The World Health Organisation (WHO) has issued an alert about a cluster of cases of severe myocarditis in Wales and South West England linked to enterovirus infection.
UK officials had notified WHO in April after PCR testing had identified an increase in severe myocarditis in babies admitted to hospital associated with enterovirus infection in Wales followed by five cases identified in England.
Ten cases were Wales between June 2022 and April 2023, with a peak in November, and five cases in South West England over the same period.
In the Welsh cases, seven of the ten cases had further subtyping, with either coxsackie B3 or coxsackie B4 identified, WHO said.
All patients needed intensive care and one infant died, the alert said.
A UK incident management team is reviewing the evidence and investigations are ongoing as to whether the two clusters are linked.
Dr Shamez Ladhani, consultant paediatrician at UKHSA, said: ‘Enterovirus is a common infection of childhood, causing a range of symptoms including respiratory disease; hand, foot and mouth, and viral meningitis.
‘In very young babies, enterovirus can, on rare occasions, lead to a severe complication called myocarditis – which causes inflammation of the heart. Most babies and children recover completely from this.
‘Given a higher than average number of cases in Wales in the autumn/winter months in very young babies, UKHSA is investigating the situation in England to see if any similar cases have been observed here and whether there are any factors driving the increase in cases.’
A statement from Welsh health minister Eluned Morgan said Public Health Wales was investigating the cases.
‘Parents should be reassured that although there has been an increase in cases, this is still an extremely rare occurrence. Paediatricians in Wales have been advised and will continue to consider the possibility of myocarditis in babies presenting with sepsis.’
In February, NHS England retired interim clinical guidance which lowered the threshold for prescribing antibiotics with potential strep A infections, following a recent reduction in infection rates.