Neonates, or newborns, are particularly vulnerable to enterovirus infections due to their immature immune systems. Enteroviruses can cause a range of illnesses in neonates, from mild febrile illnesses to severe, life-threatening conditions. Serious complications can include myocarditis, meningitis, encephalitis, and neonatal sepsis. The severity of the illness often depends on the type of enterovirus involved and the overall health of the neonate.