Clonorchis sinensis is a liver fluke parasite that infects humans when they ingest raw or undercooked freshwater fish containing the parasite's larval stage. The parasite matures in the bile ducts of the liver and gallbladder, causing inflammation, thickening of duct walls, and obstruction. Heavy infections can lead to cholecystitis, cholangitis, and long-term complications like liver cirrhosis. Most light infections are asymptomatic, but heavy acute infections may cause fever, jaundice, hepatomegaly, and eosinophilia. Diagnosis is made by finding the parasite's eggs in stool samples or duodenal fluid.

1. Clonorchis sinensis
Prepared by:
 Shafqat Hussain
 Jamal Nasir
 Obaidullah

2. Objective:
• Taxonomy
• Introduction
• Morphology
• Host
• Life cycle
• Pathogenesis
• Clinical manifestation
• Laboratory findings

3. Taxonomy
• Kingdome : Animalia
• Phylum : Platyhelminths
• Class : Trematoda
• Order : Opisthorchiida
• Family : Opisthorchiidae
• Genus : Clonorchis
• Species : C. sinensis

4. Introduction
• Clonorchis is also known as the Chinese or oriental liver fluke.
• Clonorchis is a liver fluke parasite (trematode or worm) that can
infect the liver, gallbladder, and bile duct.
• food born parasite

5. Adult worm morphology
• Flat, elongated worm.
• size 10-15×3-5 mm
• They are monocious, with two
suckers
• The most characteristic
feature is branched testis in
the posterior third of the body,
and relative small ovary before
them

6. Morphology (eggs)
• Small, 26-30 x 15-17 um
• Ovoid, yellowish color
• Operculated at one end,
small knob at opposite
end

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

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

9. • Source of infection: patients, infected reservoir hosts:cats, dogs,
mice, pigs
• Route of transmission: the infection is acquired by eating raw or
inadequately cooked freshwater fish or shrimp, which are
previously infected
• Susceptibility: human is generally susceptive, related with the
dietary habits

10. Life cycle

11. Life cycle
• Clonorchis sinensis eggs are discharged in the biliary ducts and in
the stool in an embryonated state
• Eggs are ingested by a suitable snail (P. manchouricus)
intermediate host
• Eggs release miracidia
– which go through several developmental stages (sporocysts, rediae, and
cercariae).
• The cercariae are released from the snail and, after a short period
of free-swimming time in water, they come in contact and
penetrate the flesh of freshwater fish, where they encyst as
metacercariae

12. Life cycle
• Infection of humans occurs by ingestion of under cooked, salted,
pickled, or smoked freshwater fish
• After ingestion, the metacercariae excyst in the duodenum
• and ascend the biliary tract through the ampulla of Vater
• Maturation takes approximately one month. The adult flukes
(measuring 10 to 25 mm by 3 to 5 mm) reside in small and
medium sized biliary ducts.
• they lay eggs in intestine
• the embryonated eggs release in stool.

13. • The eggs are embryonated and contain the larvae called
miracidia.
• The sporocyst resembles a hollow and simple sac.
• Oftentimes, the developing rediae are visible inside the sac.
• Redia - At this larval stage, it retains a very simple worm
structure.
• In some ways, it still resembles a sac.

14. Pathogenesis
• Liver flukes infect the liver, gallbladder, and bile duct in humans.
• inflammation in biliary epithelium
• The wall of the bile ducts thickened ,fibrous tissue around the bile
duct, and worm obstruction cause cholestasis
• secondary infection like bacterial infection occur, cause
cholecystitis, cholangeitis, sometimes cholelithiasis happens
• Intrahepatic bile ducts expansion, hepatomegaly, necrosis of liver
tissue
• Continuous severe infection may cause liver cirrhosis, Persistent
Cholestasis cause biliary liver cirrhosis
• Pancreatitis

16. Clinical Manifestation
• Incubation period: 1-2 months
• Most person with mild clonorchis sinensis infections are asymptomatic, only
eggs can be found in the feces
• Acute symptoms appear when the primary infection is heavy: sudden onset,
chill, high fever, slight jaundice, hepatomegaly, eosinophilia, a few patients
have splenomegaly, and weeks later, enter chronic stage
• Continuous reinfection: cirrhosis and portal hypertension. In children may
cause malnutrition growth development disturbance, even dwarf

17. Laboratory Findings
• Blood routine test: eosinophilia, anemia in severe infection
• Eggs examination: simple smear feces to find eggs
– Stool concentration technique may increase the positive rate
– Duodenal aspiration: raise the chance of finding eggs
• Immunological Test
– Skin test: positive rate 97.9%, 99.5% coincide with the result of the feces
– PHA: positive rate 53.7%, 80% coincide with the result of the feces
– ELISA: positive rate 98.3%, 93.5% coincide with the result of the feces