人體寄生蟲學(xué)課件：總論（2013級本雙語）

PARASITOLOGYMedicalINTRODUCTIONTOMEDICALPARASITOLOGY

MaintopicsParasitism,TypeofParasiteandHostLifecycleandInfectivestageTheRelationshipbetweenParasiteandHostFeatureofparasiticinfectionandparasitosisEpidemiologyofParasitosis

Abranchofthemedicalsciences.IsthesciencetostudytheparasiteandparasiticdiseasesAsciencetostudytheparasitism.Belongtonosetiology(病原生物學(xué)).Abasiccoursefortheclinicandphylaxiology(預(yù)防醫(yī)學(xué))MEDICAL(HUMAN)PARASITOLOGYPrefacemedicalhelminthology醫(yī)學(xué)蠕蟲學(xué)medicalarthropodology醫(yī)學(xué)節(jié)肢動物學(xué)medicalprotozoology醫(yī)學(xué)原蟲學(xué)MEDICALPARASITOLOGYWhydowewanttostudyhumanparasit-ology?HARMFULNESSOFPARASITESTOHUMANBEINGSTenimportanttropicaldiseasesdefinedbyWHO:1975-1Malaria(瘧疾)2Schistosomiasis(血吸蟲病)3Filariasis(絲蟲病,淋巴絲蟲和盤尾絲蟲)4Leishmaniasis(黑熱病)5Trypanosomiasis(錐蟲病,非州錐蟲病和美州錐蟲病)6Leprosy(麻風(fēng)病)2000-7Tuberculosis(結(jié)核病)8Denguefever(登革熱)瘧疾血吸蟲病絲蟲病黑熱病鉤蟲病我國五大寄生蟲病瘧疾血吸蟲病絲蟲病黑熱病鉤蟲病

INCHINA

meaninfectiverate(%)(2004)(1990)Ascaris12.7247.3Trichuris4.6319.3Hookworm6.1217.2informationofparasiticinfectionsinChina

parasites:56species，

totalinfectiverateofhelminths21.74％

Theproblemandchallengewearefacedwithatpresent1.土源性線蟲（鉤蟲、鞭蟲、蛔蟲、蟯蟲）雖然得到明顯控制，但仍然是主要問題2.食源性寄生蟲病急劇上升3.機(jī)會性寄生蟲、性傳播寄生蟲感染率增加4.新現(xiàn)寄生蟲不斷出現(xiàn)哇!寄生蟲的危害如此之大!不說不知道,說了嚇一跳耶!老師,這寄生蟲是何許東西?好問題,且聽我慢慢道來PARASITISMPARASITE&HOST1Fromviewpointsofbenefitandharm,thereare3kindofrelationships1.Commensalism（片利共生）:

anassociationwhichisbenificialtoonepartnerandnoharmtotheother.benefitNoharm&nobenefitTherelationshipsbetweenanimalsthatlivetogetherParasitism（寄生）:

Onepartnerderivesbenefit.Anotherisinjured.Parasitisminvolvestwofactors:parasiteandhostMutualism（互利共生）:

reciprocalbenefitbetweenthetwoorganisims.benefitbenefitbenefitBeinjuredparasitehostAmongthepartnersintheparasitism,theonewhichbenefitsfromtheotherisaparasite,whiletheonewhichisharmedbytheparasiteisahost.PARASITEandHOSTCLASSIFICATIONOFPARASITES

1.Basingonthebiologicaltaxonomy(1)Medicalprotozoa(2)Medicalhelminths(3)Medicalarthropods(1).Obligativeparasites:專性寄生蟲(2).Facultativeparasites:兼性寄生蟲(3).Endoparasite:體內(nèi)寄生蟲(4).Ectoparasite:

體外寄生蟲.(5).Opportunisticparasite:機(jī)會致病寄生蟲2.BasingontherelationshipbetweenparasiteandhostIntermediate

host(中間宿主):thoseprovidethelivingoflarvaeofhelminthorasexualstagesofaprotozoan.FirstandsecondintermediatehostReservoirhost

(保蟲宿主):thoseanimalhostsofhumanparasitesinwhichparasitesarekeptaliveforlongperiodoftimewithfrequentexcretionoftheeggsorpathogens(serve

asasourceofinfectionforhumans).

Definitivehost(終宿主):thoseprovidethelivingofadulthelminthorsexualstageofaprotozoan.TypesofhostsTransportorparatenichost(轉(zhuǎn)續(xù)宿主):LIFECYCLEOFPARASITES2Thewholebiologicalcourseofgrowth,developmentandreproductionofaparasite,includingenvironmentconditionsitneeds.Therearetwotypesoflifecycle:directandindirect.LifecycleDirecttypelifecycleDon’tneedintermediatehostIndirecttypelifecycleNeedintermediatehostThestagethatisabletoinfecthumanbodyinlifecycle.Iermediatehost.diagnosticstage.

infectivestage&transmittingpath.Lifecycleisacoreinparasitology.5.THERELATIONSHIPBETWEENPARASITEANDHOST3A.Uptakingnutrition（奪取營養(yǎng)物質(zhì)）B.Physicaltrauma（機(jī)械性損傷）C.Chemical(toxins)andallergiceffects（化學(xué)性和免疫病理作用）:a)Lyticnecrosis:Enzymesb)Stimulationofhosttissuereaction:c)causinghypersensitivity1.EffectsofParasitesonHost

2.Effectsofthehostonparasiteimmunity(refertoimmunology)Resultsfromreactionbetweenparasiteandhost1Parasitewillbeeliminated2Keepbalance(suppressiveinfection,carrier)3Parasitosis4CharacteristicofParasiticInfectionandParasitosisdefinitionParasiticinfection寄生蟲感染Parasitosis寄生蟲病carrier,inapparentinfection帶蟲者,隱性感染Polyparasitism多蟲寄生Larvamigrans幼蟲移行

ectopicparasitism異位寄生Parasiticzoonosis人獸共患性寄生蟲病Opportunisticpathogenesis機(jī)會致病CharacteristicofparasiticinfectionImmunityofparasiticinfection5featureComplicationofantigens(structure,stage,metabolism)2.Non-sterilizingimmunityiscommon:premunition(帶蟲免疫),concomitantimmunity(伴隨免疫)3.Re-infectionoccursoften4.Immuneevasion(免疫逃避)5.

Eosinophilia

andIgElevelincreasewithinfectionofhelminthesEPIDEMIOLOGYOFPARASITOSIS6routeoftransmissionSourceofinfectionSubjectsofindividuals(orsusceptiblepopulation)parasite1.BasicconditioninparasiticepidemiologyA.patientsB.carrierC.reservoirhost

(1)Sourceofinfection(2)RouteofTransmissionA.Wayoftransmission(傳播方式）Water-borne經(jīng)水Food-borne經(jīng)食物soil–borne經(jīng)土壤Arthropod-borne經(jīng)節(jié)肢動物Person-to-personcontact與人體接觸Air-borne經(jīng)空氣B.Portalofentry(侵入途徑）a.Oralroute經(jīng)口b.Skinandmucousmembraneroute經(jīng)皮膚黏膜c.Arthropodbite經(jīng)節(jié)肢動物叮咬d.Person-to-personcontact經(jīng)接觸Transplacentalpenetration經(jīng)胎盤Bloodtransfusion經(jīng)輸血Inhalation吸入

(3)SubjectsofindividualsorSusceptiblepopulation

Humansoranimalswhoareweaklyordefecti-velyresistanttocertainparasites.2.MajorfactorsinfluencingtheepidemicofparasiticdiseaesNaturalfactorweather,geographyetc.(2)Biologicalfactordistributionofintermediatehosts(2)SocialfactorsPolitical,economic,cultureandpersonalbehavioretc.3.Epidemiologicalfeatureofparasitosis

Endemicepidemic(地方性):

Theparasiticinfectionsusuallyfocusoncertainareas.

Reason:A.WeatherconditionB.DistributionofintermediatehostC.Resident’scustom(eatingorotheractivities)(2)Seasonalepidemic(季節(jié)性):

Epidemicofparasitosisisoftenseasonal.Infectiverateofsomeparasiteschangeinseasons.Reason:Temperature,rainingetc.caninfluencethegrowthofparasitesandactivityofvectors.(3)Naturalfocalepidemic(自然疫源性):

Someforestanddesertareaswheretheparasitic

zoonosescantransmitamongwildvertebrate,arecallednaturalendemicfoci.Ifsomeoneenteredthearea,heorshewouldgettheparasitic