On 12 May, a Rapid Communication on the reported increase of acute hepatitis of unknown origin in children was published in Eurosurveillance. The paper outlines the extent and geographical distribution of these unexplained paediatric hepatitis cases in Europe and beyond. It also highlights the challenges of drawing comparisons against a baseline of a syndrome which is not under systematic surveillance and has no standard case definitions in place.
Acute hepatitis of unknown origin is a rare paediatric syndrome, which causes severe inflammation of the liver and may require transplantation. Lately, multiple countries have reported an increasing number of children acquiring this rare form of hepatitis. In early May, the UK International Health Regulations National Focal Point reported 163 cases, 11 of which required liver transplants. According to the European Centre for Disease Prevention and Control, at the end of April, approximately 55 cases were reported from 12 EU countries, 12 cases from the United States, 12 from Israel, and 1 from Japan.
Penta was among a group of European clinical trial networks and paediatric gastroenterology and infectious diseases societies that contributed to data collection by developing and distributing a rapid online survey to Penta ID Network members. The survey aimed to quickly assess the extent, geographical distribution and potential aetiology of the outbreak in Europe in the first four months of 2022, compared to the incidence rates in the previous 5 years. Participating hospitals were asked to report the number of possible, probable, and severe possible and probable cases according to case definitions. 52 hospitals in 17 European and 7 non-European countries responded to the survey, 13 of which were liver transplantation centres.
Compared with previous years, the incidence of paediatric cases of probable acute hepatitis of unknown origin appears to be higher in 5 out of 17 surveyed European countries and 1 out of 7 non-European countries, the UK seeming particularly affected. Adenovirus has been identified as a possible causative agent, with possible co-factors being the lack of prior adenovirus exposure because of COVID-19 public health measures, co-infection with SARS-CoV-2 or other pathogen, or a toxin, drug, or environmental exposure.
The Rapid Communication provides insight in the form of current ‘best available evidence’. However, additional epidemiological and clinical investigations are needed to establish if there is an excess of acute hepatitis cases of unknown origin in children, which would require targeted studies to determine its cause. Penta remains available to support this process. We thank all the members who contributed to the data collection by filling in the survey.
Read the Rapid Communication here.