Nonpolio Enteroviruses and the Febrile Infant

This chapter focuses on the epidemiology, clinical features, and laboratory aspects of nonpolio enteroviral infection in infants, primarily those less than 3 months of age. Despite many common clinical features, enteroviruses vary considerably in their organ tropism. The clinical manifestations of enteroviral infection are strikingly similar, despite the serotype-dependent differences in pathogenesis. On the basis of these clinical features, one cannot predict the presence or absence of enteroviral meningitis. Furthermore, there is considerable overlap in the signs and symptoms caused by the various viruses that are associated with febrile illness in young infants. The distinctive as well as overlapping features of disease caused by enteroviruses, respiratory syncytial virus, and influenza viruses in the young infant are illustrated. Despite the increasing emphasis on rapid diagnostic techniques for direct detection of viral antigens and nucleic acid, virus isolation in cell culture remains the only reliable way of demonstrating most enteroviruses in clinical specimens. Virus culture of specimens from multiple sites, perhaps with the addition of PCR techniques, can provide a sensitive, rapid, often specific diagnosis of enteroviral disease in symptomatic young infants.