( ( Blood Blood fluke )fluke )2024/7/311 Schistosome2024/7/3122024/7/3132024/7/3142024/7/315Six 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 EastSchistosoma 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 and Central Africa2024/7/3162024/7/317World-wide distributionGeographic distributionRed: S.jGreen: S.mIt is estimated that 600 million people in 79 countries suffer fromschistosomiasis.2024/7/3182024/7/319Schistosoma japonicum2024/7/31102024/7/3111Schistosomiasis japonicaSchistosomiasis japonica in 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 China2024/7/3112Endemic area of Oncomelania hupensis in China2024/7/3113Godofplague:schistosomiasis , snail fever,biharziasis2024/7/3114 Saying goodbye to the God of plagueSaying Goodbye to the God of Disease 2024/7/3115MauvewatersandgreenmountainsarenothingWhenthegreatancientdoctorHuaTuoCouldnotdefeatatinyworm.Athousandvillagescollapsed,werechokedwithweeds,Menwerelostarrows,ghostssangInthedoorwayofafewdesolatehouses.Yetnowinaday,weleaparoundtheearth,Orexploreathousandmilkyways.AndifthecowherdwholivesonastarAsksabouttheGodofplagues,Tellhim,happyorsad,TheGodisgone,Washedawayinthewaters.Centuries-old disease:schistosomiasisor snail fever2024/7/31162024/7/31172024/7/3118Schistosoma Detected in Ancient Mummies(Nubian mummies (including this one) are often naturally preserved.)Some anecdotes about schistosomes2024/7/3119Battle of Leyte during the world war IITheBattle of LeyteinthePacificcampaignofWorldWarIIwastheamphibiousinvasionoftheGulfofLeyteinthePhilippinesbyAmericanforcesandFilipinoguerrillasunderthecommandofGeneralDouglasMacArthur2024/7/3120Large numbers of American and Australian troops serving on the island of Leyte acquired the schistosome infection2024/7/31212024/7/3122Three kingdoms2024/7/31232024/7/3124Hundreds and thousands of troops ruled by Cao Cao were infected with schstosomiasisThe great and invincible troops ruled by Cao Cao were defeated by Schistosomajaponicum ?2024/7/3125EgyptNapoleons.Obsession 2024/7/3126On 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 accompanied by a commission of scholars and scientists whose function was to investigate every aspect of life in ancient and contemporary Egypt.Napoleon Ponarpart troops2024/7/31272024/7/3128Schistosomiasis was a major problem for EgyptianFishing in the swamps on the edges of the Nile Riverfrom the tomb of the astronomer NakhtSixth Dynasty (New Kingdom, ca. 1400 BC)Schistosoma japonicum2024/7/31292024/7/3130 Morphology Adult is dioecious both male and female pair up Male: 10-22mm0.5mm 7 testes in a single row. white, gynecophoral canal,2024/7/3131 Female: Dark brown, 20-25mm0.3mm the position of ovary is near mid body, ceca fuse behind ovary. 2024/7/31322024/7/3133Egg: pale yellow, without operculum a small lateral spine, debris adherent to the shell in fresh egg a miracidium in it. 2024/7/31342024/7/3135eggMiracidium excrete soluble eggs antigen (SEA) , which exudates through eggshell. Alive miracidium2024/7/3136 Miracidium: covered with cilia pear-size Cercariae: Body, tail trunk: fork tailed, and a pair of furcae schistosomulumLife cycle2024/7/3137Life cycle2024/7/3138Adult (in the portal egg eggs miracidiaSystem and mesentericVein) mother-sporocystschistosomula cercariae daughter-sporocyst 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, 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 liver2024/7/3139Biology of schistosome japonicum2024/7/3140Adults living in portal systems2024/7/31412024/7/3142 mesenteric vein1. Adults locations： portal system， pairs with the opposite sex， take blood meal。2024/7/31432. Females deposition and ova development：(1) in mesenteric veins 300 to 3000/ a day (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。2024/7/3144(4) Miracidium secrete（SEA)，causing intestinal inflammation necrosis necrotic discharge with egg be passed out 。3. Miracidium hatch in fresh water(1) miracidium can live for few hours2024/7/3145(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 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 2024/7/3146 Comfortable environment: pH: 6.67.8 2025， illumination5、Schistosomulum6、Migration and inhabitingLarval migration wayAt the mesenteric vein2024/7/31472024/7/3148schistosomula2024/7/3149 PathogenesisPathogenesis1、 Cercariae and schistosomulaCercariae and schistosomula Cercarial dermatitis： type I and type IV (swimmers itch) hypersensitivity reactionPetechial hemorrhages occur, local edema, more sensitive, ItchingPapular skin rash2024/7/3150 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, adults doesnt cause pathological changes significantly.2024/7/3151（3）Egg Th cellcirrhosiscirrhosisSEASEAmacrophages APC polypolypeosinophilic eosinophilic abscessabscess granulomagranuloma fibrosisfibrosisMechanism : IV hypersensitivity reactionMechanism : IV hypersensitivity reaction lymphokineslymphokines Granulomatous cell-mediate responses by eosinophils/ lymphocytes/macrophages 2024/7/3152Mechanism of formation of granuloma2024/7/31532024/7/3154 Portal hypertensionLate in the diseasePipestem fibrosis in liver and fibrosis in intestinal wallsAbdominal varicesascitesPolyp, and cancerationsplenomegalyEsophagogastric varices2024/7/3155Esophagus vein varices2024/7/3156Rabbit liver with infected with S.jMiliary tubercles(granuloma)2024/7/3157Many eggs in liver2024/7/3158Acute stage of granuloma of S.japonicum2024/7/3159Chronic stage of granuloma with S. japonicum2024/7/3160Advanced stage of granuloma withS.japonicum (Pipestem cirrhosis)Fibrosis bandalong the trajectory of the portal vein2024/7/31612. Clinic presentationsClinic presentations 1）Acute schistosomiasis fever fever stool with blood and mucus stool with blood and mucus hepatosplenomegaly hepatosplenomegaly cough, hemoptysis cough, hemoptysis 15-20% eosinophlia15-20% eosinophlia2024/7/31622 2）Chronic stage :Chronic stage : asymptom asymptom fatiguefatigue、abdominal painabdominal pain、diarrhoea diarrhoea 、 hepatosplenomegaly Totally in 90%Chronic schistosomiasis2024/7/3163 3) Advanced stage 5 years after infection. splenomegaly, ascites, colon-hyperplasia (polyposis), dwarfism.2024/7/3164Complications:Gastroduodenal hemorrhagehepatic coma 1.65.4%，hepatitis Bhepatorenal syndrome infectious shockcanceration2024/7/31654) Salmonella-Schistosoma syndrome intermittent fever 5) Ectopic lesion Cerebral form：Pulmonary form: Ectopic lesions：skin、thyroid gland and so on2024/7/3166Ascites2024/7/3167Dwarfism Ascites2024/7/3168Abdominalvarixhernia2024/7/31692024/7/3170Dwarfism2024/7/3171Immunity 1 Innate immunity 2 Acquired immunity Immuneresponse2024/7/31722024/7/3173Concomitant immunity : The adult worms and generating an immune effector mechanism that can really destroy schistosomula but to which they themselves are resistant. Immune evasion、Immune evasionDiagnosis2024/7/31741. Laboratory examination(1) Direct fecal smear (2) Sedimentation-hatching method (3) Katos thick smear (4) Rectal biopsyproblemPositive rate is very low in detecting schistosomiasis with chronic and advanced stages 2024/7/31752. Immunologic methods Circulating antibody Circumoval precipitin test (COPT)ELISA, IHA, ELIB, Dipstick assay.Circulating antigen Dot-ELISA, sanswish-ELISA 5%, Positive5%, Positive3%, negative3%, negative2024/7/3176 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 China2024/7/3177Types of endemic areas in China： Three sorts：Water-net regions of plain : 7.9% Marshy regions ; 82.1%Hill area 10% 2024/7/31782. Epidemic links （1) infectious source patients、career and reservoir hostsMain reservoirs of infection:Main reservoirs of infection: infected livestock, infected livestock, more than 31 more than 31 mammals, and rodentsmammals, and rodentsMajor reservoirs in China2024/7/3179Cattle: scalpers and water buffalo2024/7/3180(2)Transimission: the way to infection: contacting the water containing cercaria. Oncomelania hubensis 2024/7/3181(3) Susceptible population humans is 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(areas with prevalence 3%) 2024/7/31822、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 mollusciding with niclosamide, and environment modification. In areas of medium and low endemicity :Selective chemotherapy for human and livestock,Healthy education2024/7/3183“以机代牛以机代牛”2024/7/3184Snail control2024/7/3185Drinking water safety2024/7/3186Control of feces2024/7/31873、Individual preventionAvoid exposure to infested waterDrugs: Artemether and Artesunate.Some ointment used 2024/7/3188Schistosoma mansoni(S.m) Schistosoma haematobium(S.h) Lateral spine terminal spine2024/7/31892024/7/3190 Geographic distribution: S.m S.h2024/7/31912024/7/3192Intermediate host of S.m BiomphalariaIntermediate host of S.h Bulinus2024/7/31932024/7/31942024/7/3195Pathogenesis: S.m S. h hematuria2024/7/3196S.m. S.h.2024/7/3197Photomicrography of bladder in S. hematobium infection, showing clusters of the parasite eggs with intense eosinophilia,2024/7/3198Taking medication, praziquantelSchistosomiasis 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.2024/7/3199SummarySPECIES PRINCIPLE DEFINITIVE HOST(S) SITE OF INFECTION METACERCARIAE LOCATION OF EGGS Clonorchis sinensis 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 humans mesenteric veins around small intestine none; cercariae penetrate directly feces Schistosoma mansoni humans mesenteric veins around large intestine none; cercariae penetrate directly feces 2024/7/311002024/7/311012024/7/31102Sigmoid colonic carcinoma associated with deposited ova of Schistosoma japonicum: A case report 2024/7/31103A57-yearoldwomanpresentedwitha10-mohistoryofleftlowerquadrantabdominalpainanda2-mohistoryofbloodystools.Shehadasenseofpainintheleftlowerquadrantabdomenwhenshehadbowelmovementsabout10moago.Thepainwasrelievedafterdefecation,sothatshedidnotthinkmuchofit.Twomonthsago,shenotedthatdarkredbloodadheredtothesurfaceofstoolswithoutblooddropsfromanus.Thesymptomofhematocheziapersisteduntilhospitalization.Shehadnoothercomplaints.Shehadasignificantpastmedicalhistoryofasymptomaticschistosomiasisjaponicaandconstipation.ShecamefromCase report 12024/7/31104theruralareainZhejiangProvince,whereschistosomiasisjaponicawasprevalentseveraldecadesago.Shehadtheexperienceofswimminginalocalriverinherchildhood.Attheageof13,shewasdiagnosedwithschistosomiasisthroughathicksmearstoolexaminationbythecountypublichealthworkersforschistosomiasiscontrol,andgiventheappropriateantischistosomiasistherapywhichwasnotterminateduntilrepeatedstoolexaminationswerenegative.Attheageof20,shesufferedfromconstipationwhichwasnotimprovedbyadequatefiberintake.Usually,shehadabouttwobowelmovementswithhardstoolsperweek.Thesymptombegantobecomeworsetenyearsagoandshehaddefecationonceperweek.2024/7/31105Theabdominalultrasonographyrevealedechodenseareasscatteredwithintheparenchymawithtypicalfish-scalepattern,representingthetraitofliverschistosomiasis.Thecomputedtomographicscanshowedthatthebowelwallofsigmoidcolonwasincrassatedandirregularinshape.ThecolonoscopyshowedanexophyticfragileneoplasmwithanulceratingsurfaceinthesigmoidcolonQuestions 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 22024/7/31106A68-yearoldmalepresentedtotheemergencyroom,sufferingfromcough,chestpain,somedifficultybreathing,andblood-tingedsputum.Sputumspecimensweresentforroutinemicrobiologicalculture,culturefortuberculosis,andanexaminationforparasites.Hematologystudiesshowedmoderateeosinophilia.Thepatientshistorywasunremarkable,exceptforamealof“slightly-steamed”crabseaten12weeksearlier.Thesputumcultureswerenegativeforpathogens.Examinationofsputumforparasitesrevealedoperculatedhelminthova,measuring100by50um.Questions2024/7/31107Whatisthenameoftheparasitewhichiscausingthispatientssymptoms?Howwouldyourelatedthelifecycleofthisparasitetothepatientsillness?Whatistherelationshipbetweenthesteamedcrabdinnerandthepatientsillness?Whatotherhelminthproduceseggswhichcouldbeconfusedwiththisparasite?explain2024/7/31108