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1、 ( ( Blood Blood fluke )fluke )2024/7/281 Schistosome2024/7/2822024/7/2832024/7/2842024/7/285Six species of schistosome: Schistosoma japonicum Schistosoma haematobium Schistosoma mansoni S. intercalatum S. mekongi S. malayiSchistosoma japonicum: the Oriental blood fluke is confined to the Far EastSc
2、histosoma masoni:occurs: extensive areas of Africa and in the Arabian peninsula and MalagasySchistosoma haematobium: was apparently the Nile Valley, Africa, and so on.Schistosoma Mekongi: from the Mekong River basin in shouthern Laos and CambodiaSchistosoma intercalatum: occurs in humans in Western
3、and Central Africa2024/7/2862024/7/287World-wide distributionGeographic distributionRed: S.jGreen: S.mIt is estimated that 600 million people in 79 countries suffer fromschistosomiasis.2024/7/2882024/7/289Schistosoma japonicum2024/7/28102024/7/2811Schistosomiasis japonicaSchistosomiasis japonica in
4、China in China 0.811 million patients0.811 million patientsEndemic area: 35.2Endemic area: 35.2 hundreds of millions square hundreds of millions square metermeter Schistosomiasis in China2024/7/2812Endemic area of Oncomelania hupensis in China2024/7/2813Godofplague:schistosomiasis , snail fever,biha
5、rziasis2024/7/2814 Saying goodbye to the God of plagueSaying Goodbye to the God of Disease 2024/7/2815MauvewatersandgreenmountainsarenothingWhenthegreatancientdoctorHuaTuoCouldnotdefeatatinyworm.Athousandvillagescollapsed,werechokedwithweeds,Menwerelostarrows,ghostssangInthedoorwayofafewdesolatehous
6、es.Yetnowinaday,weleaparoundtheearth,Orexploreathousandmilkyways.AndifthecowherdwholivesonastarAsksabouttheGodofplagues,Tellhim,happyorsad,TheGodisgone,Washedawayinthewaters.Centuries-old disease:schistosomiasisor snail fever2024/7/28162024/7/28172024/7/2818Schistosoma Detected in Ancient Mummies(Nu
7、bian mummies (including this one) are often naturally preserved.)Some anecdotes about schistosomes2024/7/2819Battle of Leyte during the world war IITheBattle of LeyteinthePacificcampaignofWorldWarIIwastheamphibiousinvasionoftheGulfofLeyteinthePhilippinesbyAmericanforcesandFilipinoguerrillasunderthec
8、ommandofGeneralDouglasMacArthur2024/7/2820Large numbers of American and Australian troops serving on the island of Leyte acquired the schistosome infection2024/7/28212024/7/2822Three kingdoms2024/7/28232024/7/2824Hundreds and thousands of troops ruled by Cao Cao were infected with schstosomiasisThe
9、great and invincible troops ruled by Cao Cao were defeated by Schistosomajaponicum ?2024/7/2825EgyptNapoleons.Obsession 2024/7/2826On July 1, 1798, a French invasion force under the command of Napoleon disembarked near Alexandria. The invasion force, which had sailed from Toulon on May 19, was accom
10、panied by a commission of scholars and scientists whose function was to investigate every aspect of life in ancient and contemporary Egypt.Napoleon Ponarpart troops2024/7/28272024/7/2828Schistosomiasis was a major problem for EgyptianFishing in the swamps on the edges of the Nile Riverfrom the tomb
11、of the astronomer NakhtSixth Dynasty (New Kingdom, ca. 1400 BC)Schistosoma japonicum2024/7/28292024/7/2830 Morphology Adult is dioecious both male and female pair up Male: 10-22mm0.5mm 7 testes in a single row. white, gynecophoral canal,2024/7/2831 Female: Dark brown, 20-25mm0.3mm the position of ov
12、ary is near mid body, ceca fuse behind ovary. 2024/7/28322024/7/2833Egg: pale yellow, without operculum a small lateral spine, debris adherent to the shell in fresh egg a miracidium in it. 2024/7/28342024/7/2835eggMiracidium excrete soluble eggs antigen (SEA) , which exudates through eggshell. Alive
13、 miracidium2024/7/2836 Miracidium: covered with cilia pear-size Cercariae: Body, tail trunk: fork tailed, and a pair of furcae schistosomulumLife cycle2024/7/2837Life cycle2024/7/2838Adult (in the portal egg eggs miracidiaSystem and mesentericVein) mother-sporocystschistosomula cercariae daughter-sp
14、orocyst Thousands ofEscape from theSnail and penetrateskin(0.6-1min)Enter the oncome-lania (only oneintermediate hostEnter peripheral vessels,pass throughright heart, lung,reach intrahepaticportal system, thenmigrate into themesenteric vein, theworms mated, andto be mature11 days for eggs to mature,
15、 SEAsecreted by miracidium causethe eosinophilic abscess, eggsescape and are discharged intothe lumen, and passed in thefeces into water, to hatchTypical habitat of S.japonicum is the radicals of the superior mesentericVeinthe female oviposition eggsbreak throughthe submucosa and mucosaMigrate to li
16、ver2024/7/2839Biology of schistosome japonicum2024/7/2840Adults living in portal systems2024/7/28412024/7/2842 mesenteric vein1. Adults locations： portal system， pairs with the opposite sex， take blood meal。2024/7/28432. Females deposition and ova development：(1) in mesenteric veins 300 to 3000/ a d
17、ay (2) egg deposit position： Large amount of eggs in intestinal tissueSome deposit in liverfew ova in brain , lung(3) Ova maturity，need 10 days in tissue。2024/7/2844(4) Miracidium secrete（SEA)，causing intestinal inflammation necrosis necrotic discharge with egg be passed out 。3. Miracidium hatch in
18、fresh water(1) miracidium can live for few hours2024/7/2845(2(2）factors of effecting hatchfactors of effecting hatch water qualitywater quality：very cleanvery clean temperaturetemperature：2530 2530 pHpH： 7.5 7.8 7.5 7.8 illuminationilluminationilluminationillumination： 4 4、Development of miracidium
19、in snail Development of miracidium in snail 1 1）One miracidium can develop more than thousands One miracidium can develop more than thousands of cercariae of cercariae 2 2）Cercarium life span: 13daysCercarium life span: 13days 2024/7/2846 Comfortable environment: pH: 6.67.8 2025， illumination5、Schis
20、tosomulum6、Migration and inhabitingLarval migration wayAt the mesenteric vein2024/7/28472024/7/2848schistosomula2024/7/2849 PathogenesisPathogenesis1、 Cercariae and schistosomulaCercariae and schistosomula Cercarial dermatitis： type I and type IV (swimmers itch) hypersensitivity reactionPetechial he
21、morrhages occur, local edema, more sensitive, ItchingPapular skin rash2024/7/2850 Larval phlebitis and punctate hemorrhage in lung tissue Clinical features: fever, cough, bloody cough , eosinophilia2、Adult worms Adult worms （1） phlebitis （2） type hypersensitivity reaction (renal failure)In general,
22、adults doesnt cause pathological changes significantly.2024/7/2851（3）Egg Th cellcirrhosiscirrhosisSEASEAmacrophages APC polypolypeosinophilic eosinophilic abscessabscess granulomagranuloma fibrosisfibrosisMechanism : IV hypersensitivity reactionMechanism : IV hypersensitivity reaction lymphokineslym
23、phokines Granulomatous cell-mediate responses by eosinophils/ lymphocytes/macrophages 2024/7/2852Mechanism of formation of granuloma2024/7/28532024/7/2854 Portal hypertensionLate in the diseasePipestem fibrosis in liver and fibrosis in intestinal wallsAbdominal varicesascitesPolyp, and cancerationsp
24、lenomegalyEsophagogastric varices2024/7/2855Esophagus vein varices2024/7/2856Rabbit liver with infected with S.jMiliary tubercles(granuloma)2024/7/2857Many eggs in liver2024/7/2858Acute stage of granuloma of S.japonicum2024/7/2859Chronic stage of granuloma with S. japonicum2024/7/2860Advanced stage
25、of granuloma withS.japonicum (Pipestem cirrhosis)Fibrosis bandalong the trajectory of the portal vein2024/7/28612. Clinic presentationsClinic presentations 1）Acute schistosomiasis fever fever stool with blood and mucus stool with blood and mucus hepatosplenomegaly hepatosplenomegaly cough, hemoptysi
26、s cough, hemoptysis 15-20% eosinophlia15-20% eosinophlia2024/7/28622 2）Chronic stage :Chronic stage : asymptom asymptom fatiguefatigue、abdominal painabdominal pain、diarrhoea diarrhoea 、 hepatosplenomegaly Totally in 90%Chronic schistosomiasis2024/7/2863 3) Advanced stage 5 years after infection. spl
27、enomegaly, ascites, colon-hyperplasia (polyposis), dwarfism.2024/7/2864Complications:Gastroduodenal hemorrhagehepatic coma 1.65.4%，hepatitis Bhepatorenal syndrome infectious shockcanceration2024/7/28654) Salmonella-Schistosoma syndrome intermittent fever 5) Ectopic lesion Cerebral form：Pulmonary for
28、m: Ectopic lesions：skin、thyroid gland and so on2024/7/2866Ascites2024/7/2867Dwarfism Ascites2024/7/2868Abdominalvarixhernia2024/7/28692024/7/2870Dwarfism2024/7/2871Immunity 1 Innate immunity 2 Acquired immunity Immuneresponse2024/7/28722024/7/2873Concomitant immunity : The adult worms and generating
29、 an immune effector mechanism that can really destroy schistosomula but to which they themselves are resistant. Immune evasion、Immune evasionDiagnosis2024/7/28741. Laboratory examination(1) Direct fecal smear (2) Sedimentation-hatching method (3) Katos thick smear (4) Rectal biopsyproblemPositive ra
30、te is very low in detecting schistosomiasis with chronic and advanced stages 2024/7/28752. Immunologic methods Circulating antibody Circumoval precipitin test (COPT)ELISA, IHA, ELIB, Dipstick assay.Circulating antigen Dot-ELISA, sanswish-ELISA 5%, Positive5%, Positive3%, negative3%, negative2024/7/2
31、876 Epidemiology 1.Distribution1.Distribution： China, Philippine, Indonesia. Japan?China, Philippine, Indonesia. Japan? In ChinaIn China：Jiangxi,Hunan,Jiangxi,Hunan,Hubei,Anhui andHubei,Anhui andJiangsu ProvincesJiangsu ProvincesYunnan, SichuangYunnan, SichuangGeographic distribution in China2024/7/
32、2877Types of endemic areas in China： Three sorts：Water-net regions of plain : 7.9% Marshy regions ; 82.1%Hill area 10% 2024/7/28782. Epidemic links （1) infectious source patients、career and reservoir hostsMain reservoirs of infection:Main reservoirs of infection: infected livestock, infected livesto
33、ck, more than 31 more than 31 mammals, and rodentsmammals, and rodentsMajor reservoirs in China2024/7/2879Cattle: scalpers and water buffalo2024/7/2880(2)Transimission: the way to infection: contacting the water containing cercaria. Oncomelania hubensis 2024/7/2881(3) Susceptible population humans i
34、s a susceptible host of S.jPrevention and Treatment1、Control objective to reduce morbidity in areas of the high endemicity( areas with 15% prevalence) to control morbidity in areas of medium endemicity(areas with prevalence 3% and 15%) to control morbidity and transmission in areas of low endemicity
35、(areas with prevalence 3%) 2024/7/28822、Control measuresIn areas of high endemicity:Schistosomiasis is treatable using a single dose of the drug praziquantel by mouth annually Mass chemotherapy, drug - praziquental Artesunate and artemether against schistosomulaSnail control：limited snail control by
36、 mollusciding with niclosamide, and environment modification. In areas of medium and low endemicity :Selective chemotherapy for human and livestock,Healthy education2024/7/2883“以机代牛以机代牛”2024/7/2884Snail control2024/7/2885Drinking water safety2024/7/2886Control of feces2024/7/28873、Individual prevent
37、ionAvoid exposure to infested waterDrugs: Artemether and Artesunate.Some ointment used 2024/7/2888Schistosoma mansoni(S.m) Schistosoma haematobium(S.h) Lateral spine terminal spine2024/7/28892024/7/2890 Geographic distribution: S.m S.h2024/7/28912024/7/2892Intermediate host of S.m BiomphalariaInterm
38、ediate host of S.h Bulinus2024/7/28932024/7/28942024/7/2895Pathogenesis: S.m S. h hematuria2024/7/2896S.m. S.h.2024/7/2897Photomicrography of bladder in S. hematobium infection, showing clusters of the parasite eggs with intense eosinophilia,2024/7/2898Taking medication, praziquantelSchistosomiasis
39、is treatable using a single dose of the drug praziquantel by mouth annuallyOther possible treatments include a combination of praziquantel with metrifonate, artesunate or mefloquine.2024/7/2899SummarySPECIES PRINCIPLE DEFINITIVE HOST(S) SITE OF INFECTION METACERCARIAE LOCATION OF EGGS Clonorchis sin
40、ensis humans bile ducts FW fish feces Fasciolopsis buski primates; swine small intestine FW plants feces Paragonimus westermani humans; lungs FW crabs feces; sputum Schistosoma haematobium humans mesenteric veins around urinary bladder none; cercariae penetrate directly urine Schistosoma japonicum h
41、umans mesenteric veins around small intestine none; cercariae penetrate directly feces Schistosoma mansoni humans mesenteric veins around large intestine none; cercariae penetrate directly feces 2024/7/281002024/7/281012024/7/28102Sigmoid colonic carcinoma associated with deposited ova of Schistosom
42、a japonicum: A case report 2024/7/28103A57-yearoldwomanpresentedwitha10-mohistoryofleftlowerquadrantabdominalpainanda2-mohistoryofbloodystools.Shehadasenseofpainintheleftlowerquadrantabdomenwhenshehadbowelmovementsabout10moago.Thepainwasrelievedafterdefecation,sothatshedidnotthinkmuchofit.Twomonthsa
43、go,shenotedthatdarkredbloodadheredtothesurfaceofstoolswithoutblooddropsfromanus.Thesymptomofhematocheziapersisteduntilhospitalization.Shehadnoothercomplaints.Shehadasignificantpastmedicalhistoryofasymptomaticschistosomiasisjaponicaandconstipation.ShecamefromCase report 12024/7/28104theruralareainZhe
44、jiangProvince,whereschistosomiasisjaponicawasprevalentseveraldecadesago.Shehadtheexperienceofswimminginalocalriverinherchildhood.Attheageof13,shewasdiagnosedwithschistosomiasisthroughathicksmearstoolexaminationbythecountypublichealthworkersforschistosomiasiscontrol,andgiventheappropriateantischistos
45、omiasistherapywhichwasnotterminateduntilrepeatedstoolexaminationswerenegative.Attheageof20,shesufferedfromconstipationwhichwasnotimprovedbyadequatefiberintake.Usually,shehadabouttwobowelmovementswithhardstoolsperweek.Thesymptombegantobecomeworsetenyearsagoandshehaddefecationonceperweek.2024/7/28105T
46、heabdominalultrasonographyrevealedechodenseareasscatteredwithintheparenchymawithtypicalfish-scalepattern,representingthetraitofliverschistosomiasis.Thecomputedtomographicscanshowedthatthebowelwallofsigmoidcolonwasincrassatedandirregularinshape.Thecolonoscopyshowedanexophyticfragileneoplasmwithanulce
47、ratingsurfaceinthesigmoidcolonQuestions How does the person acquire this infection?What factor in the patient history might predispose him to this infection?What internal organs might be involved in this disease?What is the recommended treatment for this disease?Case study 22024/7/28106A68-yearoldma
48、lepresentedtotheemergencyroom,sufferingfromcough,chestpain,somedifficultybreathing,andblood-tingedsputum.Sputumspecimensweresentforroutinemicrobiologicalculture,culturefortuberculosis,andanexaminationforparasites.Hematologystudiesshowedmoderateeosinophilia.Thepatientshistorywasunremarkable,exceptfor
49、amealof“slightly-steamed”crabseaten12weeksearlier.Thesputumcultureswerenegativeforpathogens.Examinationofsputumforparasitesrevealedoperculatedhelminthova,measuring100by50um.Questions2024/7/28107Whatisthenameoftheparasitewhichiscausingthispatientssymptoms?Howwouldyourelatedthelifecycleofthisparasitetothepatientsillness?Whatistherelationshipbetweenthesteamedcrabdinnerandthepatientsillness?Whatotherhelminthproduceseggswhichcouldbeconfusedwiththisparasite?explain2024/7/28108
