Following the report shared by the United Kingdom relating to cases of severe acute hepatitis of unknown origin in young children, a standardized information feedback system involving a network of clinicians and laboratories has been set up. in France to detect a possible similar signal on the territory. An initial case definition for healthcare professionals was thus published on May 3, 2022. Today, based on the evolution of knowledge and after new exchanges with its network of partners (clinicians, biologists), Public Health France is adapting the case definition to improve its sensitivity and be able to identify less severe cases, and therefore potentially more numerous. In addition, the course of action has been updated to take this new case definition into account..
A circuit for reporting possible cases in addition to syndromic surveillance
The formalized system for reporting and investigating possible cases, in conjunction 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 on the territory a possible signal similar to that observed in the United Kingdom.
The system is based on a new case definition developed in collaboration with hepato-pediatricians and the three National Reference Centers involved (viral hepatitis B/C/Delta, gastroenteritis viruses and respiratory infection viruses) . The action to be taken in the event of severe acute hepatitis in children under 18 has therefore been updated and disseminated by the Ministry of Health to the professionals concerned.
In addition, Public Health France continues to regularly analyze:
- emergency room visit data from the OSCOUR® network for a selection of diagnostic codes compatible with acute hepatitis of unknown etiology (notably excluding viral hepatitis A to E) in children under 18 in order to identify a possible increase unusual number of these cases over the recent period;
- hospitalization data (PMSI) to be able to detect a possible increase in the number of hospital stays compatible with acute hepatitis of unknown origin (data currently available until the end of January 2022).
Why are we changing the case definition?
The first definition relating to pediatric cases of acute hepatitis was developed with the objective of rapidly identifying severe cases of unknown origin and characterizing them precisely. The investigation circuit set up in conjunction with the Ministry of Solidarity and Health identified 2 cases. It is not possible in the current state of knowledge to know if there is a link between these cases and the signal reported by the United Kingdom.
After further exchanges with its network of partners (clinicians, biologists), Public Health France is adapting the case definition to improve its sensitivity and be able to identify less severe cases, and therefore potentially more numerous.
What’s new ?
The main changes made to the case definition were discussed with the Agency’s network of partners, in particular hepato-paediatricians and virologists. They concern, among other things:
- The systematic consideration of cases of acute hepatitis with infection by SARS-CoV-2 or by an adenovirus.
- The withdrawal of the criterion of a prothrombin level below 50% (criterion of severity marking major liver dysfunction) in order to extend the collection to less severe hepatitis.
- A clarification of the exclusion factors of the definition of a possible case and in particular: hepatotoxicity linked to a drug, the viruses classically responsible for acute hepatitis, and the other well-known causes that can lead to acute hepatitis.
These changes should result in more cases being reported. These cases are not unexpected in France but reporting them will allow them to be thoroughly investigated and linked, if necessary, to the alert in the United Kingdom.
The publication of this case definition is for investigation and epidemiological surveillance purposes, but does not modify the medical care of the children concerned.
Cases of pediatric acute hepatitis: update on 05/23/2022 in France and abroad
In France :
Two possible cases have been reported and 4 are being investigated by medical teams, in conjunction with Public Health France. The occurrence of these cases is not unexpected and does not reflect, at this stage, an excess of cases in France.
Internationally :
- As of 19 May 2022, 125 cases of acute hepatitis of unknown origin in children aged 16 years or younger have been reported in 14 European countries.
- As of May 16, 2022, 197 cases of acute hepatitis of unknown etiology have been identified in children aged 10 years or younger United Kingdom.
- In other countries, as of May 19, 2022, 313 cases of acute hepatitis in children have been reported by 16 countries, without it being possible at the present time to know whether they represent an excess of cases or s This is the usual number of cases in most countries.
A total of 614 cases have been reported worldwide.
