Attention has been called in a previous paper (1) to certain characteristics of the infections resulting from artificial (by trophozoites) inoculation with Plasmodium vivax, as contrasted with natural (by sporozoites) inoculation, which indicate certain fundamental differences. While many of the characteristics of naturally induced vivax malaria observed in our service have been previously described (2, 3, 4, 5) it appears desirable, in view of these differences, to give a general account of our experience with the artificially induced infection.
While the greater part of our routine inoculations are effected naturally, a certain number are also effected artificially. The latter method is preferred in testing immunity, and also for conservation and propagation of infrequently used strains. The artificial inoculations are effected by the intravenous inoculation of the recipient with varying quantities, not exceeding 10 cc., of citrated whole blood, just withdrawn from the infected donor.
I wish to express my appreciation of assistance in the statistical computations from Miss Pauline A. Mead.