Cellular viraemia in babies infected with rubella virus before birth.

Chronic viraemia has been detected in 10 out of 12 rubella syndrome babies at periods ranging from 1 to 196 days. The virus was found to be associated with leucocytes, and it is assumed that removal of neutralizing antibody is the most likely explanation for the high success rate in detecting viraemia. The findings are discussed in relation to diagnosis by virus isolation, to pathogenesis, and to the possible significance in explaining the failure of the foetus to develop a tolerance to rubella virus. Several published reports of viraemia in the acute exanthematous disease are contrasted with the less frequent reports of viraemia in the chronic disease of early postnatal life.