Trematodes(flukes)

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TREMATODES (FLUKES)



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Hermaphroditic (both male and female reproductive organs in single body) Exception- schistosomes 1st intermediate host-mollusks (snails and clams) Eggs have operculum-allows larval worm to find the host (exception-schistosomes)

Types        

Fasciolopsis buski Fasciola hepatica Opisthorchis sinensis Paragonimus westermani Schistosomes S.mansoni S.japonicum S.haematobium

FASCIOLA BUSKI  

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Giant intestinal fluke Largest, most prevalent fluke Intermediate host-snail Reservoir hostpigs,dogs,rabbits,humans Biologic vector-water plants

Life cycle

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Infective stage- metacercaria Diagnostic stage- eggs in feces Free swimming larval stage-miracidium

Clinical features   

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Abdominal discomfort,diarrhoea Marked eosinophilia Worm takes up residents in the bile ducts,ther mechanical irritation and toxic secretions cause hepatitis,biliary obstruction etc Lab diagnosis Stool microscopy-large, golden,bile stained eggs with an operculum on the top DOC-praziquantel Proper sanitation measures

FASCIOLA HEPATICA   



Sheep liver fluke Intermediate host-snail Biological vector-water plants Reservoir host-sheep, cattle, humans

Life cycle



Lab diagnosis and treatement same as that of buski

OPISTHORCHIS SINENSIS 

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Also called clonorchis sinensis/CHINEESE LIVER FLUKE Intermediate host-snail and fresh water fish Biologic vector-uncooked fish Reservoir host-dogs,cats, humans

Life cycle

Clinical features 



Pain in the right upper quadrant over the liver,chills,fever, marked eosinophilia. Hepatitis ,portal cirrhosis, invades the bile duct

Lab diagnosis & treatment  





Stool examination- unembryonated eggs Eggs are present in the bile also, unlike f.buski which is limited to small intestine Bithionol or benzimadazole compound triclabendazole are the drugs used Avoid uncooked acquatic vegetation

PARAGONIMUS WESTERMANI  

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Lung fluke Intermediate host-snail, fresh water crabs, Cray fish Biologic vectors-uncooked crabs, Cray fish Reservoir host-pigs, monkeys and humans

Life cycle



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Infective stage-metacercariae in the fresh water crabs Larva hatches in the stomach and migrate Adult worm resides in the lungs Eggs from it released in sputum or feces

Clinical features 



Onset coincides with larval migration-fever, chills and high eosinophilia When it reaches the lung-fever. cough and increased sputum-blood stained and dark with eggs(RUSTY sputum),chest pain

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c/c infections lead to fibrosis of lung May invade brain and spinal cord-cerebral paragonimiasis Also invades subcutaneous tissue, abdominal cavity and liver

Lab diagnosis 

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Examination of sputum and feces-golden brown operculated eggs Chest xray-pleural effusions,cyst,infiltrates Eosinophilia

Treatment  



DOC-praziquantel Avoid consumption of uncooked fresh water crabs Proper sanitation

SCHISTOSOMES(blood flukes)       

S.MANSONI S.JAPONICUM S.HAEMATOBIUM Causes-schistosomiasis/bilhariasis/snail fever Separate male and female flukes Intermediate host-snail Reservoir host-rodents, domestic pets, live stock, humans

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Eggs do not have operculum. Infective stage- cercariae S.mansoni and japonicum- mesenteric veins and produce intestinal amoebiasis S.hematobium – veins around the urinary bladder and causes vesicular schistosmiasis.

Life cycle

Clinical features 





Earliest symptoms- penetration of cercaria though the skin- pruritic rash Onset of oviposition-katayama syndromefever,chills,cough,urticaria,arthralgia,lymphad enopathy,splenomegaly,abdominal pain cases- granulomas and fibrosis

S.MANSONI  o 

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EGGSOval and have a sharp lateral spine. Dermatitis with allergic reaction,pruritis,edema In lungs-cough Liver-hepatitis





Intestinal-abdominal pain,diarrhoea,tenderness of liver c/c cases-hepatosplenomegaly with large accumulations of ascitic fluid in pleural cavity





Gross examination-liver-pseudotubercles (white granulomas) Clay pipe stem fibrosis- fibrous tissue reacting to the eggs in liver surrounds the portal vein in a thick and grossly visible layer

Lab diagnosis   



Demonstration of eggs DOC-praziquantel Schistosomal dermatitis and katayama syndrome –treated with administration of antihistamines and steroids Improved sanitation

S.JAPONICUM   



EGGS- spherical, tiny spine Clinical features same as mansoni Frequently involves the CNSgranulomas,lethargy,speech impairment, visual defects, seizures DOC-praziquantel

S.HAEMATOBIUM  

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Mainly in the Nile valley Develops in the liver and migrates to vesical,prostatic,uterine plexus of venous circulation Eggs-sharp with a terminal spine Eggs may be seen in urine Reservoir hosts-monkeys,baboons,chimpanzees

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Initial features are similar to others But also has hematuria,dysuria,urinary frequency Develops obstructive uropathy in the end stage May show squamous cell carcinoma of bladder DOC- praziquantel

Cercarial dermatitis 

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Swimmers itch-non human cercaria produce dermatitis, but they cannot develop in the human host Can lead to secondary bacterial infection Treatment-oral trimeperazine, topical antihistamines