Further studies on neonatal rotavirus infections.

Forty newborn babies who were shown to be excreting rotaviruses within a few days of birth were tested daily for one month. Most were found to excrete virus for only a short period of time. In 48% of babies, virus was found on one day only, in 25% it was present for two days, and in 10% for three days. Most of these infections did not appear to confer lasting immunity. Only 21% of young children who excreted virus as neonates had detectable circulating complement-fixing antibodies when eight to eighteen months old. A survey of newborn babies showed that 89% of babies possessed the antibody, but, by the age of four to six months, the antibody was present only in 7%. This supports the view that infected neonates fail to develop circulating complement-fixing antibodies. Infection rates did not differ significantly between breast-fed and bottle-fed babies. Likewise, maternal antibody levels could not be shown to have any effect on infection. No rotavirus particles were found in breast milk.