Perinatal echovirus and group B coxsackievirus infections.

Enteroviral infections late in pregnancy are common, especially during periods of high prevalence of community infection. Most of these infections, however, are not associated with significant maternal or neonatal disease. Conversely, as many as 65 per cent of women who give birth to infants with proven enteroviral infection have symptomatic disease during the perinatal period. Maternal echovirus or coxsackievirus B infections are not associated with an increased risk of spontaneous abortions, but stillbirths late in pregnancy have been described. Although a slightly increased risk for congenital heart defects and urogenital anomalies has been reported for the offspring of women who seroconverted to the group B coxsackievirus during pregnancy, these data are highly tentative. Transmission of enteroviruses from mother to infant is relatively common (30-50 per cent) and may occur through contact with maternal secretions during vaginal delivery, blood, or upper respiratory tract secretions. Intrauterine transmission has been documented, but its frequency is unknown. Postnatal transmission from maternal or nonmaternal sources also occurs regularly. Neonatal disease may range from inapparent infection to overwhelming systemic illness and death. Common clinical syndromes associated with neonatal enteroviral infections are meningoencephalitis, pneumonia, myocarditis, and hepatitis. The severity and outcome of perinatally acquired enteroviral infection is influenced by several factors, including the virus strain involved, mode of transmission, and presence of passively acquired serotype-specific maternal antibody. Newborn nursery outbreaks of nonpolio enteroviral infections usually coincide with seasonal peaks of enteroviral disease in the community. These outbreaks have been due mostly to echovirus 11 or group B coxsackievirus serotypes 1 to 5 and are associated with attack rates of up to 50 per cent.