Trematodes

TREMATODESTREMATODES

Prepared by FZHapanPrepared by FZHapan

CHARACTERISTICSCHARACTERISTICS Dorso-ventrally flattenedDorso-ventrally flattened UnsegmentedUnsegmented Leaf-likeLeaf-like Hermaphroditic except blood flukesHermaphroditic except blood flukes Two radially striated suckersTwo radially striated suckers Incomplete digestive tractIncomplete digestive tract Adults are covered with spines, exceptAdults are covered with spines, except Incomplete digestive tractIncomplete digestive tract Most of the body is occupied by reproductive Most of the body is occupied by reproductive

organsorgansPrepared by FZHapanPrepared by FZHapan

BLOOD FLUKESBLOOD FLUKES


BLOOD FLUKESBLOOD FLUKES CharacteristicsCharacteristics

– DioeciousDioecious– Males are shorter and stouter than femalesMales are shorter and stouter than females– Lateral margins of males are folded ventrally to form a Lateral margins of males are folded ventrally to form a

gynecophoral canal in which females are receivedgynecophoral canal in which females are received– Suckers are armed with delicate spinesSuckers are armed with delicate spines– There is no muscular pharynxThere is no muscular pharynx– Eggs are non-operculatedEggs are non-operculated– Eggs are fully embryonated when laidEggs are fully embryonated when laid– Embryonated eggs have a ciliated embryo called Embryonated eggs have a ciliated embryo called

miracidiummiracidium– Cercariae have bifid tailsCercariae have bifid tails– There is no encysted metacerciarial stageThere is no encysted metacerciarial stage– Infective Stage: cercaria penetrating the unbroken skinInfective Stage: cercaria penetrating the unbroken skin


BLOOD FLUKES: BLOOD FLUKES: SchistosomesSchistosomes SchistosomesSchistosomes

– Schistosoma japonicumSchistosoma japonicum : Oriental : Oriental blood flukeblood fluke

– Schistosoma haematobiumSchistosoma haematobium: Vesical : Vesical blood fukeblood fuke

– Schistosoma mansoniSchistosoma mansoni: Manson’s : Manson’s blood flukeblood fluke


Life Cycle Life Cycle


Schistosome Schistosome MiracidiumMiracidium MiracidiumMiracidium

– Hatches from the egg Hatches from the egg in slightly alkaline in slightly alkaline clean water with a clean water with a temp. between 25 temp. between 25 00C C to 31to 3100CC

– Free swimming cilated Free swimming cilated embryo liberated from embryo liberated from the eggthe egg

– PhotacticPhotactic– Infect snailsInfect snails


Schistosome Schistosome Sporocysts and Sporocysts and CercariaCercaria Mother sporocysts Mother sporocysts

develop from develop from miracidium within miracidium within the snailthe snail

Daughter sporocyst Daughter sporocyst develops from develops from mother sporocystmother sporocyst

Cercariae develop Cercariae develop from daughter from daughter sporocystsporocyst


Schistosome CercariaSchistosome Cercaria CercariaCercaria

– Emerges from Emerges from daughter daughter sporocystssporocysts

– Escapes from the Escapes from the snailsnail

– Has a body and a Has a body and a forked tailforked tail

– Infects man by Infects man by skin penetrationskin penetration


SchistosomulaeSchistosomulae SchistosomuleSchistosomule

– Develops from cercaria Develops from cercaria after skin penetrationafter skin penetration

– Adapted to survive in Adapted to survive in serum or physiologic serum or physiologic saline at 37 saline at 37 00CC

– Enter the pleural Enter the pleural cavity---diaphragm---cavity---diaphragm---peritoneal space---peritoneal space---penetrate the liver to penetrate the liver to reach the intrahepatic reach the intrahepatic portions of the portal portions of the portal veinvein


Schistosoma Schistosoma japonicumjaponicum Schistosoma Schistosoma

japonicumjaponicum– Life cycle involves Life cycle involves

alternating parasitic alternating parasitic stages in mammalian stages in mammalian hosts and free living hosts and free living stagesstages

Egg and miracidiumEgg and miracidium First stage (mother) First stage (mother)

sporocystsporocyst Second stage Second stage

(daughter) sporocyst(daughter) sporocyst cercariacercaria SchistosomulumSchistosomulum Adult schistosomeAdult schistosome



japonicumjaponicum– Primarily parasites of Primarily parasites of

the portal vein and its the portal vein and its branchesbranches

– Each female fluke Each female fluke deposits 500-2000 deposits 500-2000 immature eggs/dayimmature eggs/day

– Embryonation takes Embryonation takes place within 10-12 place within 10-12 daysdays

– Eggs escape through Eggs escape through ulcerations in the ulcerations in the intestinal lumen and intestinal lumen and are passed out with are passed out with the feces the feces



japonicum japonicum in in eternal copulaeternal copula– Males have a Males have a

gynecophoral gynecophoral canal which canal which receives the receives the female during female during copulationcopulation



japonicum japonicum OvaOva– Ovoidal, rounded or Ovoidal, rounded or

pear-shapedpear-shaped– Thin shellThin shell– Pale yellowPale yellow– Curved hook or spine Curved hook or spine

or lateral knobor lateral knob– Laid in the Laid in the

multicellular stage multicellular stage and embryonte within and embryonte within 10-12 days10-12 days


Schistosoma mansoniSchistosoma mansoni

Schistosoma Schistosoma mansoni mansoni male male and femaleand female– Female inside the Female inside the

gynecophoral gynecophoral canal of malecanal of male


Schistosoma haematobiumSchistosoma haematobium

Schistosoma Schistosoma haematobium haematobium adultadult


Schistosoma haematobiumSchistosoma haematobium

Schistosoma Schistosoma haematobium haematobium ovaova– Note the Note the

presence of presence of terminal spineterminal spine


Differentiating Differentiating Features of Features of SchistosomesSchistosomes

FeatureFeature S. japonicumS. japonicum S. mansoniS. mansoni S. S. haematobiumhaematobium

Testes Testes (male)(male)

6-7 in a single file6-7 in a single file 8 -9 in a zigzag row8 -9 in a zigzag row 4 -5 in groups4 -5 in groups

Ovary Ovary (Female)(Female)

In the middle of the In the middle of the body; contains 50 or body; contains 50 or

more eggsmore eggs

Anterior to the Anterior to the middle of the body; middle of the body; contains 1-3 eggscontains 1-3 eggs

Behind the middle Behind the middle of the body; of the body;

contains 20 – 30 contains 20 – 30 eggseggs

IntestineIntestine shortshort longestlongest longlongEggEgg Lateral knobLateral knob Lateral spineLateral spine Terminal spineTerminal spineIntermediate Intermediate HostHost

OncomelaniaOncomelania Biomphalaria and Biomphalaria and AustralorbisAustralorbis

Bulimus (Physopsis)Bulimus (Physopsis)

Definitive Definitive HostHost

Man and domestic Man and domestic animalsanimals

ManMan ManMan


Blood Flukes: Blood Flukes: Pathogenesis and Clinical Pathogenesis and Clinical ManifestationsManifestations SchistosomiasisSchistosomiasis Host granulomatous reaction to eggsHost granulomatous reaction to eggs Pneumonitis due to schistosomula in Pneumonitis due to schistosomula in

the lungsthe lungs Hepatosplenic diseaseHepatosplenic disease Colonic schistosomiasisColonic schistosomiasis Cerebral schistosomiasisCerebral schistosomiasis


Blood Flukes: Blood Flukes: SchistosomiasisSchistosomiasis

Distended belly is one of the symptoms of schistosomiasis


Blood Flukes: Blood Flukes: DiagnosisDiagnosis

SchistosomiasisSchistosomiasis– Eggs may not be demonstrable in Eggs may not be demonstrable in

the fecesthe feces

– Infections where there is scarring Infections where there is scarring prevent passage of eggs into the prevent passage of eggs into the intestinal lumenintestinal lumen



SchistosomiasisSchistosomiasis– Stool Examination TechniquesStool Examination Techniques

Merthiolate-Iodine Formlin Concentration Merthiolate-Iodine Formlin Concentration Technique (MIFC)Technique (MIFC)

– Sensitive for moderate and heavy infections Sensitive for moderate and heavy infections – Not adequate for light infections (less than 10 Not adequate for light infections (less than 10

eggs/gram of stool)eggs/gram of stool) Kato KatzTechniqueKato KatzTechnique

– For enumeration of eggsFor enumeration of eggs– Most commonly used for evaluating Most commonly used for evaluating

epidemiology, effect of control measures, drug epidemiology, effect of control measures, drug trialstrials



SchistosomiasisSchistosomiasis ImmunodiagnosisImmunodiagnosis

– Intradermal tests for immediate cutaneous Intradermal tests for immediate cutaneous hypersensitivity using adult worm extractshypersensitivity using adult worm extracts

– Indirect hemagglutination using adult worm Indirect hemagglutination using adult worm and egg antigensand egg antigens

– Circumoval precipitin testCircumoval precipitin test– Enzyme-Linked Immunosorbent Assay Enzyme-Linked Immunosorbent Assay

(ELISA) using soluble antigens of adults and (ELISA) using soluble antigens of adults and eggseggs


Blood Flukes: Blood Flukes: TreatmentTreatment TreatmentTreatment

– Praziquantel Praziquantel (heterocyclic (heterocyclic prazinoisoquinoloprazinoisoquinolone compound)ne compound)

– Single dose of 40-Single dose of 40-50 mg/kg50 mg/kg

– 25 mg/kg in two 25 mg/kg in two dosesdoses

– 20 mg/kg in three 20 mg/kg in three dosesdoses


Blood Flukes: Blood Flukes: EpidemiologyEpidemiology

In the PhilippinesIn the Philippines– 24 endemic provinces24 endemic provinces

SorsogonSorsogon Oriental MindoroOriental Mindoro SamarSamar LeyteLeyte BoholBohol All provinces in Mindanao except All provinces in Mindanao except

Misamis OrientalMisamis OrientalPrepared by FZHapanPrepared by FZHapan

Lung FlukesLung Flukes


Lung FlukesLung Flukes Paragonimus westermaniParagonimus westermani Oriental Lung FlukeOriental Lung Fluke

Paragonimus philippinensisParagonimus philippinensis Paragonimus siamensisParagonimus siamensis (cats) (cats)


Lung Flukes: Lung Flukes: Paragonimus Paragonimus westermaniwestermani Paragonimus westermani Paragonimus westermani

adultadult– HermaphroditicHermaphroditic– Body covered with Body covered with

spinesspines– Reddish brownReddish brown– Measures 4-6 mm in Measures 4-6 mm in

width and 3.5-5 mm in width and 3.5-5 mm in thicknessthickness

– Resembles a coffee Resembles a coffee bean bean

– Adult worms are found Adult worms are found in pairs or in threes in in pairs or in threes in fibrotic capsules or fibrotic capsules or cysts in the lungscysts in the lungs


Lung Flukes: Lung Flukes: Paragonimus Paragonimus westermaniwestermani Paragonimus Paragonimus

westermani westermani ovaova– Yellowish brownYellowish brown– Thick-shelledThick-shelled– Operculated with a Operculated with a

thickened thickened abopercular eggabopercular egg

– May be seen in the May be seen in the sputum or in feces sputum or in feces if the sputum is if the sputum is swallowedswallowed


Lung Flukes: Lung Flukes: Paragonimus westermaniParagonimus westermaniLife CycleLife Cycle


Lung Flukes:Lung Flukes:Epidemiology of ParagonimiasisEpidemiology of Paragonimiasis

First Intermediate HostFirst Intermediate Host– Brotia asperataBrotia asperata (snail) (snail)– Where miracidium develops into 1 Where miracidium develops into 1

sporocyst and 2 redial stages of sporocyst and 2 redial stages of developmentdevelopment


Lung Flukes:Lung Flukes:Epidemiology of ParagonimiasisEpidemiology of Paragonimiasis

Second Intermediate HostSecond Intermediate Host– Sundathelpusa philippina Sundathelpusa philippina oror

Parathelpusa grapsoides Parathelpusa grapsoides (former (former name)name)

– Harbors the metacercaria that is Harbors the metacercaria that is infective to maninfective to man


Lung Flukes: Lung Flukes: Paragonimus westermaniParagonimus westermani

Man gets Man gets infected after infected after ingestion of raw ingestion of raw or insufficiently or insufficiently cooked crabs cooked crabs harboring the harboring the metacercariaemetacercariae


Lung Flukes:Lung Flukes:Pathogenesis and Clinical Pathogenesis and Clinical ManifestationsManifestations ParagonimiasisParagonimiasis

– CoughCough– HemoptysisHemoptysis– Symptoms Symptoms

consistent with consistent with pulmonary pulmonary tuberculosistuberculosis

– Misdiagnosed as Misdiagnosed as PTBPTB


Lung Flukes:Lung Flukes:Diagnosis of Diagnosis of ParagonimiasisParagonimiasis Radiographs aid in Radiographs aid in

diagnosisdiagnosis Definitive diagnosis Definitive diagnosis

is based on the is based on the finding of ova in the finding of ova in the sputum, stool or less sputum, stool or less frequently in frequently in aspirated material aspirated material from abscesses or from abscesses or pleural effusionspleural effusions

Multi-dot ELISAMulti-dot ELISAPrepared by FZHapanPrepared by FZHapan

Lung Flukes:Lung Flukes:Treatment of Treatment of ParagonimiasisParagonimiasis PraziquantelPraziquantel

– Drug of choiceDrug of choice– 25 mg/kg body 25 mg/kg body

weight 3x a day weight 3x a day for three dayfor three day

BithionolBithionol– 15 – 25 mg/kg / 15 – 25 mg/kg /

day on alternate day on alternate days for a total of days for a total of 10-15 days10-15 days


Lung Flukes:Lung Flukes:Epidemiology of ParagonimiasisEpidemiology of Paragonimiasis Has a global distributionHas a global distribution In the PhilippinesIn the Philippines

– LeyteLeyte– SorsogonSorsogon– MindoroMindoro– CamarinesCamarines– SamarSamar– DavaoDavao– CotabatoCotabato– BasilanBasilan


Intestinal FlukesIntestinal Flukes


Intestinal Flukes:Intestinal Flukes:Fasciolopsis buskiFasciolopsis buski Giant intestinal fluke of manGiant intestinal fluke of man Parasite of the intestines of humans and Parasite of the intestines of humans and

pigspigs

Mode of transmission is by ingestion of Mode of transmission is by ingestion of encysted metacercariae on aquatic encysted metacercariae on aquatic plantsplants

The viable metacercariae excyst in the The viable metacercariae excyst in the duodenum and becomes mature in duodenum and becomes mature in about three monthsabout three months


Intestinal Flukes:Intestinal Flukes:Fasciolopsis buskiFasciolopsis buski ElongatedElongated OvalOval 20 – 75 mm in length 20 – 75 mm in length

and 8 -20 mm in and 8 -20 mm in widthwidth

Covered with spinesCovered with spines No cephalic coneNo cephalic cone Unbranched intestina Unbranched intestina

caeca which reach up caeca which reach up to the posterior endto the posterior end


Intestinal Flukes:Intestinal Flukes:Life cycle of Life cycle of Fasciolopsis buskiFasciolopsis buski


Intestinal Flukes:Intestinal Flukes:Pathogenesis of Pathogenesis of Fasciolopsis Fasciolopsis buskibuski FasciolopsiasisFasciolopsiasis Pathological changes caused are:Pathological changes caused are: TraumatiTraumati cc

– Inflammation and ulceration Inflammation and ulceration Obstructive Obstructive

– Intestinal obstruction due to heavy infectionIntestinal obstruction due to heavy infection ToxicToxic

– Due to absorption of worm metabolites by Due to absorption of worm metabolites by the hostthe host


Intestinal Flukes:Intestinal Flukes:Diagnosis FasciolopsiasisDiagnosis Fasciolopsiasis Detection of Detection of

parasite eggs in parasite eggs in stoolstool

Resemble Resemble FasciolaFasciola eggs eggs

Provided with an Provided with an operculumoperculum


Intestinal Flukes:Intestinal Flukes:Diagnosis FasciolopsiasisDiagnosis Fasciolopsiasis Detection of Detection of

parasite eggs in parasite eggs in stoolstool– Provided with an Provided with an

operculumoperculum– Large Large – Unembryonated Unembryonated

when laidwhen laid Resemble Resemble

FasciolaFasciola eggs eggs Prepared by FZHapanPrepared by FZHapan

Intestinal Flukes:Intestinal Flukes:Treatment of Treatment of FasciolopsiasisFasciolopsiasis Praziquantel Praziquantel 25 mg/kg for 3 25 mg/kg for 3

doses for one doses for one dayday

Side effects:Side effects:– DizinessDiziness– DrowsinessDrowsiness– Epigastric painEpigastric pain


Intestinal Flukes:Intestinal Flukes:Epidemiology of FasciolopsiasisEpidemiology of Fasciolopsiasis


Intestinal Flukes:Intestinal Flukes:Epidemiology of FasciolopsiasisEpidemiology of Fasciolopsiasis Endemic in Endemic in

– Southeast AsiaSoutheast Asia– ChinaChina– Korea Korea – IndiaIndia

Endemicity in the Philippines has not Endemicity in the Philippines has not been demonstrated yetbeen demonstrated yet

Fasciolopsiasis in Filipinos are probably Fasciolopsiasis in Filipinos are probably imported casesimported cases


Intestinal Flukes:Intestinal Flukes:Echinostoma ilocanumEchinostoma ilocanum

Garrison’s flukeGarrison’s fluke EchinostomidEchinostomid There are several species that infect There are several species that infect

manman There are 2 identified echinostomids There are 2 identified echinostomids

that infect man in the Philippines:that infect man in the Philippines:– Echinostoma ilocanumEchinostoma ilocanum– Artyfechinostomum malayanumArtyfechinostomum malayanum


Intestinal Flukes:Intestinal Flukes:Echinostoma ilocanumEchinostoma ilocanum AdultAdult

– Reddish grayReddish gray– Horse-shape collar of Horse-shape collar of

spines (circum oral spines (circum oral disk) around the oral disk) around the oral suckerssuckers

– 49-51 collar spines49-51 collar spines– Integument is Integument is

covered by plaque covered by plaque like scaleslike scales

– Simple intestinal Simple intestinal caecacaeca


Echinostoma ilocanum showing circum-oral disk


Intestinal Flukes:Intestinal Flukes:Echinostoma ilocanumEchinostoma ilocanum

Echinostoma ilocanum Life cycle


Intestinal Flukes:Intestinal Flukes:Echinostoma ilocanumEchinostoma ilocanum Echinostoma Echinostoma

ilocanumilocanum Ova Ova

– Straw-coloredStraw-colored– OperculatedOperculated– OvoidOvoid– Similar to Similar to FasciolaFasciola

and and Fasciolopsis Fasciolopsis buskibuski ova ova


Intestinal Flukes:Intestinal Flukes:Echinostoma ilocanumEchinostoma ilocanum First Intermediate Host:First Intermediate Host:

– Gyraulus convexciusculusGyraulus convexciusculus

– Hippeutis umbilicalisHippeutis umbilicalis


Intestinal Flukes:Intestinal Flukes:Echinostoma ilocanumEchinostoma ilocanum Second Second

Intermediate Intermediate Host:Host:– Pila luzonicaPila luzonica

(kuhol)(kuhol)

– Vivipara angularisVivipara angularis (susong (susong pampang)pampang)

Pila luzonicaPrepared by FZHapanPrepared by FZHapan

Intestinal Flukes:Intestinal Flukes:Pathogenesis and Clinical Pathogenesis and Clinical Manifestations Manifestations Echinostoma Echinostoma ilocanumilocanum Man gets infected when metacercariae in Man gets infected when metacercariae in

the second intermediate hosts are the second intermediate hosts are ingestedingested

Inflammation at the site of attachment of Inflammation at the site of attachment of adultsadults

UlcerationUlceration Diarrhea (sometimes bloody)Diarrhea (sometimes bloody) Abdominal painsAbdominal pains General intoxicationGeneral intoxication


Intestinal Flukes:Intestinal Flukes:Diagnosis Diagnosis Echinostoma ilocanumEchinostoma ilocanum Detection of Detection of

characteristic characteristic eggs in the stooleggs in the stool


Intestinal FlukesIntestinal FlukesTreatmentTreatmentEchinostoma ilocanumEchinostoma ilocanum PraziquantelPraziquantel

– 25 mg/kg for 3 doses for one day25 mg/kg for 3 doses for one day

– No alcohol; no fats must be taken 24 No alcohol; no fats must be taken 24 hours before and after treatmenthours before and after treatment

– Only water must be taken within 3 Only water must be taken within 3 hours of medicationhours of medication


Intestinal FlukesIntestinal FlukesEpidemiologyEpidemiologyEchinostoma ilocanumEchinostoma ilocanum Echinostoma ilocanum Echinostoma ilocanum is endemic in:is endemic in:

– Northern LuzonNorthern Luzon– LeyteLeyte– SamarSamar– Mindanao provincesMindanao provinces

Artyfechinostomum malayanumArtyfechinostomum malayanum– First reported in 1987First reported in 1987– Northern and Central LuzonNorthern and Central Luzon


Intestinal FlukesIntestinal FlukesHeterophyidsHeterophyids Many species live in the intestine Many species live in the intestine

of fish-eating hosts:of fish-eating hosts:– Heterophys heterophyesHeterophys heterophyes– Metagonimus yokogawaiMetagonimus yokogawai– Haplorchis taichuiHaplorchis taichui– Haplorchis yokogawaiHaplorchis yokogawai


Intestinal FlukesIntestinal FlukesHeterophyidsHeterophyids Mode of transmission is by Mode of transmission is by

ingestion of metacercariae ingestion of metacercariae encysted in fishencysted in fish

Metacercariae in the abdomen Metacercariae in the abdomen excysts, liberating a larva that excysts, liberating a larva that attaches to the intestinal wallattaches to the intestinal wall


Intestinal FlukesIntestinal FlukesHeterophyidsHeterophyids Heterophyes Heterophyes

heterophyesheterophyes Adult Adult– ElongatedElongated– Oval or pyriform Oval or pyriform – Measures less than 2 Measures less than 2

mm in lengthmm in length– Integument has fine Integument has fine

scale-like spinesscale-like spines– Some species have Some species have

gonotyl or genital gonotyl or genital sucker sucker


Intestinal FlukesIntestinal FlukesHeterophyidsHeterophyids Heterophyes Heterophyes

heterophyesheterophyes Ova Ova– Light brown in colorLight brown in color– Ovoid in shapeOvoid in shape– OperculatedOperculated– A fully developed A fully developed

symmetrical symmetrical miracidium is already miracidium is already presentpresent

– Operculum fits into Operculum fits into the egg smoothlythe egg smoothly

– No abopercular No abopercular protuberance like that protuberance like that of of Clonochis sinensisClonochis sinensis ovumovum


Intestinal FlukesIntestinal FlukesHeterophyidsHeterophyids


Intestinal FlukesIntestinal FlukesHeterophyes heterophyesHeterophyes heterophyesPathogenesis and Clinical Pathogenesis and Clinical ManifestationsManifestations HeterophyiasisHeterophyiasis Inflammation at the site of attachmentInflammation at the site of attachment Manifesations are consistent with Manifesations are consistent with

peptic ulcer (observed among infected peptic ulcer (observed among infected individuals in Compostela Valley) individuals in Compostela Valley) – Upper abdominal discomfortUpper abdominal discomfort– Gurgling abdomenGurgling abdomen


Intestinal FlukesIntestinal FlukesDiagnosisDiagnosisPathogenesis and Clinical Pathogenesis and Clinical ManifestationsManifestations Detection of eggs in the stool Detection of eggs in the stool

using Kato Katz methodusing Kato Katz method

Care must be taken to distinguish Care must be taken to distinguish them from them from ClonorchisClonorchis and and Opistorchis Opistorchis ovaova


Intestinal FlukesIntestinal FlukesTreatmentTreatmentPathogenesis and Clinical Pathogenesis and Clinical ManifestationsManifestations PraziquantelPraziquantel

– 25 mg/kg in 3 doses for 1 day25 mg/kg in 3 doses for 1 day


Intestinal FlukesIntestinal FlukesEpidemiologyEpidemiologyPathogenesis and Clinical Pathogenesis and Clinical ManifestationsManifestations Found in Found in

– EgyptEgypt– GreeceGreece– IsraelIsrael– Western IndiaWestern India– Central and South ChinaCentral and South China– JapanJapan– KoreaKorea– TaiwanTaiwan– PhilippinesPhilippines

Compostela ValleyCompostela Valley MindanaoMindanao Emerging public health concernEmerging public health concern


Liver FlukesLiver Flukes


Liver FlukesLiver FlukesFasciola speciesFasciola species Found in the liver and biliary passages of Found in the liver and biliary passages of

humans and ruminantshumans and ruminants

Fasciola hepaticaFasciola hepatica– Sheep liver flukeSheep liver fluke– Temperate liver flukeTemperate liver fluke

Fasciola giganticaFasciola gigantica– Giant liver flukeGiant liver fluke– Tropical liver flukeTropical liver fluke


Liver FlukesLiver FlukesFasciola speciesFasciola species Mode of transmission is by ingestion of Mode of transmission is by ingestion of

metacercariae found in edible aquatic plants or metacercariae found in edible aquatic plants or by drinking water with floating metacercariaeby drinking water with floating metacercariae

Metacercariae excsts in the duodenum or Metacercariae excsts in the duodenum or jejunum and liberate the juvenile flukejejunum and liberate the juvenile fluke

Juvenile fluke penetrates the intestinal wall and Juvenile fluke penetrates the intestinal wall and reaches the liver capsulereaches the liver capsule

The parasite burrows into the liver parenchyma The parasite burrows into the liver parenchyma where it grows and developswhere it grows and develops

It becomes sexually mature in the bile ductsIt becomes sexually mature in the bile ducts


Liver FlukesLiver FlukesFasciola hepaticaFasciola hepatica Adult WormAdult Worm

– Large, broad, flat Large, broad, flat bodybody

– Anterior end Anterior end forms a prominent forms a prominent cephalic conecephalic cone

– Small oral and Small oral and ventral suckersventral suckers

– Long and highly Long and highly branched branched intestinal caecaintestinal caeca


Liver FlukesLiver FlukesFasciola giganticaFasciola gigantica Adult WormAdult Worm

– LargerLarger– More lanceolateMore lanceolate– Less developed Less developed

shoulders shoulders (shorter cephalic (shorter cephalic cone)cone)

– Larger ventral Larger ventral suckersucker


Liver FlukesLiver FlukesFasciola hepatica and giganticaFasciola hepatica and gigantica

Adult WormAdult Worm


Liver FlukesLiver FlukesFasciola hepatica and giganticaFasciola hepatica and gigantica

First Intermediate Host:First Intermediate Host:– Lymnea philippinensisLymnea philippinensis

Second Intermediate HostSecond Intermediate Host– WatercressWatercress– grassgrass


Liver FlukesLiver FlukesFasciola hepaticaFasciola hepatica

Fasciola hepaticaFasciola hepatica OvaOva– LargeLarge– Ovoid Ovoid – OperculatedOperculated– Bile stainedBile stained– unsegmentedunsegmented


Liver FlukesLiver FlukesFasciola hepaticaFasciola hepatica

Fasciola Fasciola giganticagigantica Ova Ova– Larger but very Larger but very

similar to similar to Fasciola Fasciola hepatica hepatica ovaova

*Because of *Because of similarities, it is similarities, it is just safe to say just safe to say FasciolaFasciola ova ova


Liver FlukesLiver FlukesFasciola speciesFasciola species


Liver FlukesLiver FlukesFasciola speciesFasciola speciesPathogenesis and Clinical Pathogenesis and Clinical ManifestationsManifestations FascioliasisFascioliasis AsymptomaticAsymptomatic Can produce feverCan produce fever Right upper quadrant abdominal painRight upper quadrant abdominal pain HypereosinophiliaHypereosinophilia Acute or invasive phaseAcute or invasive phase

– Migration from intestine to liverMigration from intestine to liver– Traumatic and necrotic lesions in liver parenchymaTraumatic and necrotic lesions in liver parenchyma

Chronic or latent phaseChronic or latent phase– AsymptomaticAsymptomatic– Parasite has reached the bile ductsParasite has reached the bile ducts– Obstruction Obstruction – Stimulates inflammation in the biliary epithelium leading Stimulates inflammation in the biliary epithelium leading

to fibrosisto fibrosisPrepared by FZHapanPrepared by FZHapan

Liver FlukesLiver FlukesFasciola speciesFasciola speciesDiagnosisDiagnosis MicroscopyMicroscopy Serologic testsSerologic tests

– Low specificity because of cross Low specificity because of cross reactivity with antigens of other reactivity with antigens of other parasitesparasites

RFLPRFLP– PCR restriction Fragment Length PCR restriction Fragment Length

PolymorphismPolymorphismPrepared by FZHapanPrepared by FZHapan

Liver FlukesLiver FlukesFasciola speciesFasciola speciesTreatmentTreatment BithionolBithionol

– 20-50 mg/kg body weight on alternate days 20-50 mg/kg body weight on alternate days to complete 10 to 5 dosesto complete 10 to 5 doses

TriclabendazoleTriclabendazole– Also a recommended drug of choice due to:Also a recommended drug of choice due to:

EfficacyEfficacy SafetySafety Ease of useEase of use


Liver FlukesLiver FlukesFasciola speciesFasciola speciesEpidemiologyEpidemiology Worldwide distributionWorldwide distribution Economic importance n livestock Economic importance n livestock

raisingraising In the Philippines, the dominant In the Philippines, the dominant

species is species is Fasciola gigantica Fasciola gigantica affecting cattle and water buffalosaffecting cattle and water buffalos

Few human cases are reported Few human cases are reported locallylocally


Liver FlukesLiver FlukesClonorchis sinensisClonorchis sinensis Chinese liver flukeChinese liver fluke Oriental Liver FlukeOriental Liver Fluke Distome of ChinaDistome of China First intermediate Host:First intermediate Host:

– Bulimus fuchsiana Bulimus fuchsiana (snail not found in the (snail not found in the Philippines)Philippines)

Second Intermediate Host:Second Intermediate Host:– Ctenopharyngondon idellus Ctenopharyngondon idellus (fish)(fish)


Liver FlukesLiver FlukesClonorchis sinensisClonorchis sinensis Adult WormAdult Worm

– Narrow, oblong, flat Narrow, oblong, flat wormworm

– Oral sucker is slightly Oral sucker is slightly larger than the ventral larger than the ventral suckersucker

– Blind intestinal caeca Blind intestinal caeca are simple and extend are simple and extend to the caudal regionto the caudal region

– Life span is 20-30 Life span is 20-30 yearsyears


Liver FlukesLiver FlukesClonorchis sinensisClonorchis sinensis OvaOva

– Bile stainedBile stained– Flask-shapedFlask-shaped– OperculatedOperculated– Contains a miracidium Contains a miracidium

when ovipositedwhen oviposited– Does not hatch in Does not hatch in

water but is ingested water but is ingested with a molluscan hostwith a molluscan host

– Has a terminal spineHas a terminal spine– Electric bulb in shapeElectric bulb in shape– Infective to snails onlyInfective to snails only


Liver FlukesLiver FlukesClonorchis sinensisClonorchis sinensisLife CycleLife Cycle


Liver FlukesLiver FlukesClonorchis sinensisClonorchis sinensisPathogenesis and Clinical Pathogenesis and Clinical ManifestationsManifestations ClonorchiasisClonorchiasis Provokes intense proliferation of Provokes intense proliferation of

intestinal epitheliumintestinal epithelium Acute stage (less than 1 month of Acute stage (less than 1 month of

infection)infection)– ChillsChills– FeverFever

Chronic stageChronic stage– CirrhosisCirrhosis– Portal hypertensionPortal hypertension


Liver FlukesLiver FlukesClonorchis sinensisClonorchis sinensisDiagnosisDiagnosis Detection of parasite egg in stoolDetection of parasite egg in stool Clonorchis, Opistorchis and Clonorchis, Opistorchis and

Hetrophyid ova may not be Hetrophyid ova may not be differentiated under ordinary light differentiated under ordinary light microscopemicroscope

ELISA with crude ELISA with crude Clonorchis sinensisClonorchis sinensis antigenantigen

Enzyme immunoassay (EIAEnzyme immunoassay (EIA Polymerase Chain ReactionsPolymerase Chain Reactions


Liver FlukesLiver FlukesClonorchis sinensisClonorchis sinensisTreatmentTreatment PraziquantelPraziquantel

– 25 mg/kg three times a day for two 25 mg/kg three times a day for two daysdays

– 60 mg/kg in three doses for one day60 mg/kg in three doses for one day– May be used together with May be used together with

albendazole for light and moderate albendazole for light and moderate infectionsinfections


Liver FlukesLiver FlukesClonorchis sinensisClonorchis sinensisEpidemiologyEpidemiology Transmission is due to consumption of raw, Transmission is due to consumption of raw,

undercooked fish and salted and dried fish undercooked fish and salted and dried fish harboring the metacercariaeharboring the metacercariae

Over 30 million people are infected in Over 30 million people are infected in Southeastern AsiaSoutheastern Asia

No reported cases in children below 10 years No reported cases in children below 10 years oldold

Endemic in:Endemic in:– ChinaChina– JapanJapan– KoreaKorea– VietnamVietnam


Pancreatic FlukePancreatic Fluke


Pancreatic FlukePancreatic FlukeEurytrema Eurytrema pancreaticumpancreaticum Pancreatic flukePancreatic fluke Stout worm with Stout worm with

ruffled marginsruffled margins oral sucker is oral sucker is

larger than the larger than the ventral suckerventral sucker


Pancreatic FlukePancreatic FlukeEurytrema Eurytrema pancreaticumpancreaticum First Intermediate First Intermediate

Host:Host:– Macrochlamys Macrochlamys

indicaindica (snail) (snail)

Second Second intermediate Host:intermediate Host:– Technomyrmex Technomyrmex

deterquensdeterquens (ant) (ant)


Pancreatic FlukePancreatic FlukeEurytrema Eurytrema pancreaticumpancreaticum OvaOva

– OperculatedOperculated– Thick shelledThick shelled– Dark brown in Dark brown in

colorcolor– Embryonated Embryonated

when laidwhen laid


Trematodes

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