Life cyle of Plasmodium spp.

 
     
  The malaria parasite life cycle involves two hosts.  During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host  .  Sporozoites infect liver cells  and mature into schizonts  , which rupture and release merozoites  .  (Of note, in P. vivax and P. ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks, or even years later.)  After this initial replication in the liver (exo-erythrocytic schizogony  ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony  ).  Merozoites infect red blood cells  .  The ring stage trophozoites mature into schizonts, which rupture releasing merozoites  .  Some parasites differentiate into sexual erythrocytic stages (gametocytes)  .  Blood stage parasites are responsible for the clinical manifestations of the disease. 

The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal  .  The parasites’ multiplication in the mosquito is known as the sporogonic cycle  .  While in the mosquito's stomach, the microgametes penetrate the macrogametes generating zygotes  .  The zygotes in turn become motile and elongated (ookinetes)  which invade the midgut wall of the mosquito where they develop into oocysts  .  The oocysts grow, rupture, and release sporozoites  , which make their way to the mosquito's salivary glands.  Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle