV serology
  • Parvovirus serology
  • SARS-CoV-2 serology
  • Multiplex Gastrointestinal Virus PCR (including adenovirus)
  • Multiplex Respiratory Virus PCR (including adenovirus)
  • SARS-CoV-2 PCR


Testing Information

Pre-filled requisitions can be found on the Acute Severe Hepatitis of Unknown Origin in Children Test Information Sheet.


Additional Information

Contact the Public Health Ontario Customer Service Centre at 1-877-604-4567 (toll free) or 416-235-6556, or by email at

Last Updated: 24/05/2022