endemic(native) areas are in asia including korea, china, taiwan, and vietnam. there have been cases...
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Geographic distributionEndemic(native) areas are in Asia including Korea, China, Taiwan, and Vietnam. There have been cases in the United States in Asian immigrants due to the ingestion of undercooked freshwater fish containing metacercariae(infective cyst stage).
Hosts
Definitive host: humans, fish eating vertebrates
1st Intermediate host: some sort of snail
2nd Intermediate host: freshwater fish(over 100 species), common one is the grass carp
Morphology Adults 8-25 mm long and 1.5 to 5
mm wide
Weak muscularity, lack spines
Have oral sucker at anterior end
Epidemiology
A problem in Asia where raw fish is a delicacy
Many fish farms where fish are fed with human and animal feces, thus promoting the C. sinensis lifecycle
Metacercarie will survive pickling, drying, smoking, and salting so people can be infected where this imported fish is consumed
Dogs and cats also contaminate water supplies with feces
Pathology
Causes clonorchisasis C. sinensis generally only inhabit 2nd
order bile ducts, 1st order to small Cause production of excess mucus,
erosion of epithelial lining, and surplus epithelial cell growth
Duct inflammation and necrosis or atrophy of adjacent liver cells
Deformation of ducts leads to gradual thickening and possible closure of duct
Infiltrating pockets of eggs become surrounded by granulomas and interfere with liver function
Advanced clonorchiasis can cause cancer of the bile duct
Diagnosis and Treatment
Diagnosis is based on the look of eggs recovered from feces.
Liver abnormalities in native areas or populations are a good clue for clonorchiasis, must be careful to rule out other liver diseases
Tissue sample to look for adult flukes is also used
Treatment Drug used is called Praziquantel which kills the
flukes in the intestine Side effects include: headaches, dizziness,
drowsiness, fever, nausea, stomach pain