Trophozoites feed on hemoglobin and can be controlled at this stage with the anti-malarial drugs quinine or chloroquine . These drugs work by crosslinking the DNA double helix and are selectively toxic for the microbe because human rbcs are not nucleated. If our mature blood cells don't contain DNA, and the drug is taken up by rbcs, then only the microbial DNA will be effected and our cells unharmed If not treated, the trophozoites change back into lots of merozoites until the merozoites are so numerous that they burst the rbc. All the debris of the burst rbcs causes an inflammatory response and releases pyrogens . Every merozoite released will find another rbc to begin this cycle of destruction of more rbcs.
Malaria results in anemia, fatigue, malaise etc.
This rbc stage can go on for years without killing you. The disease could stop here with this patient carrying the gametophytes. But usually another uninfected female Anopheles mosquito bites the victim and sucks into her blood meal at least one male and one female gametophyte. The gametophytes mate in the GI tract of the mosquito sexually and produce a zygote which implants in the mosquito stomach and divides asexually to make lots of sporozoites. These sporozoites migrate to the salivary glands of the mosquito and start the cycle again when this infected mosquito bites an uninfected human being.