Abstract
To find the situation of primary infection of human cytomegalovirus, the longitudinal virus isolation was attempted with healthy infants living at home, from birth to one year of age. The excretion of the virus detectable in mouth swabs was clearly demonstrated among infants between 5 and 9 months of age, at maximum 56 per cent of infants of 5 months. The incidence of isolation apparently diminished when infants reached to 10 to 12 months of age.
The results may suggest that the primary infection of cytomegalovirus occurs in approximately 50 per cent of healthy infants living at home, by 5 months of age. Then it is considered that these normal infants may become carrier of the virus persistently. Accordingly, acquired cytomegalovirus infection or pathogenicity of the virus should be discussed after due consideration of these findings. Finally, possibility of vertical transmission in the normal infants is discussed.
