Neonatal Enteroviral Myocarditis (NEM)
Information on the reporting, investigation and management of Neonatal Enteroviral Myocarditis (NEM).
Information on the reporting and investigation of neonatal myocarditis
Enteroviruses are a common cause of seasonal childhood infections and typically cause respiratory disease, hand-foot-and-mouth and viral meningitis. The vast majority of infections are mild and self-limiting. Neonates can, however, rarely develop severe enterovirus infection, which may present as a sepsis-like syndrome or viral meningitis. Myocarditis (inflammation of the heart muscle) is a very rare complication of enterovirus infection, and typically associated with coxsackie B viruses.
Enterovirus myocarditis is associated with high morbidity and mortality, especially in neonates, and can lead to severe complications, including heart failure, arrythmias and haemophagocytic lymphohistiocytosis (HLH).
Current situation and interpretation
In April 2023, the UK Health Security Agency (UKHSA) and Public Health Wales began investigating a cluster of NEM with cases reported since June 2022. The neonates presented to hospital severely unwell and required admission to the paediatric intensive care unit (PICU), often for prolonged periods.
All cases tested positive for enterovirus and, where subtyping was performed, were identified as coxsackie B3 or B4. EDTA blood PCR was the most frequently positive sample type, followed by respiratory samples. Enterovirus was less frequently detected in stool in the neonatal cases.
In neonates presenting with respiratory distress, sepsis, meningitis or shock, clinicians should test for enteroviruses and consider an underlying myocarditis. Myocardial dysfunction can be identified by measuring cardiac enzymes, electrocardiography and echocardiography. In such cases, the minimum sample set for enterovirus testing includes EDTA blood, an upper respiratory tract sample (throat swab, nasopharyngeal swab and/or nasopharyngeal aspirate), stool sample and, if clinically indicated, cerebrospinal fluid.
On 2 May 2023, UKHSA declared a national routine incident to coordinate prospective and retrospective NEM case finding across the UK.
Regulation 2(1)(b) of the Health Protection (Notification) Regulations 2010 place a duty on registered medical practitioners (RMPs) to report any suspected infections that present or could present significant harm to human health. This covers reporting of neonatal enteroviral myocarditis.