醫(yī)學(xué)寄生蟲(chóng)學(xué)課件：6schistosome

1、 ( ( Blood Blood fluke )fluke )2021-12-21 Schistosome2021-12-222021-12-232021-12-242021-12-25Six species of schistosome: Schistosoma japonicum Schistosoma haematobium Schistosoma mansoni S. intercalatum S. mekongi S. malayiSchistosoma japonicumSchistosoma japonicum: the Oriental blood : the Oriental

2、 blood fluke is confined to the Far Eastfluke is confined to the Far EastSchistosoma masoni:occurs: Schistosoma masoni:occurs: extensive areas of extensive areas of Africa and in the Arabian peninsula and Africa and in the Arabian peninsula and MalagasyMalagasySchistosoma haematobiumSchistosoma haem

3、atobium: was apparently the : was apparently the Nile Valley, Africa, and so on.Nile Valley, Africa, and so on.Schistosoma MekongiSchistosoma Mekongi: from the Mekong River : from the Mekong River basin in shouthern Laos and Cambodiabasin in shouthern Laos and CambodiaSchistosoma intercalatum: Schis

4、tosoma intercalatum: occurs in humans in occurs in humans in Western and Central AfricaWestern and Central Africa2021-12-262021-12-27Geographic distributionRed: S.jGreen: S.mIt is estimated that 600 million people in 79 countries suffer fromschistosomiasis.2021-12-282021-12-29Schistosoma japonicumSc

5、histosoma japonicum2021-12-2102021-12-211Schistosomiasis japonica in China 0.811 million patientsEndemic area: 35.2 hundreds of millions square meter Schistosomiasis in China2021-12-212Endemic area of Oncomelania hupensis in China2021-12-213God of plague:schistosomiasis , snail fever,biharziasis2021

6、-12-214 Saying goodbye to the God of plagueSaying Goodbye to the God of Saying Goodbye to the God of Disease Disease 2021-12-215 Mauve waters and green mountains are nothing When the great ancient doctor Hua Tuo Could not defeat a tiny worm. A thousand villages collapsed, were choked with weeds, Men

7、 were lost arrows, ghosts sang In the doorway of a few desolate houses. Yet now in a day, we leap around the earth, Or explore a thousand milky ways. And if the cowherd who lives on a star Asks about the God of plagues, Tell him, happy or sad, The God is gone, Washed away in the waters. Centuries-ol

8、d disease:Centuries-old disease:schistosomiasisschistosomiasisor snail feveror snail fever2021-12-216It was said that the prevalence of schistosomiasishas continued for more than 2200 years in China2021-12-2172021-12-218Schistosoma Detected in Ancient Mummies(Nubian mummies (including this one) are

9、often naturally preserved.)Some anecdotes about schistosomes2021-12-219Battle of Leyte during the world Battle of Leyte during the world war IIwar IIThe Battle of LeyteBattle of Leyte in the Pacific campaign of World War II was the amphibious invasion of the Gulf of Leyte in the Philippines by Ameri

10、can forces and Filipino guerrillas under the command of General Douglas MacArthur2021-12-220Large numbers of Large numbers of American and Australian American and Australian troops serving on the troops serving on the island of Leyte island of Leyte acquired the acquired the schistosome infectionsch

11、istosome infection2021-12-2212021-12-222In 208 A.D., in the Han Dynasty of China, the tyrannic and greedy Prime Minster Cao Cao led an army of 800,000 men south against Liu Bei and Sun Quan, who had only about 100,000 men between them. Cao Cao embarked his men on ships, and the fleet sailed up the Y

12、angtze River, and anchored at a place called the Red Cliff (in todays Chibi City, Hubei Province, although it has been alternately located in the northeast of todays Jiayu County in Hubei). The ships were chained together. One night, when the wind was favorable, Zhuge Liang dispatched a general with

13、 10 ships to sail toward the enemy, pretending to be surrendering. The ships were loaded with firewood soaked in oil. When they were near enough to Cao Caos fleet, they were set on fire and left to drift into the enemy ships, which were totally destroyed. Great War: the Battle of Red Cliff2021-12-22

14、3Great War: Red CliffThe armies fight against each other in many battles until the final one in Red Cliff where guile, knowledge and strategy prevail. Numerous battles of wits and forces, on land and on water, eventually culminated into the most famous battle in Chinese history, where two thousand s

15、hips were burned, and the course of Chinas history was changed forever. 2021-12-224The battlefield was identified the severely endemic area where distributed Schistosoma japonicumHundreds and thousands of troops ruled by Cao Cao were infected with schstosomiasisThe great and invincible troops ruled

16、by Cao The great and invincible troops ruled by Cao Cao were defeated by Schistosomajaponicum ?Cao were defeated by Schistosomajaponicum ?2021-12-225EgyptEgyptNapoleons.ObsessionNapoleons.Obsession 2021-12-226On July 1, 1798, a French invasion On July 1, 1798, a French invasion force under the comma

17、nd of Napoleon force under the command of Napoleon disembarked near Alexandria. The disembarked near Alexandria. The invasion force, which had sailed from invasion force, which had sailed from Toulon on May 19, was accompanied by a Toulon on May 19, was accompanied by a commission of scholars and sc

18、ientists commission of scholars and scientists whose function was to investigate whose function was to investigate every aspect of life in ancient and every aspect of life in ancient and contemporary Egyptcontemporary Egypt. .Napoleon Ponarpart troopsNapoleon Ponarpart troops2021-12-2272021-12-228Sc

19、histosomiasis 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 japonicumSchistosoma japonicum2021-12-2292021-12-230 Morphology Adult is dioecious both male and female pair up M

20、ale: 10-22mm0.5mm 7 testes in a single row. white, gynecophoral canal,2021-12-231 Female: Dark brown, 20-25mm0.3mm the position of ovary is near mid body, ceca fuse behind ovary. 2021-12-2322021-12-233Egg: pale yellow, without operculum a small lateral spine, debris adherent to the shell in fresh eg

21、g a miracidium in it. 2021-12-2342021-12-235eggMiracidium excrete soluble eggs antigen (SEA) , which exudates through eggshell. Alive miracidium2021-12-236 Miracidium: covered with cilia pear-size Cercariae: Body, tail trunk: fork tailed, and a pair of furcae schistosomulumLife cycleLife cycle2021-1

22、2-237Life Life cyclecycle2021-12-238AdultAdult (in the portal egg (in the portal egg eggseggs miracidiamiracidiaSystem and System and mesentericmesentericVein)Vein) mother-mother-sporocystsporocystschistosomulaschistosomula cercariaecercariae daughter-daughter-sporocystsporocyst Thousands ofEscape f

23、rom 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 c

24、ausethe 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 liver2021-12-239Biology of sch

25、istosome Biology of schistosome japonicumjaponicum2021-12-240Adults living in portal systemsAdults living in portal systems2021-12-2412021-12-242 mesenteric vein1. Adults locations： portal system， pairs with the opposite sex， take blood meal。Adult life span : 4.5 to 35 years2021-12-2432. Females dep

26、osition 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。2021-12-244(4) Miracidium secrete（SEA)，causing intestinal inflammation necrosi

27、s necrotic discharge with egg be passed out 。3. Miracidium hatch in fresh water(1) miracidium can live for few hours2021-12-245(2）factors of effecting hatch water quality：very clean temperature：2530 pH： 7.5 7.8 illuminationillumination： 4、Development of miracidium in snail 1）One miracidium can devel

28、op more than thousands of cercariae 2）Cercarium life span: 13days 2021-12-246 Comfortable environment: pH: 6.67.8 2025， illumination5、Schistosomulum6、Migration and inhabitingSchistosomula enter the peripheral and lymphatic, and are escaped off to the right heart, then arrive at pulmonary capillaries

29、. 10 days later, they move through the pulmonary vein to the left side of heart into the systemic circulation. They reach the liver via the mesenteric arteries, capillaries andhepatoportal vein or liver artery. Larval migration wayAt the mesenteric veinAt the mesenteric vein2021-12-247Female resides

30、 in the malesgynecophoral canal2021-12-248schistosomula2021-12-2491、 Cercarial dermatitis： type I and type IV (swimmers itch) hypersensitivity reactionPetechial hemorrhages occur, local edema, more sensitive, ItchingPapular skin rash2021-12-250 Larval phlebitis and punctate hemorrhage in lung tissue

31、 Clinical features: fever, cough, bloody cough , eosinophilia2、 （1） phlebitis （2） type hypersensitivity reaction (renal failure)2021-12-251（3）Egg Th cellcirrhosiscirrhosisSEASEAmacrophages APC polypolyp Granulomatous cell-mediate responses by eosinophils/ lymphocytes/macrophages 2021-12-252Mechanism

32、 of formation of granuloma2021-12-2532021-12-254 Portal hypertensionLate in the diseasePipestem fibrosis in liver and fibrosis in intestinal wallsAbdominal varicesascitesPolyp, and cancerationsplenomegalyEsophagogastric varices2021-12-255Esophagus vein varices2021-12-256Rabbit liver with infected wi

33、th S.jMiliary tubercles(granuloma)2021-12-257Many eggs in liver2021-12-258Acute stage of granuloma of S.japonicum2021-12-259Chronic stage of granuloma with S. japonicum2021-12-260Advanced stage of granuloma withS.japonicum (Pipestem cirrhosis)Fibrosis bandalong the trajectory of the portal vein2021-

34、12-261 2. 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% eosinophlia2021-12-2622 2）Chronic stage :Chronic stage : asy

35、mptom asymptom fatiguefatigue、abdominal painabdominal pain、diarrhoea diarrhoea 、 hepatosplenomegaly Totally in 90%Chronic schistosomiasis2021-12-263 3) Advanced stage 5 years after infection. splenomegaly, ascites, colon-hyperplasia (polyposis), dwarfism.2021-12-264Complications:Gastroduodenal hemor

36、rhagehepatic coma 1.65.4%，hepatitis Bhepatorenal syndrome infectious shockcanceration2021-12-2654) Salmonella-Schistosoma syndrome intermittent fever 5) Ectopic lesion Cerebral form：Pulmonary form: Ectopic lesions：skin、thyroid gland and so on2021-12-266Ascites2021-12-267Dwarfism Ascites2021-12-268Ab

37、dominalvarixhernia2021-12-2692021-12-270Dwarfism2021-12-271Immunity 1 Innate immunity 2 Acquired immunity Immune response2021-12-2722021-12-273Concomitant immunity :Concomitant immunity : The adult worms and generating an immune The adult worms and generating an immune effector mechanism that can re

38、ally destroy effector mechanism that can really destroy schistosomula but to which they themselves are schistosomula but to which they themselves are resistant.resistant. Immune evasionImmune evasion、Immune evasionImmune evasion2021-12-2741. Laboratory examination1. Laboratory examination (1) Direct

39、 fecal smear (1) Direct fecal smear (2) Sedimentation-hatching method (2) Sedimentation-hatching method (3) (3) Katos thick smearKatos thick smear (4) Rectal biopsy (4) Rectal biopsyproblemPositive rate is very low in detecting schistosomiasis with chronic and advanced stages 2021-12-2752. Immunolog

40、ic methods Circulating antibody Circumoval precipitin test (COPT)ELISA, IHA, ELIB, Dipstick assay.Circulating antigen Dot-ELISA, sanswish-ELISA 5%, Positive5%, Positive3%, negative3%, negative2021-12-276 Epidemiology 1.Distribution1.Distribution： China, Philippine, Indonesia. Japan?China, Philippine

41、, Indonesia. Japan? In ChinaIn China：Jiangxi,Hunan,Jiangxi,Hunan,Hubei,Anhui andHubei,Anhui andJiangsu ProvincesJiangsu ProvincesYunnan, SichuangYunnan, SichuangGeographic distribution in China2021-12-277Types of endemic areas in China： Three sorts：Water-net regions of plain : 7.9% Marshy regions ;

42、82.1%Hill area 10% 2021-12-2782. Epidemic links （1) infectious source patients、career and reservoir hostsMajor reservoirs in ChinaMajor reservoirs in China2021-12-279Cattle: scalpers and water buffalo2021-12-280(2)Transimission: the way to infection: contacting the water containing cercaria. Oncomel

43、ania hubensis 2021-12-281(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 c

44、ontrol morbidity and transmission in areas of low endemicity(areas with prevalence 3%) 2021-12-2822、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

45、 against schistosomulaSnail controlSnail control：limited snail control by limited snail control by mollusciding with mollusciding with niclosamideniclosamide, and , and environment modification.environment modification. In areas of medium and low endemicity :In areas of medium and low endemicity :Se

46、lective chemotherapy for human and Selective chemotherapy for human and livestock,livestock,Healthy educationHealthy education2021-12-283“以機(jī)代牛以機(jī)代?！?021-12-284Snail control2021-12-285Drinking water safety2021-12-286Control of feces2021-12-2873、Individual preventionAvoid exposure to infested waterDrug

47、s: Artemether and Artesunate.Some ointment used 2021-12-288Schistosoma mansoni(S.m) Schistosoma haematobium(S.h) Lateral spine terminal spine2021-12-2892021-12-290 Geographic distribution: S.m S.h2021-12-2912021-12-292Intermediate host of S.m BiomphalariaIntermediate host of S.h Bulinus2021-12-29320

48、21-12-2942021-12-295Pathogenesis: S.m S. h hematuria2021-12-296S.m. S.h.pathogenesis2021-12-297Photomicrography of bladder in S. hematobium infection, showing clusters of the parasite eggs with intense eosinophilia,2021-12-298Taking medication, praziquantelSchistosomiasis is treatable using a single

49、 dose of the drug praziquantel by mouth annuallyOther possible treatments include a Other possible treatments include a combination of praziquantel with combination of praziquantel with metrifonate, artesunate or mefloquine.metrifonate, artesunate or mefloquine.2021-12-299SummarySummarySPECIES PRINC

50、IPLE 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

51、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 2021-12-21002021-1

52、2-21012021-12-2102Sigmoid colonic carcinoma associated with Sigmoid colonic carcinoma associated with deposited ova of deposited ova of Schistosoma japonicumSchistosoma japonicum: A case : A case reportreport 2021-12-2103A 57-year old woman presented with a 10-mo history of left lower quadrant abdom

53、inal pain and a 2-mo history of bloody stools. She had a sense of pain in the left lower quadrant abdomen when she had bowel movements about 10 mo ago. The pain was relieved after defecation, so that she did not think much of it. Two months ago, she noted that dark red blood adhered to the surface o

54、f stools without blood drops from anus. The symptom of hematochezia persisted until hospitalization. She had no other complaints. She had a significant past medical history of asymptomatic schistosomiasis japonica and constipation. She came from Case report 12021-12-2104the rural area in Zhejiang Pr

55、ovince, where schistosomiasis japonica was prevalent several decades ago. She had the experience of swimming in a local river in her childhood. At the age of 13, she was diagnosed with schistosomiasis through a thick smear stool examination by the county public health workers for schistosomiasis con

56、trol, and given the appropriate antischistosomiasis therapy which was not terminated until repeated stool examinations were negative. At the age of 20, she suffered from constipation which was not improved by adequate fiber intake. Usually, she had about two bowel movements with hard stools per week. The symptom began to become