Case numbers of acute hepatitis of unknown aetiology among children in 24 countries up to 18 April 2022 compared to the previous 5 years

Abstract

An increase of acute hepatitis of unknown aetiology has been reported among children in multiple countries worldwide. With a rapid online survey among hospitals in and outside of Europe, we describe case numbers recorded from 1 January to 18 April 2022 vs the previous 5 years. Of 24 countries that responded, we identified 5/17 European and 1/7 non-European countries with an elevation in probable cases of unexplained acute hepatitis, and severe cases were elevated in five European countries.

Diagnosis, treatment, and prevention of severe acute hepatitis of unknown etiology in children

“…Most patients have gastrointestinal symptoms in the early stages, including diarrhea (45%), abdominal pain (42%), and nausea (31%). Some present with fever (31%) and respiratory symptoms (19%) [ 1 , 3 ]. Hepatomegaly is common, but splenomegaly is rare.…”

“…Meanwhile, 9 cases were retrospectively identified from October 2021 to February 2022 at a children’s hospital in Alabama, USA [ 2 ]. As of April 18, 2022, the number of cases reported by 6 of the 24 countries around the world is at least 3 times higher than the annual average number of cases in the previous 5 years [ 3 ]. On April 23, the WHO reported 169 cases in Europe, America and Asia; 17 cases (10%) needed liver transplantation (LT), and at least one patient died [ 4 ].…”

“…The UK Health Security Agency (UKHSA), European Centre for Disease Prevention and Control, CDC and WHO have issued a warning and provided case definitions, investigation methods, reporting systems, prevention and control advice [ 3 , 4 , 6 – 8 ]. This review summarizes the current available information regarding the outbreak of severe acute hepatitis and introduces our hospital’s previous experiences with the diagnosis and treatment of severe acute hepatitis for reference.…”

Response to the outbreak of severe acute hepatitis of unknown origin in children

“…So what is the cause of these children's sudden hepatitis? Based on the current global case investigation and comprehensive information from the European Centers for Disease Control and Prevention (ECDC), the UK National Health Security Agency, and the USA Centers for Disease Control and Prevention (CDC), potential causes are speculated including adenovirus (HAdV) infection (normal adenovirus or new variant adenovirus), SARS-CoV-2 virus post-infection syndrome or SARS-CoV-2 new variant strain infection, drug, toxin or environmental exposures, unknown pathogens alone or coinfection [1,[8][9][10][11][12][13].…”

Note from the editors: Acute hepatitis among children, establishing evidence and baselines for comparison

“…They show that at the start of a possible outbreak with a yet unknown aetiology but features suggestive of an infectious cause, it is challenging to establish a sound evidence-base and to measure increase against a baseline of a syndrome or disease which is not under systematic surveillance and governed by standard case definitions. The short communications by van Beek et al [ 1 ] and de Kleine et al [ 2 ] both report results on quick surveys among different networks of clinical experts working with (paediatric) liver diseases and use different approaches to try and shed light on whether there is—or is not—a widespread increase. Both cover a similar period in 2022 and apply a similar case definition for acute hepatitis of unknown aetiology.…”