The complete cycle of the human malaria parasite, consist principally of two stages namely:
Ø A period of development within mosquitoes when the infective spororozoites are formed in the blood of mosquitoes by union of male and female gametocytes. This stage is called the sexual stage.
Ø A period of infection in man. These are cycles which involve erythrocytic cycle and exoerythrocytic cycle. It is known as asexual stage. When mosquito bites an individual with malaria it then feeds on the blood. The male and female gametocytes of plasmodium in the human blood enter the mosquito’s stomach where they unite and multiply and form sporozoites which develop in 8 – 36 hours. Sporozoites enter the insect’s salivary glands and inject into another human during mosquito bites. Sporozoites quickly enter the new hosts liver remain there for 7 – 9 days and further developed to mosquitoes. Merozoites are then liberated into blood stream and parasitize the red blood cell.