Severe acute pediatric hepatitis of unknown origin: Update as of July 26, 2022

Update as of July 26, 2022, following reports of acute pediatric hepatitis cases in France and internationally. A case definition for healthcare professionals and guidelines on how to proceed are available on our website.

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Following the report shared by the United Kingdom regarding cases of severe acute hepatitis of unknown origin in young children, a standardized reporting system involving a network of clinicians and laboratories was established in France to detect any similar cases within the country. An initial case definition for healthcare professionals was thus published on May 3, 2022. Today, based on evolving knowledge and following further discussions with its network of partners (clinicians, laboratory professionals), Santé publique France is updating the case definition to improve its sensitivity and enable the identification of less severe cases, which may be more numerous. Additionally, the recommended course of action has been updated to reflect this new case definition.

Cases of acute pediatric hepatitis: Update as of July 26, 2022, in France and internationally

In France:

Nine possible cases have been reported, and one is currently under investigation by the medical teams treating the patients, in collaboration with Santé publique France. The occurrence of these cases is not unexpected and does not, at this stage, indicate an excess of cases in France.

Data on emergency department visits for hepatitis of unknown etiology from the OSCOUR® network are stable and do not indicate an excess of cases. Analysis of PMSI data for the first 16 weeks of 2022 shows that the number of hospital stays remains within the usual range for the 2018–2021 period, regardless of age group.

Internationally:

  • As of June 30, 2022, 200 cases of acute hepatitis of unknown origin in children aged 16 or younger had been reported by 19 European countries.

  • As of July 4, 2022, 263 cases of acute hepatitis of unknown etiology had been identified in children aged 10 or younger in the United Kingdom.

  • As of July 8, 2022, a total of 1,010 probable cases had been reported by 35 countries across five WHO regions; however, it is currently unclear whether these represent an excess of cases or the usual number of cases in most countries.

This update will be revised if there are significant developments in the situation in France.

A reporting system for suspected cases to complement syndromic surveillance

The formalized system for reporting and investigating possible cases, established in collaboration with the Ministry of Health, relies on a network of clinicians and laboratories, including the four liver transplant centers (Necker, Bicêtre, Marseille, Lyon) and pediatric intensive care units. Its objective is to detect any potential signal within the country similar to that observed in the United Kingdom.

The system is based on a new case definition developed in collaboration with pediatric hepatologists and the three National Reference Centers involved (for viral hepatitis B/C/Delta, gastroenteritis viruses, and respiratory infection viruses). The protocol for managing cases of severe acute hepatitis in children under 18 has consequently been updated and distributed by the Ministry of Health to the relevant healthcare professionals.

In addition, Santé publique France continues to regularly analyze:

  • emergency department visit data from the OSCOUR® network for a selection of diagnostic codes consistent with acute hepatitis of unknown etiology (excluding, in particular, viral hepatitis A through E) in children under 18 years of age, in order to identify any unusual increase in such cases in the recent period;

  • hospitalization data (PMSI) to detect any potential increase in the number of hospital stays consistent with acute hepatitis of unknown origin (data currently available through the end of January 2022).