Schistosomiasis/Fascioliasis

Question 1

What is schistosomiasis?

Answer 1

From host’s immune response to schistome eggs

Flukes = flatworm

The parasite enters through skin –> lymph –> veins

1st intermediate host is a snail

Question 2

What is acute schistosomiasis?

Answer 2

Larvae penetrate skin which leads to egg deposition –> immune response to migrating larvae

Causes Katayama Fever: fever, cough, headache, muscular pain, GI complaints, pulmonary symptoms (cough, wheeze)

Swimmer’s itch at site of penetration, can cause schistosomes dermatitis

Eosinophilia

Question 3

What can cause chronic schistosomiasis?

Answer 3

Schistosoma mansoni or japonicum –> liver/GI symptoms (portal htn, varices, pipe-stem fibrosis in liver, eggs in liver)

OR

Schistosoma haematobium –> GU symptoms (terminal hematuria, dysurea, renal sequelae, squamous cell carcinoma of bladder)

Both due to worms in portal system laying eggs in veins of intestine (1st option) or bladder (2nd option)

Question 4

How do you diagnose schistosomiasis?

Answer 4

Diagnose wtih stool or urine ova&parasites, Fast-ELISA (serology, which doesn’t distinguish past/current)

Question 5

How do you treat it?

Answer 5

Treat with Praziquantel (retreat, only works in adult worms) which opens gated ion channels & paralyzes parasite

Question 6

What is fasciola?

Answer 6

You eat the larva from watercress sandwiches –> enters through intestinal wall –> through Glisson’s capsule –> through inner parenchyma –> bile duct

Fasciola hepatica lives in hepatic bile duct

Acute infection = anorexia, RUQ pain, eosinophilia (during mirgating through liver stage)

Causes bile stones in chronic infections

Diagnose with Stool O&P, serology

Treat with Triclabendazole, which binds tubulin