抄録
The course of natural infection with measles virus was examined serologically and histopathologically in monkeys which were kept in routine quarantine. Giant cells of the Warthin-Finkeldey type were consistently detected in the lymph nodes biopsied one week after the serologically estimated time of natural infection, and they were considered to be caused by natural infection.
Histopathological responses to subcutaneous inoculations of various strains of measles virus were then compared in monkeys which were kept in strict isolation from natural infection. The wild virus consisting of either throat washings from measles patients or infected monkey tissue extract produced a large number of giant cells widely distributed in the lymphoid tissues of all the monkeys inoculated. On the contrary, attenuated vaccines and other laboratory strains did not produce giant cells in most of the monkeys inoculated except in few monkeys which had small number of giant cells only in a limited distribution. In spite of such a marked difference of pathological changes between the wild virus and the vaccine or laboratory strains, no definite correlation of the pathological changes with the virulence of measles virus could be elucidated since the several laboratory strains which were supposed to be unattenuated behaved apparently in a similar way as the attenuated vaccines.
