The chemosensitivity of the rodent malarias--relationships with the biology of merozoites.

According to the hypothesis proposed by Landau, Cambie & Chabaud (1990, Annalees de Parasitologie Humaine et Comparée 65: 101-103), the chemoresistance of malaria is related to the selection of strains with latent merozoites, the latter being capable of penetrating into red blood cells at other times than that of the time of schizogony and reinfect the host with as much of a delay as several days. They determine an asynchronism of the schizogonic rhythm and, being so far resistant to all known medication, should induce, at least to some extent, a chemoresistance. Consequently, there are three factors linked to merozoites: latency, asynchronism and chemoresistance. The relationship between asynchronism and latency of merozoites has been demonstrated previously (Cambie, Landau & Chabaud, 1990, Compte Rendus de l'Academie des Sciences de Paris 310: 183-188.). In the present work it was shown that the two classifications of strains, first in order of increasing chloroquine resistance, second in order of increasing degree of persistance of merozoites in the blood, are almost identical for the 10 strains, subspecies or species of Plasmodium considered. The relationship between latency of merozoites and chemoresistance appears to have been demonstrated.