ECDC and WHO have published Joint ECDC-WHO Regional Office for Europe Hepatitis of Unknown Origin in Children Surveillance Bulletin. The surveillance summary:
This report provides an overview of the cases of hepatitis of unknown origin in children aged 16 years and below reported to ECDC and the WHO Regional Office for Europe through The European Surveillance System (TESSy) hosted at ECDC.
As of 13 May 2022, 232 cases of acute hepatitis of unknown aetiology in children aged 16 years or below have been reported, of which 229 were classified as probable and three as epidemiologically linked, by 14 countries (Belgium (12), Cyprus (two), Denmark (six), Greece (two), Ireland (six), Italy (24), the Netherlands (six), Norway (five), Poland (one), Serbia (one), Slovenia (one), Spain (26), Sweden (nine), and the United Kingdom (131)).
Of the 229 probable cases, 122 have recovered, while 18 remain under medical care.
The epicurve shows cases by the date of onset of first symptoms of disease. An increase in the number of cases has occurred from week 9. As severe hepatitis can take some time to develop after the onset of the first symptoms and as investigations take time, there may be a delay in the reporting of cases. The recent decrease in cases is therefore challenging to interpret.
The majority (75.9%) of cases are <5 years of age.
Of 143 cases with information, 22 (15.4%) were admitted to an intensive care unit. Of the 98 cases for which this information was available, six (6.1%) have received a liver transplant. There has been one death associated with this disease.
Overall, 151 cases were tested for adenovirus by any specimen type, of which 90 (59.6%) tested positive. The positivity rate was the highest in whole blood specimens (68.9%).
Of the 173 cases PCR tested for SARS-CoV-2, 20 (11.6%) tested positive. Serology results for SARS-CoV-2 were only available for 19 cases, of which 14 (73.7%) had a positive finding. Of the 56 cases with data on COVID-19 vaccination, 47 (83.9%) were unvaccinated.