Epidemiology of neonatal enterovirus infection.

During a typical enterovirus season in Rochester, New York, none of 666 neonates or 629 mothers were found to be excreting nonpolio enteroviruses within 1 day of delivery. No enteroviruses were isolated from weekly cultures of the 23 infants who died or remained hospitalized during the first month of life. After discharge, culture specimens were obtained in 586 infants at one to four weekly home visits until 1 month of age. The incidence of acquisition of nonpolio enterovirus infection was 12.8%, and the overall prevalence of enterovirus excretion was 5.3%. Risk of virus infection was associated only with lower socioeconomic status (P less than 0.0001) and lack of breast-feeding (P less than 0.0001). Four percent of all infants and 21% of infants in whom cultures for enterovirus were positive were readmitted to the hospital in the first month of life; 79% of infants with positive enterovirus cultures were asymptomatic. We conclude that enterovirus infection during the first month of life is very common in the late summer and early fall. Most infants are asymptomatic, but the risk of hospitalization is high. Breast-feeding may be associated with protection from infection.