MEDICALPARASITOLOGY課件.pptVIP

MEDICAL PARASITOLOGY 医学寄生虫学(Medical parasitology)  Medical parasitology，the study of animality pathogen动物性病原体 harming human health, is one of basic science of preventive medicine and clinical medicine. It studies the pathogenic parasites寄生虫 and their relationships to the hosts宿主 and environment. it consists of medical protozoology医学原虫学, medical helminthology医学蠕虫学 and medical entomology医学节肢动物学. WHO重点防治的寄生虫病种类 malaria (疟疾) schistosomiasis （血吸虫病） filariasis (丝虫病) leishmaniasis (利什曼病) trypanosomiasis （锥虫病） 流行概况（国内） Malaria 30万 Schistosomiasis 约70万(03年100万) Filariasis 近期被消灭 Leishmaniasis 300~400例/年 Hookworm disease2亿多(3930万) 我国寄生虫病流行情况 1.约5亿人感染土源性寄生虫(80%)，下降了约60%（与全国第一次普查） 2.食源性寄生虫病上升、并向城镇扩散，上升了75%（与第一次普查） 3.囊虫病在中、西、北部地区流行 4.弓形虫病呈扩大传播趋势 5.包虫病造成畜牧业巨大经济损失 一、寄生现象(Parasitism) (一)共生 （symbiosis） Any organism that spends a portion or all of its life intimately associated with another living organism of a different species is known as symbiont 共生者, and the relationship is designated as symbiosis. 根据两种生物间的利害关系，大致可分为共栖、互利共生和寄生三种现象。 1.共栖（commensalism) Commensalism共栖现象denotes an association that is beneficial to one partner and the neither benefited nor damaged to the other. （人 —— 结肠内阿米巴） 2.互利共生（mutualism) Mutualism互利共生 is seen when such associations are beneficial to both organisms. （白蚁 —— 鞭毛原虫） 3.寄生（parasitism） Parasitism寄生现象is a symbiotic relationship in which one animal, the host宿主, is to degree injured through the activities of the other, the parasite寄生虫.Parasite usually is the smaller of the two organisms. （蛔虫 —— 人） Parasite Obligate parasite An organism that cannot survive in any other manner is called an obligate parasite(专性寄生虫). Facultative parasite Facultative parasite(兼性寄生虫) is an organism that may exist in a free-living state or as a commensal and that, if opportunity presents itself, may become parasitic. It is implicit in this term that the organism does not of necessity have to be a parasite at any stage of its existe