Uf Parasitology Ex 3 kima

Generalized life cycle of flukes

• adult forms —> human hpsts

• where eggs located

• Cercaria → last dtage in intermediate host —> penetrate host immedatley or another stage?

Class Trematoda

Subclass Digenea

Superfamily Allocreadioidea

Genera: ParSo even though the genus SuperfFasciola or Fasciolopsis idea

Class Trematoda

Subclass Digenea

Superfamily Echinostomatoide

Genera: Fasciola, Fasciolopsis, Echinos Superfamily Opisthorchioidea

Genera: Opisthorchis, Clonorchis, Heterop Metagonimus

Intestinal flukes

• Fasciolopsis buski

• Heterophyes heterophyes

• echinostoma

Liver flukes

• Clonorchis sinensis

• opisthorchia viverrini

• Fasciola hepatica

Lung flukes

• Paragonimus westermani

F. buski- taxonomy

Class: trematoda → Subclass: diegenea → superfmaily: Echinostomatoida → Genera: fasciolopsis

Fasciolopsis buski

• Small intestines, sometimes colon

• larger flukes → 20-75mm by 20mm width

• ventral/ oral sucker —> adhere to surfaces; intestinal wall

• NO cephalic cone

• Caeca lack side branches

• Aquatic FRECH water —> fresh water snails 

• PIGS → 2nd def host

F. Buski- life cycle

• adult worms live in Sm. int— > produce eggs (enemboryated, need more devlo) —> found in water and hatch into MEracidea → infect snail host: Segmentina/Hippeutis —> in snail: sprocuts → radiae →Cercariae at 30-40 days after infection → relesae into envrioment→ attach to aquatic plants → water chestnut/bamboo—> metacercarie on aquatic plants → human injest metacercarie —> take 3 months to show symptoms —> produce 25,000 eggs daily

• Eggs —. miracidium → [IH]sprocyts → redia → cercaria → metacercaria pon vegetation → [DH] adult flukes → eggs

Fasciolopsis buski- epidemiology 

• Distirbution: easter/southern Asia, Korea to India 

• 4-23 yr olds

• PIGS —> resrvoir, pig farming, close interactions w/pigs

• about 100 mil infections w.w.

F. buski- pathogenesis

• Suckers; rub on intestinal wall -→ attach to intesitnal mucos, localized inflammation 

• Someimes ulceration of gut wall —> malabsorbtion

• stasis/ obstruction when many worms present 

• may have several thousand present

• chronic diarrhea may kill host —> malabsorbtion

• children - Edem of face/ torso

  • Toxin: not sure; sorta

F. buski- diagnosis

• fecal sedimentation → large eggs w/ small indistinct operculum → 67-181 by 43-95 mm

• eggs identical to F. hepatica

• worms passed in feces/ vomited

F. buski- prevention

• fully cook aquatic oplants in endemic areas, those grown in ponds using human/swine feces as fertilizer

• immerse vegtables in boiling water for few seconds

• deowrm DEFINITVE host —> humans/ pigs

E. capromi, trovolis, hostensi, revolutum - taxonomy

Class: Trematoda → Subclass: Digenea → Superfamily: Echinostomatoidea → Genera: Echinostoma

Echinosotmes- general

• aproni, trovolis, ostensi, revolutum

• spiny-collared worms 

• circumoal collar/ peglike spines

• large acetabulum —> above parasite midline

• eggs—. UNEMBRYONATED, hatch in water

• Snail host: Lymnae spp., SEGMENTINA (1st intermediste snail host)spp., Biompalaria spp.

• METACERCARIA → second intermediate hosts snails, FROGS

  • eat frog legs

Echinostomes- epidemiology

• Southeast Asia, Taiwan, Indonesia

  • found w.w.

• Metacercariaie → excyst duodenum

Echinostomes- pathogenesis

• Sharp-spined collare of ADULTS → irritation of intestinal mucosa

• Inflammation at site of attachment

• heavy worm burdens caused → anemia, malnutrition, ntestinal perforation 

• Operculum —> eggs; DIAGNOSTIC

heterophyids general

• fully embroyonated eggs

• tiny 1-2 mm long —. flukes live in small int of people —> body covered w/ scales

• Acetabulum

• Gonotyl: prominent sucker around genital pore

heterophyes- distribution 

middle east, spain, eastern asia, russia,brazil

DH → canids, felids, people, pelicans, water birds

• metagonimus lack a genital sucker/gonotyl

• unarmed ventral sucker

Metagonimus yokogawai- distribution

• philipines, asisa, eastern india, ukraine 

• DH dogs, cats, pelicans, water birds/humans 

Metagonimus yokogawai- infective host

first —> Semisculcospira snail

second —> Salmon 

Metagonimus/heterophyes- pathogenesis/ symptoms

• adults invade/erode, mucosa

• eggs deposited into mucosa —. enter lacteals/venules, carried to other parts in host

• light infection —> no issues

  • diarrhea, abdominal pain

• Heavy infection 

  • bloody diarrhea, petechial hemorrahgse of submucosa

  • heart —. heterophyid myocarditis in philippines

• eggs carried to heart → vessels of heart become congested → heart attacks

metagonimus/heterophyes- diagnosis

• fecal sedimentation

• eggs similar to clonorchis sinensis

metagonimus/heterophyes- treatment

• praziquantel 

metagonimus/heterophyes- prevention

• cooking fish in/from endemic areas

• dewormers in DHs

F. hepatic- taxonomy

Trematoda -. digenea -. echinostomatodiea → fasciola

Fasciola hepatic- general

• adults- . bile ducts

• large up to 40 mm by 13 mm

• cephalic dones -. w/ oral sucker/ ventral sucker (Acetabulum) at base of cone

• scalelike spines on tegument 

• intenstinal ceca/ testes → highly branches

• mainly → domesitc ruminants → herbivores → sheep/cattle 

• Zoonotic 

• Semiaquatic snails

• Encycts on vegetation 

Fasciola hepatic- distribution

• ww. spotty tho

• sheep./cattle— . Sothern france, North africa

• C/S America —> boliviam ecuador, 

• USa: Florida, southern MMiss drainagem NW states, Cali (in animals) 

• rabbits

• major infect → 

Fasciola hepatic- lifecycle

• eggs → miracidum → sporocyt → redia ! -. redia Ii → cercaria → metacercaris on vegetation → adult flukes → eggs

• unembroynaed egg passed trhu feces -. embryonaed eggs in water → miracidai hatch, pemnetrate snail →in snail morphs into sporocysts to redaie to cercarie → free swimming cercarei encyst on water plants → metacercareiae on water plant ingested by human,sheep, cattle → encysts in duodenum → adults in hepatic billary ducts —> pass into feces unemrboynated eggs

Fasciola hepatic- pathogenesis

• immature flukes penetrate intestninal wall, migrate thru liver parenchyma → destroying as moving 

• liver tissue- . fibrotic 

• Blood → consumed/ anemia 

• Bile ducts → hypertriphy of uct lining/ calcified 

• Abscesses form/ spill into parenchyma 

Fasciola hepatic - symptoms

• intesne headce, fever, back ache

• enlarged tender liver, diarrhea, anemia, jaudice, cholangitia 

• epigastric pain, anorexia, weight loss

• Chornic cases —> years 

• profuse anemia —> ulceration of bile ducts 

• Ectopic sites- > abscess/ulcers develop from migrating juveniles/ some adults

  • inner eat, eye, lung, intestinal wall, spleen, pancera, skeletal muscle,protal veins

• eggs passed from ingestig raw animal liver

Fasciola hepatic- diagnosis

• ingesting watercress

• fecal sedimentation/ finding characteris eggs

  • Yellowish, operculate, size: 130-150 by 65090 

• operculum _. not obvious, egg countines curve on perculaute end

Fasciola hepatica -prevention

• dont eat watercress in endemic areas

• watch out for grass blades put in mouth/chew on in contaminated pastrues 

• control primary hosts → ruminats by strategic deworming 

Fasciola hepatic- treatment

• bithionol 930-50 mg/kg for 10-15 doese

• Triclalbendazole → targets worm tubulin 

• cattle/sheep → clorsulon/ albendazole

• NO praziquantel → ineffective 

C. Sinensis

trematode → diegena → opisthorchioidea → clonorchia

Clonorchia sinensi - general

• priental/chiense liver fluke

• adults in bile ducts

• sldender fluke 25×5

• oral sucker slightly bigger than acetabulum

• mo spines on tegument 

• 2 larger braches testes in posterieer end of fluke

• humasn rpimary DG 

• 2 dh _. fish eating carnivores → canids/felines

• aquaitc snails at first IH —> eggs hatch in snail 

• Metacercaria → CYprinidae → grass carp -./ crayfish 

Clonorchis sinensi - life cycle

• eggs → miracidium 0> sporocyts → redia → cercaris thru skin of fih → metacercarias in fish muscle -. adult flukes → eggs

Clonorchia sinesines → distribution

• japan, china, korea, tawiwan

• high preanaes in chinese immigrants

• 505 prevenalse in some areas

• pifs, cats, dogs, rats

Clonorchis sinensis- pathogenesis

• Dose related → more parasites more damafe to host

• 6,000 been removed from 1 human liver ‘immature flukes- . ener common bile duct establich infection 

• less damge to parenchyma due to NO migration 

• bile ducts very dialted/ walls thickened w/ accompyaning fibrosis 

• gall stones containing adults/eggs 

Stages of clornorchiasis

• early: fever, esinophili, gastric pain

• 2nd: diarrhea, anorexia, liver tendernes, vomiting, intermittent jaudince, progressive hepatomelay, prolonges low grade fever, 

• Advanced: cirrhosis of liver, ascites, anasarca, cachexia, extreme jaudice, cholonagipocarcinoma (common in men)

Clornorchia sinenses - eggs

• matrue upon release

• distictive operculum

• knob at abopercular end 

Chlonorchia sinesis - diagnosis

• fecal sedimentation, small eggs, not symetiracal ,Obviosu perculum at smaller end, usually knob at end away from perculum, end w/ perculum not smooth curve 

• egg contains miraidium when passed from host

Clonorcia sinesnsis- treatment

• Praziquanrel → 2 days is best

• older drugs dehydrodroemtine/miclofolan → cause dizziness, weakness, pain

Clonorchia sineses -prevention

• dont eat poorly cooks, steamd smoked, pickled, raw dish in enedmic areas

• treat 2nd host in peridoemstic situation → cats/dogs

• rural problems → honkong only 18%, rural 80%

• 20/30 yrs old →75 %, 90%

O. viverrini- taxonomy

trematoda- dignea - opisthorchioida - opisthorchis

Opisthorchia v/s- distribution

• asai, S/C/E europe, russia turkey 

Opisthorchia viverrini - life cylce

• Eggs → bithymis spp. snail → miracidium → sporocysts → redia -. cercaria _. 2nd IH Cyprinid fish, fresh water → metacercaria → resovier host (dogs/cats) =→ DH humans → attach to bile ducts/liver

Opisthorchia felineus/ viverrini- general

• adults in ble duct

• eating fish 

• S/E/C/ euope —. turkey, russia, Vietnam, india, puertotico, caribean island 

• diarrhea, thickening / eventuall erois of bile duct wall 

• Snail: Bithymia

• Fish host: cyrpinidn fishses

• felines → important reservoir hosts

Hypothsises pathway that leads to cholangiocarcionma

• cellular modification → ROI, No

• no DNA repair/Apoptosis

• Fixed genetic alterations → Malignancy

• DNA damage

• Would repaird always active → Altered cell states

P. westermani - taxonomy

trematoda - digena- Allocreadiodiea → paragonimus

Paragonimus westermanu - genreal

• adults live in pairs

• pairs encapsulated in lung parecnhyma

• ectopic in brain

• medailly located ventral sucker

• 7.5-12 mm long 

• tegument covered w/ scale-like spines

• reddish brown '

• parasites of people, candid, felids 

• zootonic 

• 1st Ih -0> squatic snail 

• 2nd Ih → freshwater crabs/ crayfish 

Paragonimus westermani - distribution

• P. westermani → Asai, russia, phillipines

• P. afrticanua → wester, sub-sarahn africa

• P. mecianus 0> S/C america 

• P. kellicotti → USA, fogs, cats, peopl,m crayfish —> intermiedtaed host common 

• ‘Carnovores → cats.dogs -. more signifcnat DH

Paragonimus westermani - life cyle

• Unembriyonated eggs → emboryonate in water → miracidia hatch/penetrate snail Semisulcospira → sporocysts → rediae -. cercaria → cercarieae invade cruststean -< encts into metaC. → jhumans eat infefectes → encysts in duodenum → adults migrate to lungs/lay eggs OR swallowed/pased w/stool

Paragonimus westermani - interemediate hosts

• Semisc=ulcospria kurodai

• Asain freshwater crab species

• crayfish of oronectes species → Mississippi riber drainges basin 

Paragonimus westermani - pathoegenesis

• abscess formaton → trapped migration stimulated

• pair of adults in lung parenchyma → induce inflammation leading to encapsulation by fibroud connective tissue

• Cyts → up to 2 c, in diameter, capsule swells/ruptures releaseing eggs/blood 

  • in contact w/ bronchioles 

• not more than 20-25 worms/person 

• some into in brain/ skin

Paragonimus westermani - clinical signs

• chronic brochitis w/ brownish/reddish sputum, hemoptysis, fatigue, penumothroax, exercis dyspnea, lung absesses may form, abdominal pain may devlop

• radiographs - cloudy infiltrated/ nodules in lungs,

• darrhea, naues

• Cerebral paragonimiassi → ectopic forms lodge in bain → meningitis, seizures retardation headches, paresis, coma

Paragonimus westermani - diagnosis

• fecal sedimentation/ finding characterictsi of egg

  • goldne brown, prominet operculum/ measure 80-120 by 45-70 microns

  • shoulders where operuculum is attached/ thick walls

• coughed up in sputum/ swallowed, eggs in bloody sputum for confirmation of diagnosis

Paragonimus westermani - prevention

• fully cooking all fresh water crabs/vrayfish

• treating all DH to elimated egg source

Paragonimus westermani - treatment

• Praziquantel; 1 single day 

• much more effective w/ few

Schistosoma- taxonomy 

Trematoda → digenea → schistosomatodiea → generae: ____(blood flukes)

Schustosoma japonicum- general

• veins of small intestines

• terminal soine in eggs —> barely visible 

• prepatent period: 5-6 wks in humans; 4-9 in snails

• like expectancy up to 30 years

S. japonicum - distribution

• ages: 10-25 yrs

• China, indonesia, philippines, SE asia

Schistosoma haaaematoblium- general

• urinary bladder veins, 

• eggs —. terminal spine

• prepatent period: 10-12 wks in humans; 4-6 wks in snails

• up to 30 yes adult fluke expectany

S. haematobium - distribution

• africa, Middle east

Schiostosoma mansoni- general

• portal veins drain lg int

• egs lateral spine

• prepatenjt period: 7-8 wks in humans, 3-4 wks in snail

• adult life expectanty up to 30 years 

S. mansoni- distribution

• africa, S america, caribbean

• 50% of some local populations

• 10% of world population

S. mekongi- general

• determined to be different form S. japonicum 

• very similar eggs t

S. mekongi- dis

SChistosoma spp. - general

• adults in veins of DH

• seperaet sexes —> In copula 

• males: gynecophoral cnala —> females reside; strong oral sucker

• Intestinal ceca → fuse midpt of worm then countine as single gut to posterior

• Schistosome eggs → NO OPERCULA 

• freswater snails → IH

• no redial stage

• Cercariae penetrate intact skin 

Schistosoma spp. - life cycle

• eggs →(IH) miracidium → (IH)sporocyst → (DH)cercaria penetrate skin → (DH)adult flukes -.>(DH) eggs 

• cercariae enter thru skin → lose tail → shed surface coat -< become schistosomule 

• ,move into capillary bes, feed on RBC

• grow RAPIDLY in lungs 10-14 days 

• transporterd to heart then pulmonary capillaries, back to heart then to circulation including helatic portal veins to liver to mature sexually/couple 3 weeks

• couple migrate against blood flow to peritonea veins of int. and urinary bladder

• prepatnet period - 5-12 weeks

• host cytokines (TNF) —. stimulate egg production

• flukes appear incorporate host proteins into glycocalyn in schistosmule stage; able to HIDE erthyrocyte glycoproteins, MHC molecules

S. japonicum - IH

• oncomelania hupensis

S. haematobium- IH

• Buliuns trunxattus

• bulinus africansus

S. mansoni- IH

• biomophalaria pfeifferia

• biompharia alexandria

S. intercalatum- IH

• Bulinus forkskalii

S. mekongi- IH

• neotricula operta

Schistosoma spp.- symptoms; inital phase

• inital pahse: localized dermatitis from penetration of cercariae

• local edema at 4 days

Schistosoma spp.- migration phase

• 14-84 days

• Kataymama syndrome

• fever, headache, myalgia, diarrhea, respiratory sympomts

• pulmonary congestion

• lungs —> Liver

• hepatic portal veins to mesenteric veins of intestine/urinary bladder

SChistosoma spp. - intermediate phase

• 2 months → several yrs 

• classic sign of urogenital schistosomiasis → haematuria 

• kidney damage/ fibrosis of bladder/ ureter —> diagnoses in advanced cases

• womne: urogeneial; schistosomiasis presnet w/gential lesions, vaginal bleeding, pain during sex, nodules in vulva, 

• men: urogenital schistosomiais, induce pathology of semincal vesciles, prostate/other organs,

• diseaes long-term irreversible consequences —> infertility 

Schistosoma spp. - chronic phase

• sever intestinal, renal, hepatic pathology —> host response to migrating eggs

• eggs lrimary cause of pathology

• hepatomegaly/ splenomegaly 

• granulomas around single egg/clusters of eggs occlude vessels leading to necrosis

• granulomas —> result of host response

• S. haematobium —> bladder cancer

S. haematobium- patho

• male max 15 mm; female max 20 mm

• 30 eggs/day, laid singly 

• several speices of 3 genera of snails are IH, Bulinus most widespread

• adults live in vessles of URINARY BLADDER and genitals

• reservioirs RHas → sheep, pis, monkeys 

SChistosoma haematobium- life cylce

• eggs terimanl spoike released into water → eggs hatch in watcher → mircarida poenetrate snail → cercaireai leave snail → cerariae enter skin → aschistoosomulate migrate to liver -. adults mate in livewr → migrate to bladder as couple -. adults live in venous plexus of bladder → eggs pass into urine then water supplies

S. mansoni- patho

• mle max 10 mm and female max 14 mm

• Males → tubuerculations

• 190-300 eggs/day, single 

• Mainly biophalaria as IH

• reservoirs DHs: cattle, sheep, dogs, rates, some primates, other wildlife 

• cause GUT POLYPS 

S. mansoni- life cycle 

• eggs hatch in water → mircacida penetrate snail -. cercaira leave snail → cercariare enter skin → schistosomulae migrate to liver → afults mate in liver → migrate to mesenteris -< live in mesenteric venules → eggs pass into sm int. → eggs pass into feces -. eggs depoites in water thru feces 

S japonicum - patho

• males max 20 mm/ females max 26 mm

• 3500 eggs/day, clusters —. cerebral granulomatostous lesions

• sanils of genus : ONOCOMELANIA are IH

• males NO TUBERCULATIONS

• resivor RHS: cattle, dogs, pigs, wild rodens, macaques, vaireuty of wildlife 

S. japnoumc- life cycle

• eggs in water —> mircaidum infect snails -. cercaries leae snail -. cercaire penetrate skin p schistomulate migrate to liver → adults mate/ mature → migrate to mesneteris —> eggs pass into sm inte then passed in feces into water OR cause CNS damne, hepatosplemnomegaly, Cor pulmonale 

SChistosoma spp. -diagosniss

• characteris eggs in feces/ urine and tissue biopsies

• chronic cases few eggs passed b/c eggs cannot get out of host —> bippies’immunologic tests need confirmation of eggs 

Schistosoma spp. - treatment

• Prazi

schistosoma - immunity

• macromolecule immunogens relased by eggs → migratio naid

• migratory juveniles release molecules from acetabular glands; shed tegument

• flukes appear to incorpoarte host proteins into glycocalyx in schistosomule stage

• decay accelrating factor found on surface of schistoomes; schistoomes express CD59-like molecyles

• cercarial/ schistosomule surdace AG differnet

• TH2 response iil-10 —> predominare schistoomse infection

Swimmers itch 

• cercariue avaina schistosomes released into fresh water lakes/ seashores when people swim/wade, skin penetrated

• cercarie not able to enter blood vessles/mature

• cercareis skilled by immune systme -. rxn stronger after first challenge

• killed cercariae cuase pruritus/ excessive itching

Cestoidea - general

• tapeworms

• lack mouth/digestive tract

• 25 m long

• multi-segmented

• Scolex: anterior end functions in attachment

• Neck: narrowesr part of worm 

• strobila: made up of segments of worm called → PRoglottids 

• very well-developed nervous system; unmyleniated, numerous neuropeptides, reproductive organs/musculatrue proglottids innervated

SColex- cestodes

• Acetabulat: 4 suckers/ msucular cups,

  • Armed/hooked rostellum

• Bothriate: 2,4, or 6 longitudinally arranged shallow depressions

Tegument- cestodes

• lined w/ microvilli

  • Glycocalyx/ microthrices

• nutrient aborbtion

• tegumental/ parenchymal musculature → circular/ lomgitudinal msucles

• Parechyma: space enclosed by tegument 

osmoregulatory/ excretory sytem- cestodes

• collecting canals( ventral from scolex, dorsal to solex,

• flame cell/protenephridia present for excretion of waste

Reproducitve- cestode

• proglottid —> male/female organs

• proglottids on same worm/another worm can mate

• Anapolytic owmrs: Diphylloborthium; tanned eggs exist thru uteruine pore

• apolytic worms: entire gravid proglottid released; n o uterine pore; dipylidium 

Egg- cestode

• encased in shell

• layered

  • outer envelope

  • embryophore

  • inner envelipe

  • oncosphere: embryo equipped w/ hooks and will give rise to larval form, contain vitteline cells as food source

psudeophyllidean - cestodes

• eggs tanned, ciliated embryophore, operculu, 1 end, 

• from w/in oncosphere a coracidium emerges 

Diphylidean- cestodes

• eggs thin shelled,

• relativley thick outer envelope/ non-ciliared embryophore

taenoid- cestodes

• eggs lack shell/outer envelope

• embryophore outermost covering 

Pseudophyllidean pattern- life cycle

• eggs released trhu uterine pore expelled in feces

• coracidia emerge/ swim around in water

• coraciddia inget by aquatic arthropod devlop to proceriod

• crustaceasn is eaten by vertebraee, larvae migrate/ differenetiate w/in tissue muscle into plercercid → beings strobilization 

• plercercoid infective to humans; attach to walls of sm int 

• D. latum 

Cyclophyllidean pattern- life cycle

• eggs relased in gravid proglottid

• eggs hatch in digestive tract of IH —> arthorpods for some species/vertebraes for others 

• invertebrate hosts → oncosphere enters hemocoel/ metamophoses into cysticercoid

• in DH cysticercoid released/ attaches to intestine

• vertebrae hosts → oncosphere penetrates int wall/ carrie to tissue/muscle → then develops into cysticercus/ other larval form

• larval forms have scolex invaginated in fluid filled vescile