Host-Parasite Relationships in Echinococcosis

Abstract

Summary 1. White mice 48 days of age or younger at time of inoculation were highly susceptible to an initial infection with scolices of Echinococcus granulosus when the latter were given intraperitoneally. 2. Mice 71 days of age or older were relatively resistant to an initial infection under similar conditions. 3. Four mice which were unweaned at time of inoculation died on the 10th and 11th days postinfection. 4. The few cysts which developed in older mice were often larger than any which developed in younger counterparts. The possibility of an ecological “crowding effect” is suggested. 5. The difference in susceptibility to infection appeared to be related to the magnitude of the host's cellular response. 6. The development of hydratid cysts from scolices is described.