Life cycle of
Cryptosporidium. Ingested sporulated oocysts release four sporozoites that invade host epithelial cells and develop into trophozoites, before undergoing asexual and sexual reproduction, resulting in the generation of both thin and think walled oocysts. Thin-walled oocysts auto-infect epithelial cells and thick-walled oocysts are excreted in the faeces of the host. Reproduced from .