EN
Plasmodium chabaudi, a rodent malaria parasite with a synchronous asexual cycle in the blood, depending on the host’s circadian rhythm, was desynchronized by modifying its normal timing: blood taken from a donor mouse in the morning was kept 8 h at +4°C and inoculated in the evening into naive mice. When the infection had become asynchronous (from day 4 to day 7) mice were treated with a single dose of chloroquine. The efficacy of chloroquine was lower in mice with an asynchronous infection than in the control mice with a normally synchronous infection.