Clonorchis sinensis by Albert Teo & Doug Mandler

Taxonomy Kingdom: A A A A A nnnn iiii mmmm aaaa llll iiii aaaaPhylum: P P P P P llll aaaa tttt yyyy hhhh eeee llll mmmm iiii nnnn tttt hhhh eeee ssssClass: T T T T T rrrr eeee mmmm aaaa tttt oooo dddd aaaaOrder: O O O O O pppp iiii ssss tttt hhhh oooo rrrr cccc hhhh iiii iiii dddd aaaaFamily: O O O O O pppp iiii ssss tttt hhhh oooo rrrr cccc hhhh iiii iiii dddd aaaa eeeeGenus: Clonorchis Species: C. sinensis *A quick note – Clonorchis sinensis was given its own genus by Looss because of the parasites branched testes as apposed to the Opisthorchis lobed testes

Brief Introduction to C. sinensis “Oriental Liver Fluke” “Oriental Liver Fluke” Food born parasite Food born parasite 601 million people are currently at risk, 570 million of which live in China and Taiwan. 601 million people are currently at risk, 570 million of which live in China and Taiwan. An estimated 30 million people are infected with C. sinensis. An estimated 30 million people are infected with C. sinensis. The parasite may live up to 45 years in in humans. The parasite may live up to 45 years in in humans.

Question! Why is Clonorchis sinensis known as the ‘Chinese/Oriental’ liver fluke? Why is Clonorchis sinensis known as the ‘Chinese/Oriental’ liver fluke? Because out of the 601 million, 570 million are Chinese and Taiwanese. It is found predominantly in the regions of the world that raw fish is a delicacy. Because out of the 601 million, 570 million are Chinese and Taiwanese. It is found predominantly in the regions of the world that raw fish is a delicacy.

Geographic Distribution Japan Japan Korea Korea China China Taiwan Taiwan Vietnam Vietnam

Definitive Hosts Any fish eating mammals Any fish eating mammals Humans Humans Humans are an incidental host, the natural definitive hosts are those that fallow in this list Humans are an incidental host, the natural definitive hosts are those that fallow in this list Pigs Pigs Dogs Dogs Cats Cats Rats Rats Camels Camels

Intermediate Hosts Snails Snails Fish Fish First intermediate host must always be a snail, mainly Parafossarulus manchouricus First intermediate host must always be a snail, mainly Parafossarulus manchouricus Second intermediate host is usually a fish Second intermediate host is usually a fish 12 species of fish are mainly responsible for passing the infection to humans 12 species of fish are mainly responsible for passing the infection to humans

Life Cycle

A Closer Look At the Life Cycle Egg of C. sinensis that contains miracidium floats in fresh water until it is ingested by a snail Egg of C. sinensis that contains miracidium floats in fresh water until it is ingested by a snail It will then develop into a sporocyst, which houses the asexual reproduction of redia It will then develop into a sporocyst, which houses the asexual reproduction of redia Redia will themselves asexually reproduce to form the cercariae Redia will themselves asexually reproduce to form the cercariae Cercariae are the free-swimming form of the parasites that enables the second intermediate host to be infected Cercariae are the free-swimming form of the parasites that enables the second intermediate host to be infected

Critical Thinking The asexual reproduction of C. sinensis enables an exponential multiplication of cercaria individuals from one miracidium. How can this aid C. sinensis? The asexual reproduction of C. sinensis enables an exponential multiplication of cercaria individuals from one miracidium. How can this aid C. sinensis? -This aids the Clonorchis in reproduction, because it enables the miracidium to captilatize on one chance occasion of passively being eaten by a snail before the egg dies.

Life Cycle cont. The cercariae will then actively bore themselves out of the snail It will then seek out a fish, and bore into the skin/flesh of its target Once inside the second intermediate host, the cercariae will become a metacercarial cyst

Question Why would the cercariae want to encyst themselves in the flesh/skin of the second intermediate host? Why would the cercariae want to encyst themselves in the flesh/skin of the second intermediate host? - The metacercarial cysts are acid-resistant, thus ensuring that they are protected from the acidic environment of the stomach after ingestion

Life Cycle cont. Once in the small intestine, the metacercariae will excyst Once in the small intestine, the metacercariae will excyst They will then navigate to the liver They will then navigate to the liver Once at the liver, the Clonorchis will achieve its sexual maturity stage Once at the liver, the Clonorchis will achieve its sexual maturity stage The hemaphroditic adults produce eggs every seconds The hemaphroditic adults produce eggs every seconds

Picture of C. sinensis

Pictures cont.

Sites of Infection Infection occurs in the liver Infection occurs in the liver Bile duct is preferred site Bile duct is preferred site The parasite feeds on the bile The parasite feeds on the bile

Pathogenesis/Clinical Signs Infection is usually asymptomatic; however, heavy infestation may cause biliary obstruction Infection is usually asymptomatic; however, heavy infestation may cause biliary obstruction Loss of appetite Loss of appetite Nausea Nausea Diarrhea Diarrhea The sensation of abdominal pressure or pain The sensation of abdominal pressure or pain Rarely, bile duct obstruction may produce jaundice followed by cirrhosis Rarely, bile duct obstruction may produce jaundice followed by cirrhosis Enlargement and tenderness of the liver Enlargement and tenderness of the liver

Pathogenesis/Clinical Signs Continued Could result in the common bile duct and/or gall bladder to explode within the human body Could result in the common bile duct and/or gall bladder to explode within the human body May cause adenocarninoma of the bile ducts (cholangiocarcinoma) May cause adenocarninoma of the bile ducts (cholangiocarcinoma) Loss of fat digestion (severe infestation) Loss of fat digestion (severe infestation)

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

Treatment Drugs: Drugs: Praziquantel (most effective) Praziquantel (most effective) Albendazole Albendazole

Control Maneuvers Physical inactivation: Sensitive to heating at 56°C for 30 minutes for all infectious stages Physical inactivation: Sensitive to heating at 56°C for 30 minutes for all infectious stages Survival outside host: Sensitive to freezing Survival outside host: Sensitive to freezing Susceptible to disinfectants: All infective stages are susceptible to 1% sodium hypochlorite Susceptible to disinfectants: All infective stages are susceptible to 1% sodium hypochlorite

Other Control Measures? What other control measures can be used to curb the prevalence of this parasite? What other control measures can be used to curb the prevalence of this parasite? - Sanitation - Human feces as fertilizer - Think oral-fecal contamination measures

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

Works Cited /information/Clonorchis_sinensis.html /information/Clonorchis_sinensis.html /information/Clonorchis_sinensis.html /information/Clonorchis_sinensis.html state.edu/parasitology/625tutorials/Clonor02.html state.edu/parasitology/625tutorials/Clonor02.html state.edu/parasitology/625tutorials/Clonor02.html state.edu/parasitology/625tutorials/Clonor02.html state.edu/parasitology/625tutorials/Trematodes08.htm l state.edu/parasitology/625tutorials/Trematodes08.htm l state.edu/parasitology/625tutorials/Trematodes08.htm l state.edu/parasitology/625tutorials/Trematodes08.htm l is is is is Text Book Text Book