疟原虫弓形虫_1课件.ppt

Infection of plasmodium cause malaria . Malaria is by far the world’s most important tropical parasitic disease, and kills more people than any other communicable disease except tuberculosis. According to the WHO report, malaria kills one child every 30 seconds. Malaria is a public health problem today in more than 90 countries; 300-500 million clinical cases each year; more than 90% cases are in sub- saharan Africa Mortality due to malaria case is estimated to be over 1 million death each year. Four Plasmodium species are responsible for human malaria : Plasmodium vivax( 间日疟原虫） P.malariae （三日疟原虫） P.ovale （卵形疟原虫） P.falciparum （恶性疟原虫） Human is the intermediate host, the asexual reproduction occur in liver and RBCs of the human host; Mosquito is the final host, the sexual reproduction takes place in the stomach of mosquito. Asexual reproduction in man Development in liver (exo-erythrocytic stage) Development in RBCs (erythrocytic stage) Sexual and asexual reproduction in mosquito    Conclusion: Definitive host: Mosquito Intermediate host: Human Infective form: sporozoite (子孢子) Parasiting residence: mainly RBCs Infective way: biting by mosquito , blood transfusion. Duffy血型（-）的西非人对P.v有抵抗力 镰状红细胞贫血（HbS）、红细胞缺乏 G6PD对P.f有抵抗力 1908年法国学者在刚地梳趾鼠的肝脾单核 细胞内发,因其滋养体呈弓形,故名为弓形虫. 1923年捷克眼科医师发现人类首例弓形虫病患儿. 机会致病性原虫(opportunistic protozoan), 引起弓形虫病(toxoplasmosis). 先天性感染引起胎儿畸形、流产等,与优生优育密切相关. The asexual cycle in intermediate host （human and rodents ） The sexual cycle in the definitive host (cats) The sexual cycle in the definitive host Cats gets infected by ingestion of cysts in flesh. Sporozoites , bradyzoites , tachyzoites are released from oocysts , cysts and pseudocysts respectively. Those organisms invade epithelial cells of the small intestine where they undergo an asexual followed by a sexual cycle and then form oocysts, which are excreted.? The asexual cycle in intermediate host ingestion of undercooked infected meat containing Toxopla