《医学寄生虫学：卫氏并殖吸虫》由会员分享，可在线阅读，更多相关《医学寄生虫学：卫氏并殖吸虫（30页珍藏版）》请在金锄头文库上搜索。
1、卫氏并殖吸虫卫氏并殖吸虫 Paragonimus westermaniBrief introductionCause of paragonimiasis, in carnivores, First known in 1878Subacute to chronic inflammatory disease of the lung.Paragonimiasis : zoonosisMorphologyMorphologyAdult wormAdult worm（1）Thick, reddish brown and ovoid (2) 10mm5mm 4mm (3) oral and ventral
2、 suckers : equal in size (4) two testes , present side-by-side at the posterior fourth of the body. (5) ovary: 5-6 lobes uterus (6) vitelline follicles卵黄腺卵黄腺 Live adultMorphologyMorphologyEgg100m55m golden brownasymmetrically ovoida thick and asymmetric shell with a distinct operculum. 1 ovum (卵卵细胞胞
3、 ) more than 10 vitelline cells(卵黄卵黄细胞胞) Life cycle Adult （Lungs of humans or animals） EggsMiracidiumSporocyst Redia (two generations)Cercaria Meta- cercariaCrustaceans including crabs, cray-fishes (溪蟹、蝲蛄蝲蛄) )淡水螺淡水螺A Cross-section of Paragonimus Sp in LungsMelania ( (川卷螺）川卷螺）Fresh water snail: Semis
4、ulcospira libertina（放逸短沟蜷）（放逸短沟蜷） 蜷科蜷科(Thiaridae) and 黑贝科黑贝科(Pleuroceridae)The first intermediate hostThe second intermediate host Fresh water Crab Fresh water crayfish=crawdad (Cambaroides spp)溪蟹溪蟹lHuman lCarnivores: dog, cat, tiger, leopardDefinitive hostMetacercariae 囊蚴囊蚴Spherical , 300400 m, Two
5、 layers of transparent walls.Key points of life cycleSite of inhabitation: lungs Infective stage: metacercariaInfective mode: ingestion of crabs and crayfish with metacercariaeIntermediate hosts: 1st int. host : Melania snail(川卷螺川卷螺); 2nd int. host: crab and crayfish(溪蟹、蝲蛄溪蟹、蝲蛄)Reservoir hosts: tige
6、r, lion, wolf, fox, dog, leopard, cat Paratenic host: boar(wild pig)Life span: 4-5 yearsPathogenesis Acute infection: induced by larval invasion and migration ( intestine, liver and lung)Chronic infection: abscess, cyst, fibro-scar1.Abscess stage脓肿期脓肿期2.Cystic stage囊肿期囊肿期3.Fibrous scar stage纤维疤痕期纤维疤
7、痕期Allergic reaction: fever, urticaria (荨麻疹荨麻疹), IgEPathogenesisEncapsulated cyst in lungCross section of lung from patient infected with P.westermani囊肿期囊肿期Migration 肠肠 -腹腔腹腔-胸腔胸腔-肺肺腹壁腹壁-皮下皮下-肠系膜（肝）肠系膜（肝）纵膈纵膈-破裂孔破裂孔-脑脑Manifestations of paragonimiasisAsymptomatic paragonimiasisThorax lung paragonimias
8、is: 胸肺型胸肺型 resemble pulmonary tuberculosis(结核结核)Cerebral paragonimiasis:脑脊髓型脑脊髓型 resembles cerebral cysticercosis(脑囊虫病脑囊虫病). epilepsy(癫痫癫痫), hemiplegia(偏瘫偏瘫), monoplegia(单瘫单瘫),aphasia(失语失语), visual disturbanceAbdominal paragonimiasis:腹型腹型abdominal pain，diarrhea or dysentery with blood, mucus and egg
9、s in feces. Subcutaneous paragonimiasis:皮下包块型皮下包块型 wandering and painless subcutaneous nodules. Thorax lung paragonimiasis 胸肺型胸肺型low fever, loss of appetite, night sweating, chest pain, loss of weight, chronic cough and rusty-brown sputum Cerebral paragonimiasis 脑脊髓型脑脊髓型headachefeverNauseavisual dis
10、turbances convulsive seizuresHand distortioncystsSubcutaneous paragonimiasis皮下包块型皮下包块型DiagnosisHistoryParasitological examination : sputum & feces Immunodiagnostic test: IDT皮内试验皮内试验 ELISA for special antibodies dot-ELISA X-ray /CT Eosinophilia 80 Far East, Africa and South AmericaWorld wide distribu
11、tion Epidemiologycrayfish endemic area蝲蛄流行区蝲蛄流行区crab endemic area溪蟹流行区溪蟹流行区EpidemiologyIn China :23 provinces and autonomous regions.Epidemiology1.Definitive hosts: humans; Reservoir host： tiger, dog, cat 2.Paratenic host: boar(wild pig)3.Zoonosis（人（人兽兽共患病）共患病）4.First intermediate hosts; Second inte
12、rmediate hosts5.Routes of infection : u1) raw crab or crayfish containing metacercariae u2)meat of a paratenic host containing immature flukesu3) water containing metacercariae囊蚴囊蚴 or cercariae尾蚴尾蚴Reservoir hostsome endemic: dogs, catssome endemic: wild animalsDrunk crabMontanic rivuletEpidemiologyP
13、revention and controlHealth education : eating habitsUse of molluscacides灭螺剂灭螺剂Chemotherapy Praziquantel：75mg/(kg/d) 2天天Bithionol(硫双二氯酚）硫双二氯酚） Pagumogonimus skrjabini 斯氏狸殖吸虫斯氏狸殖吸虫Cutaneous paragonimiasisLife cycle resembles that of P. westermaniDefinitive hosts: Paguma(果子狸果子狸), cats, dogs etcHuman:
14、non-normal hostMost of larvae cant develop to mature wormMigration of larvae cause pathological changesImmunological test & biopsyP. weatermaniP. SkrjabiniDHHUMAN and animalswild animals1stIHSemisulvospira libertinaTricula humida (拟钉螺）拟钉螺）2ndIHCrabscrayfishescertain crabs (石蟹）石蟹）PathogenesisLung/Cer
15、ebral/liver paragonimiasis,Subcutaneous or visceral larva migransDiagnosiseggs,immunological detection; biopsyimmunological detection; biopsyP. westermaniC. sinesis F. buskiDefinitive hosthumanhumanhumanReservoir hostTiger, dog .Dog, catpigParatenic hostBoarnonoeggSputum/feces Feces FecesMiracidium Water Snail Water Sporocyst snailSnail Snail Rediae snail motherSnail Snail daughterSnail Snail cercariaeSnail/waterMetacercariae Crab/crayfishFish/shrimpwaterplantsLarvaeMigration nonoAdult Lung，Bile ductsIntestine Ectopic parasitism yesnoNo
