Latency of Plasmodium merozoites and drug-resistance. A review

The authors summarize the results of recent work evidencing the existence of latent merozoites during the course of the erythrocytic cycle of the rodent Plasmodia. These merozoites, unlike the majority of merozoites released at schizogony, do not penetrate immediately into the erythrocytes and remain latent for a variable length of time. The merozoites of each of the species or subspecies show marked peculiarities which are responsible for the characteristics of their cycle. The presence of latent merozoites free in the blood, the asynchronous development, and the resistance to chloroquine, are three closely related factors. Knowing that the merozoite is so far drug resistant, and that latent merozoites can maintain the infection for any length of time, it appears important to take into account these purely biological data, when studying the drug resistance of the human falciparum malaria.