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Public Health Wales reassures parents after cluster of enterovirus cases investigated

Published: 3 May 2023

Public Health Wales doctors are reassuring parents after a very small number of cases of a rare complication of enterovirus has caused myocarditis in very young babies.

Ten babies from the South Wales area have been given hospital treatment for the infection since June 2022.  All were under one month old.  Very sadly, one baby has died.

Public Health Wales is stressing that this reaction to the infection remains extremely rare.  Dr Christopher Williams, consultant epidemiologist for Public Health Wales, said;

“Enterovirus is a common infection of childhood, causing a range of infections including respiratory disease, hand, foot and mouth, and viral meningitis.  In very young babies, enterovirus can, in rare cases, also cause a severe illness in the first few weeks of life. Most babies and children recover completely following enterovirus infection.

“It only affects the heart on very rare occasions. This cluster is unusual due to the number of cases reported in a relatively short time frame, and so investigations are now ongoing in collaboration with the paediatric team in the children’s hospital of Wales to understand the reasons why and to investigate any further cases that may be reported in the coming weeks and months.

“Parents should be reassured that although there has been an increase in cases, this is still an extremely rare occurrence.”

Parents and carers should take care to practice good hand hygiene – including washing hands thoroughly before and after changing nappies, after using the toilet, and before preparing food.
Public Health Wales are issuing a briefing to health professionals in Wales to inform them of the cluster.

No outbreak has been declared.

This increase in cases of myocarditis (inflammation and damage to the heart) in very young babies in Wales is still being investigated, we are working with experts here and across the UK to try to understand this further.

Enterovirus is a common infection that spreads through the population every year, with larger outbreaks occurring regularly, often every three years.

Severe disease and myocarditis is a well-recognised complication of this infection, but is very rare. While there has been an increase in the number of cases in very young babies (under one month old), it still remains rare.

The best way to prevent infection with enterovirus, as well as other viruses, is by simple hygiene measures such as hand washing especially after changing nappies, going to the toilet or blowing your nose.

Most viral infections in babies are mild, but if you are concerned your baby is unwell please seek medical attention.

Enterovirus infection is a very common seasonal childhood illness, and causes the usually mild infections that are often picked up in childhood such as hand foot and mouth disease. 

In some rare cases, such as in very young babies under one month old, enteroviruses can cause severe infection, such as myocarditis, viral meningitis or sepsis.

The individual risk from transmission of enterovirus is very low, and the severe myocarditis cases have been in babies under one month old.  Prevention of transmission to other individuals in a household or ward is through usual hygiene measures such as hand washing, hygienic disposal of nappies and regular cleaning of touch points and surfaces.

If your baby has a fever please follow the advice from NHS 111 Wales.

Severe enterovirus cases have been showing features of sepsis.  You can find out more information on sepsis on this page.  

Public Health Wales, working with colleagues around the UK and the ISARIC researchers, are still looking into factors which might contribute to severity of infection. We are not able to give details on individual cases.