On 31 March 2022, Public Health Scotland (PHS) were notified of five children aged three-to-five-years that were diagnosed with severe hepatitis of unknown origin at the Royal Hospital for Children.[6] On 5 April, the International Health Regulations (IHR) National Focal Point (NFP) for the UK informed the WHO of 10 cases of sudden severe hepatitis of unknown origin in children across Scotland, one whose symptoms began in January while the others first became unwell in March.[7] They were previously healthy.[8] By 8 April 2022, cases identified in the UK totalled 74, with six requiring a liver transplantation.[7][9] Subsequently a few cases were reported in Ireland and Spain.[7] By 21 April, there were 108 cases in the UK.[10]