UK authorities are investigating an “unusual” surge in severe myocarditis which has hit 15 babies in Wales and England and has killed at least one, the World Health Organisation has announced. On Tuesday, the WHO issued an alert that there had been a rise in “severe myocarditis” in newborns and infants between June 2022 and March 2023 in Wales and England. It said that this was associated with the enterovirus infection, which rarely affects the heart.
A UK Health Security Agency (UKHSA) spokesperson confirmed to sources that 10 babies have been diagnosed in Wales and five have been diagnosed in England. The WHO said that “although enterovirus infections are common in neonates and young infants, the reported increase in myocarditis with severe outcomes in neonates and infants associated with enterovirus infection is unusual.”
It said that in the same hospital (covering the South Wales region) over the previous six years, “only one other similar case has been identified.” WHO assessed the public health risk as low, but added that in certain situations, it “may be advisable to close child-care facilities and schools to reduce the intensity of transmission.” However, the WHO took down the alert on Wednesday. This could be because some of the numbers were not correct.
Authorities in England and Wales are currently investigating the rise in cases. Public Health Wales at the start of May announced that it was investigating a cluster of severe enterovirus infections with myocarditis occurring in very young babies from the South Wales region.
The cases occurred from June 2022 with a peak in November 2022 involving babies under 28 days old. Ten babies have developed myocarditis within this cluster. One baby remains in hospital, eight are being managed as outpatients, and one baby has died.