Microbiology الع نود البستنجي. 1 P a g e

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Candace West
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1 4 Microbiology الع نود البستنجي 19/11/2015 د. ناصر قبالن 1 P a g e

Intestinal Parasites (Helminthes) I will put the slides with Dr notes beside each one and the most important notes I will highlight them in Red color.

2 Intestinal Parasites (Helminthes) I will put the slides with Dr notes beside each one and the most important notes I will highlight them in Red color. Pictures are important for lab exam y Intestinal Helminths) worms) I.Platyhelminths)Flat worms ( 1 Cestodes (Tape-worms). 2 Trematodes) Flukes). and said: you might have one question about it II.Nematihelminths (Round worms /Nematodes) Cestodes (Tape worms ( well Taenia solium (Pork tapeworm) Taenia saginata (Beef tapeworm).cosmopolitan.human is the only definitive host incidence is higher in developing.countries - as 1000 per 1 Infection rate: as low as.10% high as * higher in developing area because of low higene 2 P a g e 23-Nov-14 NM Kaplan 9

3 Adults VERY IMPORTANT Table solium is more dangerous (serious), because it not just GI ifection, but also involved in serious condition "Cysticercosis) * solium has solar appearance, why we call it solium Notice : No hooks 14Nov--23 NM Kaplan 11 more uterus branches 14Nov--23 NM Kaplan 12 3 P a g e

µm 45x brown thick shell with peripheral radial striations eggs

months in environment : (empryonated) Mature oncosphere

hooklets Dr read all of the notes and they are important

proglottids with genital pores in mid-lateral position T.

solium * Important * notice the difference in gravid proglottid

4 Taeniid eggs indistinguishable.morphologically between spp 35rounded or subspherical,.µm 45x brown thick shell with peripheral radial striations eggs survive days-.months in environment : (empryonated) Mature oncosphere hexacanth pairs of 3 embryo with.hooklets Dr read all of the notes and they are important 14Nov--23 NMKaplan 13 Injection of India ink in uterus: Gravid proglottids with genital pores in mid-lateral position T. saginata T. solium * Important * notice the difference in gravid proglottid 14Nov--23 NM Kaplan 14 Life cycle About parasites about each one you should know : 1- caracterstic features 2- infective stage 3- number of hosts In the life cycle 4- food associated with it's position 4 P a g e to be able to diagnose, manage & choose D.O.C

5 Taeniasis.Light infections: asymptomatic Heavier infections: mild GI symptoms as abdominal discomfort, epigastric pain, nausea, vomiting & diarrhea and. weight loss Tinea : infective stage : cysticerci Food : Pork T.solium Breef T.saginata *larvae excyst : larve will brust and cysticerci will go out it. Dr read all of this slide Lab Dx 14Nov--23 NM Kaplan 16 Taeniasis :eggs or gravid proglottids in stool or from perianal area. Rx DOC :Praziquantel or niclosamide: single oral dose. Expulsion of scolex must be assured to assume satisfactory Rx Control Thorough inspection of meat ( pork & beef (Adequate cooking ) internal temp < 56C 5 / min )or freezing of meat ( cysticerci do NOT survive temps o > - 10C & < 50 o C. Adequate sewage disposal. Dr read all of the slide. * to make sure the drug is effective, Expulsion of scolex Cysticercosis Human (intermediate host) infection by T.solium eggs larval cysts in S/C tissue,muscle, heart, lungs & liver. CNS : meningo-encephalitic syndrome with eosinophilia &neurological disorders as epilepsy,psychiatry.! Eye : pain & visual disturbances & blindness. Dx :Hx of travel to endemic area,o&p in stool, immunology assays for specific Abs(useful epidemiological tools (,Radiology & Biopsy. Rx :Prolonged praziquantel or albendazole + steroids,surgery? Dr read the slide one by one,, So it's important. Human in -Teanasis is Definitive host, by eating animal's muscles contain cysticerci - cysticerocis is Intermediate host. T.solium eggs will enter then go anywhere to develop cysticercus. * surgery to remove the cysticercus 5 P a g e

T. solium Cysticercus 14Nov--23 NM Kaplan 19 Dr read the slide Diphyllobothrium

association with eating of raw or undercooked fresh water fish.

*Remember, Red color are the most important otes of the slide Adults 23-Nov-14 NM

)proglottids 3000> reside in small intestine & attach to mucosa by only bilateral

6 T. solium Cysticercus 14Nov--23 NM Kaplan 19 Dr read the slide Diphyllobothrium latum (Fish tapeworm) Worldwide, endemic in subarctic & temperate regions in association with eating of raw or undercooked fresh water fish. Definitive hosts: human & many other mammals. *Remember, Red color are the most important otes of the slide Adults 23-Nov-14 NM Kaplan 20 10>-3(Longest tapeworm meters in length with.)proglottids 3000> reside in small intestine & attach to mucosa by only bilateral longitudinal 2 bothria) (sucking groves of their scolex w resembles two almond-.shaped leaves Scoelx Dr read the slide * Di = bilateral 2 bothria 14Nov--23 NM Kaplan 21 6 P a g e

Gravid proglottids passed in stool in strands.

longer Broad.)tapeworm with ccc centrally positioned, rosette-.

center of proglottid 14Nov--23 NM Kaplan 22 Eggs :)Immature (unembryonated

)eggs/ worm/ day1,000,000 5-6 weeks after.

with40-51x76-58( arrows) (At one end, operculum.

barely discernible mature under appropriate.

because the gravid proglottid is broader than longer.

7 Gravid proglottids passed in stool in strands.of variable length - 2mm wide X 12-10size: mm long 4 (Broader/wider than longer Broad.)tapeworm with ccc centrally positioned, rosette-.shaped coiled uterus genital uterine pore at.center of proglottid 14Nov--23 NM Kaplan 22 Eggs :)Immature (unembryonated discharged in small intestine from up to ( gravid proglottids.)eggs/ worm/ day1,000, weeks after.infectionpass in feces yellow-brown, oval or ellipsoidal, :µm( with40-51x76-58( arrows) (At one end, operculum.w can be inconspicuous At opposite (abopercular) end, small knob w can be.barely discernible mature under appropriate.)days (conditions 14Nov--23 NM Kaplan *it called broad tapworm, because the gravid proglottid is broader than longer. * Tinea : uterus located medlateraly Diphelbothrium : uterus located centrally. 23 you should be familiar it pass immature, it need 2-3 weeks to become mature in appropriate condition Life cycle Dr read the slide برغوث : flea water الماء V.important infective stage : Plerocercoid larvae (mature larve) 7 P a g e

8 Diphylobothriasis Light infections: asymptomatic, nonspecific as loss of appetite, epigastric pain, abdominal cramps, vomiting, weight loss.some malnutrition & 12 Heavier infections: ccc vitamin B neurological &Megaloblastic anemia.problems Dr read the slide V.important specific ccc : decreament of Vitamin B12 in heavy infection by consumption of it 23-Nov-14 NM Kaplan 25 Dx Eggs & empty.proglottids in stool Rx.DOC: Praziquantel Control C for 10-Freezing at hours, thorough 48 cooking or pickling of. fish kills larvae Adequate sewage disposal to keep fish reservoirs free of.raw sewage Dr read the slide 23-Nov-14 NM Kaplan 26 Echinococcosis (Hydatid disease) Dr read the slide Causative agents: Echinococcus.granulosus & E. multilocularis 8 P a g e 23-Nov-14 NM Kaplan 27

endemic regions Dr read the slide * Epidemiology affected by hygene and geographics 23-Nov-14 NM Kaplan 28 smallest of all mm 9-3(tapeworms 3 long) with only.

9 Echinococcus granulosus common in Asia, Australia, Eastern Africa, southern Spain, southern parts of South America & northern parts of North.America per 1-2 incidence of human infection is population & higher in rural areas of endemic regions Dr read the slide * Epidemiology affected by hygene and geographics 23-Nov-14 NM Kaplan 28 smallest of all mm 9-3(tapeworms 3 long) with only.proglottids reside in small intestine of definitive & hosts; domestic wild carnivorous.)animals (dogs Adults * most important point smallest 14Nov--23 NM Kaplan 29 Eggs indistinguishable morphologically from. other Taeniid eggs 14Nov--23 NM Kaplan 30 9 P a g e

Hydatid cyst cm in diameter (although it may1-7 Round,.

only many larvae (protoscolices or hydatid.

µm 100 size -1.Ccc dagger-like hooklets Lt), (normally invaginated middle, then (& evaginate.

10 Hydatid cyst cm in diameter (although it may1-7 Round,.)cm30 grow up to consists of outer anuclear hyaline cuticula & inner nucleated germinal layer containing clear. yellow fluid Daughter cysts attach to germinal layer, although some cysts (brood cysts) may have only many larvae (protoscolices or hydatid.)sand 23-Nov-14 NM Kaplan 31 Fluid aspirated from hydatid cyst show multiple :protoscolices.µm 100 size -1.Ccc dagger-like hooklets Lt), (normally invaginated middle, then (& evaginate.rt) when put in saline Hydatid sand ** the most important lab diagnostic feature of is the presence of Dagger-like Hooklets 14Nov--23 NM Kaplan 32 Life cycle * the human is an accidentally infected ; if human is intermediate host, the cycle won't complete. because the human is the end stage of cycle. 10 P a g e

11 E.multilocularis In northern parts of Asia & North America. very similar morphology ( ) mm & )life cycle with the following differences :definitive hosts are foxes &,to lesser extent dogs, cats, coyotes & wolves ;intermediate hosts are rodents ;cysts are multilocular (many chambers) &larval growth (in liver (remains indefinitely in proliferative stage invasion of surrounding tissues * E.multilocularis is restricted geographical associated. Echinococcosis (Hydatid disease).causative agents: E granulosus & E multilocularis Symptoms of slow-growing tumor with eosinophilia, : depend upon location of cyst.large abdominal cysts increasing discomfort.liver cysts obstructive jaundice.peribronchial cysts pulmonary abscesses Brain cysts intracranial pressure & Jacksonian. epilepsy.kidney cysts renal dysfunction.release of contents of cyst anaphylactic responses 19-Nov-15 NM Kaplan 27 Dx Intradermal (Casoni) test using hydatid fluid. Radiology: for pulmonary cysts & calcified cysts. Serology: ELISA or indirect hemagglutination test for Abs against hydatid fluid Ags. ** injection of hydatid fluid Ags then looking for any skin reaction 11 P a g e 19-Nov-15 NM Kaplan 28

12 Rx surgical removal of cyst or inactivation of hydatid sand by injecting cyst with 10% formalin & its removal within few (4-5) minutes. Praziquantel: effective in many cases. Albendazole, in high doses,: alternative. Control Avoid contact with infected dogs & cats and elimination of their.infection *if there is resistance for Praziquantal surgery removal of the cysts 19-Nov-15 NM Kaplan 29 Rx R to praziquantel; doses of Albendazole has some anti-parasitic.effect Surgery to remove the.cyst Control.Rodent control *intermediate host Rodents * problem with hydrated cysts ;they are multilocular "many chambers" Hymenolepis nana 19-Nov-15 NM Kaplan 30 most common cause of all cestode.infections Worldwide. In temperate areas its incidence is higher in children &.institutionalized groups.reservoir: Rodents.Infection is by oro-fecal route 19-Nov-15 NM Kaplan P a g e

Adult worms cm, with small rounded scolex at 0.7X 1.5-4 Small.anterior end & proglottids at posterior wider end.

embryonated) (Mature immediately infective when. passed in stool days in 10>cannot survive. external environment Eggs round or slightly oval, smaller than those of H. diminuta, 40-60 X 30-50 µm.

Embryo (larva): Hexacanth oncosphere with six hooklets.

spread out between two membranes Life cycle 1 Arthropod intermediate host( various spp of beetles & fleas ingestion of eggs cysticercoids (IS) )humans or rodents ingestion of arthropod adults in

13 Adult worms cm, with small rounded scolex at 0.7X Small.anterior end & proglottids at posterior wider end.weeks 6-4resides in ileal portion of small intestine for 19-Nov-15 NMKaplan 32 released from gravid proglottids through its genital atrium or when proglottids disintegrate in small intestine embryonated) (Mature immediately infective when. passed in stool days in 10>cannot survive. external environment Eggs round or slightly oval, smaller than those of H. diminuta, X µm. with striated outer shell & thin inner membrane. The space between membranes is smooth or faintly granular. two poles, on inner membrane, from w 4-8 polar filaments spread out between two membranes. Embryo (larva): Hexacanth oncosphere with six hooklets. NM Kaplan 33 *Blue color : what Dr read from the slide *Red color : most important points ** the most important diagnostic feature of these eggs two poles on inner membrane from 4-8 polar filaments spread out between two membranes Life cycle 1 Arthropod intermediate host( various spp of beetles & fleas ingestion of eggs cysticercoids (IS) )humans or rodents ingestion of arthropod adults in small intestine. 2 Direct ingestion of eggs)is( )NO intermediate host :w hatch oncospheres w penetrate intestinal villus cysticercoids larvae w, upon rupture of villus,return to intestinal lumen, evaginate their scoleces, attach to intestinal mucosa & develop into adults. * Cross human-to-human infection(infective cycle with passage through external environment) in contaminated food or water or from fecally-contaminated hands. * Human infection might be accidentally by "beetles & flea " Or direct by "eggs ingestion " * infective stage : cysicercoid Internal autoinfection(infective cycle without passage through environment) persistence of infection for years 13 P a g e external

cramping.)anorexia &.Dx: eggs in feces.doc: Praziquantel.

diminuta NM Kaplan 35 Worldwide; cestode of rodents (frequently

Adults: 20-60 cm in length with slightly bigger eggs (with no

14 :C/P Light infections vague abdominal. disturbances Heavier infections diarrhea, (enteritis abdominal cramping.)anorexia &.Dx: eggs in feces.doc: Praziquantel.Control: Hygiene H. diminuta NM Kaplan 35 Worldwide; cestode of rodents (frequently found in rodents) but infrequently seen in humans. Adults: cm in length with slightly bigger eggs (with no polar filaments) & proglottids than H. nana. * you have to differentiate between H.nana & H.diminuta No-19 NM Kaplan 36 15v- Life cycle Dr Didn't read it 14 P a g e

Dipylidium caninum most common tapeworm infection in dogs & cats.

&rice-like bodies in stool motile upon release into.

cucumber tapeworm) with genital pores 2 ccc dipylos = two gates) (.

hexacanth oncosphere with 6 hooklets. round to oval (average 27-X 50-30 size.

15 Dipylidium caninum most common tapeworm infection in dogs & cats.in US :Adults Important slide NM Kaplan 38 Proglottids White, flat, amorphous &rice-like bodies in stool motile upon release into.environment small, can vary in size but longer than they are wide ccc barrel-shaped ( cucumber tapeworm) with genital pores 2 ccc dipylos = two gates) (.double-pored tapeworm Carmine-stain NM Kaplan 39 Egg s Embryonated & contain hexacanth oncosphere with 6 hooklets. round to oval (average 27-X size.)µm48 often found in packets, eggs vs. eggs 15-5with. of many cestode spp *embryonated = mature =ready to infection *diagnostic feature : eggs found in pockets 15 P a g e NM Kaplan 40

16 Life cycle Infection of humans, most often children, by ingestion of infected intermediate host (flea or louse) infective larval stages attach to small intestine.adults C/P Rx 19-Nov-15 Light infections: DOC: praziquantel. NM Kaplan 41 often asymptomatic. Niclosamide is also effective. Heavier infections: non-specific symptoms as weight loss, abdominal pain, & failure to thrive. Control examination & Rx of household pets. aggressive flea abatement. You are smart enough to notice that clinical presentation is the same for all worms 19-Nov-15 NM Kaplan 42 Helpful Table 16 P a g e

Helpful Table Trematodes Flukes one by one, so it

intercalatum *Dr:Important table and you need to

17 Helpful Table Trematodes Flukes one by one, so it s important *Some Trematods have more than one name in different regions of the world Exa: S.hematobium &S.intercalatum *Dr:Important table and you need to know these differences ; these are general lines and you will be asked about them 17 P a g e

Schistosomes 1intermediate host snail (vs.

hematobium in Africa. (S.intercalatum in SE Asia) -2 S.mansoni in Africa & America. -3S.

mekongi in central Africa) Various animals as dogs,cats,rodents,pigs,horses for S.

& goats, serve as reservoirs Adults reside in mesenteric venules in various locations.

18 Schistosomes 1intermediate host snail (vs.other trematodes with 2 intermediate hosts) restricted geographical distribution 3 spp.: -1S.hematobium in Africa. (S.intercalatum in SE Asia) -2 S.mansoni in Africa & America. -3S.japonicum in far east (S.mekongi in central Africa) Various animals as dogs,cats,rodents,pigs,horses for S.japonicum,and dogs for S.mekongi. & goats, serve as reservoirs Adults reside in mesenteric venules in various locations.specific for each sp) in humans( vs. other hermaphroditic(separate sexes :)trematodes.mm long with slender shape 20-7 : * marginal long folds2 slightly smaller with : *.is held forming (Gynaecophoric canal) in w ccc eggs w often contain fully-developed.mature miracidium when excreted 19-Nov-15 NM Kaplan 48 & schistosomes NM Kaplan 18 P a g e 49

19 S. haematobium Adult Eggs in section of bladder NM Kaplan 50 S. haematobium; Eggs -110X 65-55(large µm( in urine with 170 terminal spine at.posterior end.dd: S. intercalatum TERMINAL SPINE NM Kaplan 51 S. Mansoni & Adult in copula & Adult 19 P a g e NM Kaplan 52

20 S. Mansoni; eggs X large ( µm( in feces, with lateral spine near posterior end. Anterior end is.tapered & slightly curved LATERAL SPINE NM Kaplan 53 S. japonicum & Adult in copula & Adult NM Kaplan 54 S. japonicum; eggs -70X 65-55(smaller µm(, typically 100 oval or subspherical, vestigial ( with knob. spine) on side.dd: S. mekongi NO SPINE 20 P a g e NM Kaplan 55

Life cycle bifurcated-tail Cercaria Most important diagnostic feature NM Kaplan 57

occasional embolic egg granulomas in brain or spinal cord. Intestinal; (S.

21 Life cycle bifurcated-tail Cercaria Most important diagnostic feature NM Kaplan 57 Pathology Adult worms are innocuous & coat themselves with host Ags to evade immune responses. Deposition of eggs granulomata & fibrotic lesions of liver, bladder or other organs malignant changes: Urinary; (S. haematobium): Haematuria, scarring, calcification, squamous cell carcinoma, occasional embolic egg granulomas in brain or spinal cord. Intestinal; (S. mansoni & S. japonicum): Katayama fever, hepatic perisinusoidal egg granulomas, Symmers pipe stem periportal fibrosis, portal hypertension & occasional embolic egg granulomas in brain or spinal cord. 21 P a g e 05/04/2013 NM Kaplan 58

22 )Katayama syndrome)katayama fever.s. japonicum &Esp. by S. mansoni weeks after initial 3 as early as (Acute exposure) egg-laying phase of schistosomiasis, a toxemic syndrome in heavy primary infections, rarely seen in. chronic cases form of immune complex disease or serum.sickness-like condition Schistosomiasis )Bilharziasis) 05/04/2013 NM Kaplan million infected, 600 million at risk. Penetration of cercariae transient dermatitis (swimmers 'itch.( Symptoms are primarily due to reaction against deposited eggs In bladder :granulomatous lesions, hematuria & sometimes urethral occlusion. chronic infection in endemic areas most bladder cancers. In intestine: polyp formation w in severe cases dysentery. life threatening In liver :periportal fibrosis & portal hypertension HSM & ascites. Gross enlargement of esophageal & gastric veins (varices )rupture &hematemesis. S. japonicum eggs are sometimes carried to ) 1( CNS headache, disorientation, amnesia & coma ) 2( heart arteriolitis & fibrosis enlargement & Rt. ventricle failure Dx *ccc eggs Tests for viability of eggs* after Rx &Ova hatched in water motile miracidia seen by. hand-lens Eggs examined microscopically for ccc flickering movement flame of excretory. cells 22 P a g e Other serodiagnostic* tests.elisa for Ab detection.methods for Ag detection 05/04/2013 NM Kaplan 61

Generic Praziquantel DOC (effective.)against all spp.lack of toxicity.simple administration Rx Specific Metriphonate (organophosphate compound S.hematobium Oxamniquine S.

23 Generic Praziquantel DOC (effective.)against all spp.lack of toxicity.simple administration Rx Specific Metriphonate (organophosphate compound S.hematobium Oxamniquine S.mansoni 05/04/2013 NM Kaplan 62 Control Avoid contaminated water. sanitary disposal of sewage. destruction of snails. No vaccine is available. 19-Nov-15 NM Kaplan 63 Fasciolopsis buski (Giant intestinal fluke),adult; anterior end Adult carmine stain & endemic in central.southeast Asia.one year life span X 7.5-2elongate oval,.cm Lives attached to small intestinal mucosa of mammalian hosts pigs) &humans ( & inflammation, ulceration cesses 5 s 1N a ov b NM Kaplan P a g e

75-100 X 130-150 μm(. Immature eggs are discharged into intestine & passed in to mature & stool become embryonated in water. Eggs You need to memorize this slide *schistosome mature Buski immature.

24 X μm(. Immature eggs are discharged into intestine & passed in to mature & stool become embryonated in water. Eggs You need to memorize this slide *schistosome mature Buski immature. NM Kaplan 65 Life cycle Infection by ingesting water plants (water chestnuts) contaminated with encysted metacercaria w excyst in duodenum, attach to intestinal mucosa & mature into adults in days eggs passed in feces & hatch in fresh water miracidia w must penetrate suitable snail intermediate host within hours & undergo several developmental stages (sporocysts, rediae & cercariae) cercaria released in fresh water & encyst as metacercariae on acquatic.vegetations 19-Nov-15 NM Kaplan 66 C/P Light infectons: &epigastric pain, nausea.diarrhea, esp. in morning Heavier infections: generalized edema &. ascites Dx.Eggs in faeces Rx.DOC: Praziquantel Control Avoid water chestnuts from contaminated.waters Sewage ttt before. disposal 24 P a g e NM Kaplan 67

Heterophyes heterophyes (Minute intestinal fluke) Adult Middle East, &Far East. infects &lives in small intestine of humans, various fish-eating mammals (e.g., cats & dogs) &birds.

25 Heterophyes heterophyes (Minute intestinal fluke) Adult Middle East, &Far East. infects &lives in small intestine of humans, various fish-eating mammals (e.g., cats & dogs) &birds. one of the smallest, X mm. Adult stained with carmine oral sucker (OS), pharynx (PH), intestine (IN), ventral AC), & (sucker, or acetabulum.) eggs within uterus (UT NM Kaplan 68 Life cycle Infection by ingesting raw, undercooked or salted fish containing metacercariae w excyst, attach to mucosa of embryonated mature into adults & small intestine eggs (each with fully-developed miracidium) passed in feces, ingested by suitable snail (first intermediate host) & hatch miracidia released, penetrate snail s undergo several developmental stages (i.e. &intestine cercariae released cercariae) &sporocysts, rediae from snail & encyst as metacercariae in tissues of second intermediate (suitable fresh/brackish water fish.) host 19-Nov-15 NM Kaplan 69 C/P Intestinal main symptoms: diarrhea & colicky abdominal pain. Ectopic: eggs may penetrate small intestine mucosa, enter PB & migrate to extraintestinal sites as heart, liver, spinal cord & brain, where they can cause serious disease. 25 P a g e 19-Nov-15 NM Kaplan 70

Metagonimus yokogawai minute intestinal fluke Adult stained with carmine.

7 (PH), intestine (IN), genitoacetabulum (GA), ovary Mostly Far East,

within the uterus.spain (EG). Similar to H. heterophyes in.

26 Metagonimus yokogawai minute intestinal fluke Adult stained with carmine. - 1(smallest human fluke; oral sucker (OS), pharynx.).mm X 1.7 (PH), intestine (IN), genitoacetabulum (GA), ovary Mostly Far East, Siberia, (OV), large paired testes &Manchuria, Balkan states (TE), eggs within the uterus.spain (EG). Similar to H. heterophyes in. all aspects Metagonimus yokogawai ; another name for H.heterophys NM Kaplan 7 2 Liver flukes 26 P a g e

27 NM Kaplan 74 Fasciola hepatica )Sheep liver fluke(,adult: leaf.cm3 x1 shaped NM Kaplan 75 Eggs Embryonated eggs in µm, 150x 80 stool: indistinguishable from. those of F. buski NM Kaplan P a g e

Life cycle Humans infection by ingesting raw or undercooked fresh water plants as watercress w harbor encysted larval metacercariae w excyst in duodenum, penetrate through intestinal wall, migrate to

28 Life cycle Humans infection by ingesting raw or undercooked fresh water plants as watercress w harbor encysted larval metacercariae w excyst in duodenum, penetrate through intestinal wall, migrate to peritoneal cavity, penetrate liver capsule, wander through liver parenchyma for up to weeks & migrate into bile duct where it matures into 9 adult embryonated eggs in stool w hatch in water miracidia w penterate appropriate snail intermediate host & divide (sporocysts, redia & cercaria) cercariae w exit snail & encyst as metacercariae attached to acquatic. vegetations leaves 19-Nov-15 NM Kaplan 77 C/P Rx Praziquantel: NOT effective (vs. F. buski ),.Triclabendazole: effective NM Kaplan P a g e

29 Past year Questions : "these are what I can reach to and collect from PYQ" Which of the following can cause a true infection as well as an infection in humans a. Hymenolepis diminuta b. Hymenolepis nana c. Taenia solium d. Dipylidium caninum Answer: b Which of the following statements is correct about trematodes: a. All trematodes need 2 intermediate hosts b. Adult Schistosomes do not usually cause the tissue damage caused by schistosomiasis. c. A treatment with can treat the n already happened Schistosomal dermatitis & Acute schistosomiasis Answer: b Which of the following statements is correct: a. Some nematodes can live freely in nature or as human parasites Forgive me For any mistake Many thanks for my best friend Aya Duais <3 Al-Anoud Al-Bustanji 29 P a g e

Contains most of the medically important tapeworms Scolex has 4 suckers and compact vitelline gland are characteristic Range from mm to >10m

Cyclophyllidae Contains most of the medically important tapeworms Scolex has 4 suckers and compact vitelline gland are characteristic Range from mm to >10m Family Taeniidae Taenia saginata: beef tapeworm