Clonorchis Clonorchis sinensissinensis

by by Albert Teo Albert Teo

& & Doug MandlerDoug Mandler

Taxonomy Taxonomy

KingdomKingdom : : AnimaliaAnimaliaPhylumPhylum : : PlatyhelminthesPlatyhelminthesClassClass : : TrematodaTrematodaOrderOrder : : OpisthorchiidaOpisthorchiidaFamilyFamily : Opisthorchiidae: OpisthorchiidaeGenusGenus : : ClonorchisClonorchisSpeciesSpecies : : C. sinensisC. sinensis

*A quick note – *A quick note – Clonorchis sinensisClonorchis sinensis was given its was given its own genus by Looss because of the parasites own genus by Looss because of the parasites branched testes as apposed to the branched testes as apposed to the OpisthorchisOpisthorchis lobed testes lobed testes

Brief Introduction to Brief Introduction to C. C. sinensissinensis

““Oriental Liver Fluke”Oriental Liver Fluke” Food born parasiteFood born parasite 601 million people are currently at risk, 601 million people are currently at risk,

570 million of which live in China and 570 million of which live in China and Taiwan. Taiwan.

An estimated 30 million people are An estimated 30 million people are infected with infected with C. sinensisC. sinensis..

The parasite may live up to 45 years in The parasite may live up to 45 years in in humans.in humans.

Question!Question!

Why is Why is Clonorchis sinensisClonorchis sinensis known as known as the ‘Chinese/Oriental’ liver fluke?the ‘Chinese/Oriental’ liver fluke?

Because out of the 601 million, 570 Because out of the 601 million, 570 million are Chinese and Taiwanese. It million are Chinese and Taiwanese. It is found predominantly in the regions of is found predominantly in the regions of the world that raw fish is a delicacy.the world that raw fish is a delicacy.

Geographic DistributionGeographic Distribution

Japan Japan KoreaKorea ChinaChina TaiwanTaiwan VietnamVietnam

Definitive HostsDefinitive Hosts Any fish eating mammalsAny fish eating mammals Humans Humans

Humans are an incidental host, the natural Humans are an incidental host, the natural definitive hosts are those that fallow in this listdefinitive hosts are those that fallow in this list

PigsPigs DogsDogs CatsCats RatsRats CamelsCamels

Intermediate HostsIntermediate Hosts

SnailsSnails FishFish First intermediate host must always be First intermediate host must always be

a snail, mainly a snail, mainly Parafossarulus Parafossarulus manchouricusmanchouricus

Second intermediate host is usually a Second intermediate host is usually a fishfish

12 species of fish are mainly responsible 12 species of fish are mainly responsible for passing the infection to humansfor passing the infection to humans

Life CycleLife Cycle

A Closer Look At the Life A Closer Look At the Life CycleCycle

Egg of Egg of C. sinensis C. sinensis that contains miracidium that contains miracidium floats in fresh water until it is ingested by a floats in fresh water until it is ingested by a snailsnail

It will then develop into a sporocyst, which It will then develop into a sporocyst, which houses the asexual reproduction of rediahouses the asexual reproduction of redia

Redia will themselves asexually reproduce Redia will themselves asexually reproduce to form the cercariae to form the cercariae

Cercariae are the free-swimming form of Cercariae are the free-swimming form of the parasites that enables the second the parasites that enables the second intermediate host to be infectedintermediate host to be infected

Critical ThinkingCritical Thinking The asexual reproduction of The asexual reproduction of C. sinensis C. sinensis

enables an exponential multiplication of enables an exponential multiplication of cercaria individuals from one cercaria individuals from one miracidium. How can this aid miracidium. How can this aid C. C. sinensissinensis? ?

-- This aids the Clonorchis in reproduction, This aids the Clonorchis in reproduction, because it enables the miracidium to because it enables the miracidium to captilatize on one chance occasion of captilatize on one chance occasion of passively being eaten by a snail before passively being eaten by a snail before the egg dies. the egg dies.

Life Cycle cont. Life Cycle cont.

The cercariae will then actively bore The cercariae will then actively bore themselves out of the snail themselves out of the snail

It will then It will then seek seek out a fish, and bore out a fish, and bore into the skin/flesh of its targetinto the skin/flesh of its target

Once inside the second intermediate Once inside the second intermediate host, the cercariae will become a host, the cercariae will become a metacercarial cystmetacercarial cyst

QuestionQuestion

Why would the cercariae want to Why would the cercariae want to encyst themselves in the flesh/skin encyst themselves in the flesh/skin of the second intermediate host? of the second intermediate host?

- - The metacercarial cysts are acid-The metacercarial cysts are acid-resistant, thus ensuring that they resistant, thus ensuring that they are protected from the acidic are protected from the acidic environment of the stomach after environment of the stomach after ingestioningestion

Life Cycle cont. Life Cycle cont.

Once in the small intestine, the Once in the small intestine, the metacercariae will excyst metacercariae will excyst

They will then navigate to the liverThey will then navigate to the liver Once at the liver, the Clonorchis will Once at the liver, the Clonorchis will

achieve its sexual maturity stage achieve its sexual maturity stage The hemaphroditic adults produce The hemaphroditic adults produce

eggs every 1 - 30 seconds eggs every 1 - 30 seconds

Picture of C. sinensisPicture of C. sinensis

Pictures cont.Pictures cont.

Sites of InfectionSites of Infection

Infection occurs in the liverInfection occurs in the liver Bile duct is preferred siteBile duct is preferred site The parasite feeds on the bileThe parasite feeds on the bile

Pathogenesis/Clinical Pathogenesis/Clinical SignsSigns

Infection is usually asymptomatic; however, Infection is usually asymptomatic; however, heavy infestation may cause biliary heavy infestation may cause biliary obstructionobstruction

Loss of appetiteLoss of appetite NauseaNausea DiarrheaDiarrhea The sensation of abdominal pressure or painThe sensation of abdominal pressure or pain Rarely, bile duct obstruction may produce Rarely, bile duct obstruction may produce

jaundice followed by cirrhosisjaundice followed by cirrhosis Enlargement and tenderness of the liverEnlargement and tenderness of the liver

Pathogenesis/Clinical Signs Pathogenesis/Clinical Signs ContinuedContinued

Could result in the common bile duct Could result in the common bile duct and/or gall bladder to explode within and/or gall bladder to explode within the human body the human body

May cause adenocarninoma of the May cause adenocarninoma of the bile ducts (cholangiocarcinoma)bile ducts (cholangiocarcinoma)

Loss of fat digestion (severe Loss of fat digestion (severe infestation) infestation)

DiagnosisDiagnosis

Fecal smears and examinations Fecal smears and examinations Duodenal aspirate Duodenal aspirate Adult flukes can also be recovered at Adult flukes can also be recovered at

surgery surgery

TreatmentTreatment

Drugs: Drugs: Praziquantel (most effective) Praziquantel (most effective) AlbendazoleAlbendazole

Control Maneuvers Control Maneuvers

Physical inactivation:Physical inactivation: Sensitive to Sensitive to heating at 56°C for 30 minutes for heating at 56°C for 30 minutes for all infectious stagesall infectious stages

Survival outside host: Survival outside host: Sensitive to Sensitive to freezingfreezing

Susceptible to disinfectants:Susceptible to disinfectants: All All infective stages are susceptible to infective stages are susceptible to 1% sodium hypochlorite 1% sodium hypochlorite

Other Control Measures?Other Control Measures?

What other control measures can be What other control measures can be used to curb the prevalence of this used to curb the prevalence of this parasite? parasite?

- Sanitation Sanitation - Human feces as fertilizer Human feces as fertilizer - Think oral-fecal contamination Think oral-fecal contamination

measures measures

FYI FYI

BE WARNED!BE WARNED!

Metacercariae can remain viable Metacercariae can remain viable even after the fish has been pickled, even after the fish has been pickled, salted, dried, or smoked salted, dried, or smoked

Works CitedWorks Cited http://www.phac-aspc.gc.ca/msds-ftss/http://www.phac-aspc.gc.ca/msds-ftss/

msds34e.htmlmsds34e.html http://animaldiversity.ummz.umich.edu/http://animaldiversity.ummz.umich.edu/

site/accounts/information/site/accounts/information/Clonorchis_sinensis.htmlClonorchis_sinensis.html

http://www.k-state.edu/parasitology/http://www.k-state.edu/parasitology/625tutorials/Clonor02.html625tutorials/Clonor02.html

http://www.k-state.edu/parasitology/http://www.k-state.edu/parasitology/625tutorials/Trematodes08.html625tutorials/Trematodes08.html

http://en.wikipedia.org/wiki/http://en.wikipedia.org/wiki/Clonorchis_sinensisClonorchis_sinensis

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