人体寄生虫学复习总结.pptx

教学及考试形式教学及考试形式1.教师主讲与学生参与讨论、演讲相结合 （可23人/组,每组学生参与1-2次讨论，以组为单位进行记分）2.课程成绩的组成：平时 理论考试 实验 2080实验课安排实验课安排 时间：周三下午（双周）（第 2,4,6,8,10周，共5次）第1次实验，9月16日（周三）下午上课地点：病原生物学实验室（东1号楼3楼东）带上实验报告纸（8张，订起来）穿实验服 按要求入座并固定下来（不要迟到）教学辅助1.精品课程网站：http:/2.教学大纲3.教学参考书4.其他：常用网址：1.http:/www.dpd.cdc.gov/dpdx/Default.htm 2.http:/www.cdfound.to.it/HTML/atlas.htm Human Parasitology(Medical Parasitology)Medical Parasitology is a branch of medical science dealing with parasites living in and on the body of humans and with aspects of this host-parasite relationships having medical significance.Bridge course between basic medicine and clinical medicine认识寄生虫及寄生虫病诊治寄生虫病预防寄生虫病Why do we study parasites?1.Medical importance Is a lion a parasite?Is a mosquito a parasite?Who is a parasite?Protozoa 原虫原虫Helminths 蠕虫蠕虫Arthropods 节肢动物节肢动物 Three major groupsIn this course we will concentrate on:The detriments of parasites to humans Recent estimates of prevalence of parasites in the world are:Ascaris 1.5billion Hookworms 1.3 billion Whipworms 1 billionFilarial worms 657 million Malaria 500 million 1.1568 m(mortality)Schistosomes 270million Amebiasis 50 millionTaeniad tapeworms 50 million Clonorchis 20 million Chagas Disease 15 million disease burden (WHO,2000-2004)disease burden (WHO,2000-2004)malaria 42.7386 million malaria 42.7386 million leishmania 2.066 million leishmania 2.066 millionDALYs(disability-adjusted life years)失能调整生命年The sum of years of potential life lost due to prematuremortality and the years of productive life lost due to disability.Year 1975 Year 1975Malaria 疟疾疟疾Schistosomiasis 血吸虫病血吸虫病Filariasis 丝虫病丝虫病Leishmaniasis 利什曼病利什曼病Trypanosomiasis 锥虫病锥虫病(麻风麻风 leprosy)Year 2000 Year 2000疟疾疟疾 malaria血吸虫病血吸虫病 schistosomiasis丝虫病丝虫病 filariasis 淋巴丝虫病淋巴丝虫病 lymphatic filariasis 盘尾丝虫病盘尾丝虫病 onchocerciasis利什曼病利什曼病 leishmaniasis锥虫病锥虫病 trypanosomiasis 非洲锥虫病非洲锥虫病 美洲锥虫病美洲锥虫病 麻风麻风 leprosy结核病结核病 tuberculosis登革热登革热 dengue feverTropical Diseases-Forgotten People,Forgotten DiseasesIncluding several diseases,which affect one in six people globally,are neglected by everybody-by the pharmaceutical industry,by mainstream global health efforts and by the media.被忽视的热带病被忽视的热带病 (Neglected Tropical Diseases)一类盛行千年，危害严重，多见于极端贫困地 区的慢性传染性疾病malaria 疟疾schistosomiasis日本血吸虫病 elephantiasis 淋巴丝虫病 (象皮肿)river blindness(盘尾丝虫病,河盲症)leishmaniasis 利 什 曼 病Chagas disease 美洲锥虫病美洲锥虫病 sleeping sickness sleeping sickness(非洲锥虫病非洲锥虫病,睡眠病睡眠病)Current situation of parasitic diseases in China 1950s 2000sMalaria 3107 3104Schistosomiasis 1.16107 8.4105Lymphatic filariasis 3107 eliminated Leishmaniasis 5.3105 eliminatedHookworm disease 1.94108(1988-92)3.93107(200104)Parasitic diseases importing from other countriesIntestinal helminths (1.29108)Food-borne parasitosisEmerging parasitic diseasesNeoemerging Reemerging 2004年第二次寄调食物源性寄生虫病2.Economic importance2.Economic importanceWhy do we study parasites?3.Veterinary importance3.Veterinary importance4.Biological importance 4.Biological importance 思考：思考：1.寄生虫（寄生虫病）的研究发展史。寄生虫（寄生虫病）的研究发展史。2.人类能最终战胜寄生虫病吗？人类能最终战胜寄生虫病吗？（寄生虫病能消灭吗？）（寄生虫病能消灭吗？）3.Some types of parasitic infections are increasing,please discuss in detail.Evolution of parasitism：Free living Symbiosis（共生）biology of parasitesbiology of parasites commensalisms 共栖共栖mutualism 互利共生互利共生parasitism 寄生CommensalismBeneficial to one partner and at least not disadvantageous to the other （One partner benefits but the other is not hurt.）鮣鱼鮣鱼returnMutualismbeneficial to both organisms(Both partners benefit)Sea anemones /hermit crabsTermite /flagellated protozoanreturnA symbiotic relationship in which one animal(the host)is to some degree injured through the activities of the other animal(the parasite).In other words,One partner(the parasite)harms or lives on the expense of the other（the host）Parasitism-a way of lifeParasites are smart!Parasite（寄生物，寄生虫）:An organism which is dependent on another organism for its survival Host（宿主）:An organism which harbors the parasite（and is usually larger than the parasite）Definition of parasite,host and parasitismMorphological adaptations 2.Specialized attachment organs been developed(hooks,suckers)3.Some organs lost or reducedSome organs strengthened(reproductive system)1.Adaptation of bodily form Adaptations to Parasitism Physiological adaptations Metabolic changes 代谢改变 Specialized mechanisms for affecting entrance into the body or tissue(elaboration of enzymes)侵入机制特化 High reproductive capacity for maintaining the species 繁殖能力增强 Life cycle and the classification of the host and parasitelife cycle life cycle 生活史The whole process of the growing,development and reproduction of parasite within and outside the host.(寄生虫完成一代的生长、发育与繁殖的整个过程。)Two common phases:the route a parasite follows inside the body The route a parasite follows outside of the body Three common components:a mode of transmission(discuss later)an infective stage a diagnostic stage the stage of development of parasites which can invade host and continue further development within the host.感染期 infective stage infective stage（感染阶段）（感染阶段）生活史过程中对人体具有感染能力(侵入人体并继续发育）的阶段Direct life cycle:In which the parasite is passed from host to the next through the contaminated food or water,it doesnt need intermediate host.Indirect life cycle:Intermediate host is necessary in the style of life cycle Kinds of life cyclesEx：Enterobius vermicularis Ex：Taenia solium Definitive host:Host(终宿主终宿主 definitive host：成虫或有性生殖阶段寄生的宿主。成虫或有性生殖阶段寄生的宿主。)The one in which the parasite reaches sexual maturity or undergoes sexual reproduction.(harbours the adult or sexual reproduction stages of the parasite)In which only larval development or asexual reproduction occurs or both(中间宿主中间宿主 intermediate host：幼虫或无性生殖阶段寄生的宿主。幼虫或无性生殖阶段寄生的宿主。)Intermediate host:Reservoir host:The parasite can be transmitted to humans(zoonosis)or domestic animals as additional sources of human infection某些寄生虫既可寄生人体，也可寄生某些脊椎动物，并可传播给人某些寄生虫既可寄生人体，也可寄生某些脊椎动物，并可传播给人,在在流行病学称这些动物为保虫宿主。流行病学称这些动物为保虫宿主。Domestic or wild animals that harbors the adult or sexual stage of certain humans parasite.保虫宿主保虫宿主 （储蓄宿主）：储蓄宿主）：Paratenic host(transport host):转续宿主转续宿主某些寄生虫的幼虫侵入非正常终宿主某些寄生虫的幼虫侵入非正常终宿主,不能发育为成虫不能发育为成虫,长期保持幼虫长期保持幼虫状态状态,只有当该幼虫有机会侵入正常终宿主体内时只有当该幼虫有机会侵入正常终宿主体内时,才能发育为成虫才能发育为成虫,这这种非正常宿主称为转续宿主。种非正常宿主称为转续宿主。An abnormal host(not suitable for parasite development),when a parasite enters,it do not undergo any development but continues to stay alive and be infective to a normal host（cause disease).facultative parasite 兼性寄生虫兼性寄生虫A parasite can live both in or on the host as well as in a free-living form parasitic and free living generations can alternate depending on environmental conditionsParasiteAccording to characteristic of parasites:Obligatory(obligate)parasite 专性寄生虫专性寄生虫A parasite can live only in a association with a host or an organism,can not survive without a host Accidental parasite 偶然性寄生虫偶然性寄生虫按宿主选择性permanent parasites 永久性寄生虫永久性寄生虫temporary parasite 暂时性寄生虫暂时性寄生虫 some animals invading the host temporary only for bloodsucking,such as mosquitoes,ticks,etc.Ectoparasite 体外寄生虫体外寄生虫 Exist on the body surfaceEndoparasite 体内寄生虫体内寄生虫 Parasites living within(inside)the host body 按寄生时间按寄生部位Opportunistic parasite Some parasites,such as Toxoplasma gondii,cryptosporidium parvum,pneumocystis jiroveci,etc,only induce unapparent infection in the host with normal immune competency,but can lead to severe disease even death in the person suffered with AIDS or other immune deficiency conditions.immunocompromised host（免疫受累宿主）（免疫受累宿主）机会致病寄生虫：如弓形虫、隐孢子虫、肺孢子虫等，在宿主体内通常处于隐性感染状态，在宿主免疫功能降低时，出现异常增殖或致病力增强。Nourishment and metabolism of the parasites(omit)Asexual reproduction 无性生殖sexual reproduction 有性生殖 Alternation of generation (世代交替世代交替)A reproduction mode of some protozoon and helminthic parasites characterized by the alternation of generations with asexual and sexual reproduction in their life cycle.reproduction mode of parasitesNomination of the parasiteParasitology historically covers a diverse collection of metazoan and unicellular organisms Kingdom 界 Phylum 门 Class 纲 Order 目 Family 科 Genus 属 Species 种Binominal system is applied for parasitesGenus name +species name With a capital with a small Initial letter initial letterspecific name of parasitesAll in latinied language with italic or underlinedSchistosoma japonicum Abbreviation:S.japonicum （Schistosoma japonicum Abbreviation:S.japonicum）Parasite-host relationship3.Poisoning and ImmunopathologyEffects of the parasite on the host1.Nutrition robbing2.Mechanical injury-Natural immunity(nonspecific immunity)Effects of the host on the parasiteBarrier:Skin/Mucous membrance/Placenta.Fluid(Acid):Phagocytosis:But not very strong!Immune evasion hypersensitivity-Acquired immunity(specific immunity)Effects of the host on the parasiteSterilizing immunity 消除性免疫Wipe out the parasites completely,meanwhile get a long-term specific resistance to re-infection.Non-sterilizing immunity 非消除性免疫(Common!)Wipe out most of the parasites,but not completely.No parasite,no immunity!premunition 带虫免疫 concomitant immunity 伴随免疫The characteristics of parasitic infections and parasitosis parasitic infections 寄生虫感染寄生虫感染:establishment of the parasite in its hostparasitic diseases (parasitosis寄生虫病寄生虫病):Clinical manifestation of the parasitic infection which shows the active presence and production of the parasite causing damage in the host.Carrier 带虫者:a person who is infected with a certain parasite without displaying any clinical signs or symptoms but can serve as a source of parasitic infection.Suppressive infection 隐性感染 without any clinical signs or symptoms can not be detected by usual methods may or may not as a source of parasitic infection chronic infection 慢性感染慢性感染Polyparasitism 多寄生现象多寄生现象larva migrans 幼虫移行症 Some juveniles of animal helminths invade human if human is not their adapted host,the juveniles can not develop to adults but migrate in the body of human and cause lesions to tissues or organs.为什么会出现多寄生？多寄生后会出现什么结果？ectopic parasitism 异位寄生异位寄生 Generally,human parasite will dwell in a definitive site in human body,but in some cases,the parasite lodge in different sites,this phenomena was called.Epidemiological factors and principle of control Basic rules for the prevalence of parasitic diseasesPatientscarriersSources of infectionanimalsHumans Routes of transmissionSusceptible population传染源传播途径易感人群 Through food Through water Through soil Through air Through blood-sucking arthropod Through direct contactRoutes of transmission1.Pre-oral ingestion(through mouth)EX，consuming contaminated food or water hand-to-mouth contamination(fecal-oral)2.Pre-cutaneous(via skin)or other surface Ex,eye contact with infected swimming water 3.Pre-respiratory(through inhalation)4.Through direct contact（sexual transmission）5.Through thansplacental infection 6.Via blood infusion 7.Via organ transplantation 8.Via self infection 9.via the bites of arthropod vectors(via a blood meal)Routes of infection (invade other persons)感染方式 Influencing Factors for the prevalence of parasitic diseases1.Natural factors2.Biological factors3.Social factors影响因素Characterization of the prevalence of parasitic diseases Endemic epidemic 地方性流行地方性流行Seasonal prevalence 季节性流行季节性流行Natural focal epidemic 自然疫源性流行自然疫源性流行Natural endemic focus(自然疫源地自然疫源地)：some forest and desert areas where the parasitic zoonoses can transmit among wild vertebrate 流行特点在人和动物之间自然传播着的寄生虫病。Parasitic zoonoses 人兽共患寄生虫病:these are the parasitic infections which are naturally transmitted among the vertebrate animals and man.Treatment of patients and carriers 控制传染源 destruction or control of reservoir host Blockade of the route of transmission 切断传播途径 Protection of the susceptible population 保护易感者 (personal prophylaxis)Chemoprophylaxis,vaccines,other preventive measuresPrinciples of controlDiagnosis of parasitic diseases1.病原诊断（最可靠的检查方法）从病人的血液、组织液、排泄物、分泌物或活体组织中检出寄生虫的某一发育虫期。缺点：检出率较低，需反复筛查以免漏诊。2.免疫学诊断 皮内试验 抗体的检测 （循环）抗原的检测 具体方法学：IHA，ELISA，IFA，等3.分子生物学及其他高技术、新方法1.PCR技术2.核酸杂交技术3.免疫印迹技术等等