[Virological studies of the virus shedding pattern of natural measles]

Using a novel, highly sensitive cell culture system, B95a cells, I investigated the virus shedding of measles virus (MV) of 47 cases with natural measles. MV was isolated from both peripheral blood leukocytes and respiratory secretions up to 6 days from the onset of the rash. By fractionation of blood, MV was isolated from lymphocytes and monocytes up to 6 days from the onset of the rash, however it disappeared rapidly within 48 hours from the plasma. The duration of positive MV isolation depends on the duration of fever, i.e. infectious MV could not be recovered beyond the 24 hours after the alleviation of fever. The data suggest that in natural measles, infectious MV is shed for a longer period than previously believed. The role of infection of monocyte in the pathogenesis of measles is also suggested.