Bilharziasis Infection

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Questions and Answers

What is the disease caused by Schistosoma species and what is its status in Egypt?

Chronic specific granulomatous infection, and it is endemic in Egypt.

What is the typical time frame for the peak of a severe febrile illness in acute schistosomiasis?

2 months

What type of immune response dominates in the early stage of acute schistosomiasis?

TH1 response

What cells are stimulated by IFN-γ, leading to the secretion of cytokines?

Macrophages Signup and view all the answers

What is the characteristic skin rash seen in acute allergic dermatitis due to cercaria penetration?

Maculopapular Signup and view all the answers

Where do adult worms typically live in the body?

Inside veins around the bladder (S. hematobium) or colon (S. mansoni) Signup and view all the answers

What is the cause of anemia in chronic schistosomiasis?

Recurrent bleeding due to injury by the spines of ova Signup and view all the answers

What is the characteristic pigment seen in tissues infected with Schistosoma?

Brown bilharzial pigment Signup and view all the answers

What type of granulomas are surrounded by fibroblasts and capillaries?

Fibro-cellular granulomas Signup and view all the answers

What is the result of dead worms being trapped in the venules of the coarse portal tracts?

Thrombophlebitis Signup and view all the answers

What is the function of Kupffer cells in the liver during bilharziasis?

To engulf brown pigment excreted from living worms Signup and view all the answers

What is the characteristic of the liver in bilharzial periportal fibrosis?

Fine granular surface and dark brown cut surface Signup and view all the answers

What is the main site of bilharzial affection in the liver?

Fine portal tracts Signup and view all the answers

What is the result of ova being deposited in the fine portal tracts?

Fibrosis Signup and view all the answers

What is the characteristic of hepatocytes in bilharzial liver disease?

Minimal steatosis Signup and view all the answers

What is the characteristic of the hepatic lobules in bilharzial liver disease?

Preserved architecture Signup and view all the answers

What is the main cause of lesions in the liver according to the text?

Ova and/or dead worms Signup and view all the answers

What is the characteristic feature of the liver's surface in hepatic bilharziasis?

Irregular surface Signup and view all the answers

What type of fibrosis is commonly seen in the portal tracts of the liver in hepatic bilharziasis?

Pipe-stem fibrosis Signup and view all the answers

What is the effect of portal hypertension on the spleen?

Splenomegaly Signup and view all the answers

What is the cause of ammonia encephalopathy in hepatic bilharziasis?

Ammonia escape through open porto-systemic collaterals Signup and view all the answers

What is the common cause of death in hepatic bilharziasis?

Bleeding (hematemesis) Signup and view all the answers

What is the effect of portal hypertension on the liver function?

Mild disturbances of liver functions Signup and view all the answers

What is the cause of ascites in hepatic bilharziasis?

Portal hypertension and lowering of plasma proteins Signup and view all the answers

Study Notes

Bilharziasis (Schistosomiasis)

Chronic, specific, granulomatous infection caused by Schistosoma species, endemic in Egypt
Life cycle and pathogenesis:
- Acute schistosomiasis: severe febrile illness, peak after 2 months
  - Early stage: TH1 cells dominate, producing IFN-γ, stimulating macrophages to secrete cytokines TNF, IL-1, and IL-6, leading to fever
- Chronic schistosomiasis: dominant TH2 response, although TH1 cells persist
  - Parasite egg proteins stimulate mast cells to produce IL-4, leading to TH2 differentiation
  - Both TH1 and TH2 cells contribute to granuloma formation around eggs

Bilharzial Lesions

Lesions produced by Cercaria:
- Acute allergic dermatitis at skin penetration sites
- Gross picture: maculopapular skin rash
- Microscopic picture: dilated capillaries, neutrophils, eosinophils, and macrophages
Lesions produced by adult worms:
- Dead worms: severe inflammation, necrosis, and thrombophlebitis
- Living worms: brown bilharzial pigment in liver, spleen, and other tissues
Lesions produced by ova:
- Recurrent bleeding due to injury by ova spines, leading to anemia
- Trapped ova: sensitization of T lymphocytes, leading to inflammatory response and granuloma formation

Bilharzial Antigens

From worms or ova, causing hyperplasia of lymphoid and reticuloendothelial cells

Liver Bilharziasis

Common in patients with intestinal bilharziasis
Portal tracts show major changes:
- Ova are carried as emboli through the portal vein and trapped in small and large portal tracts
- Granulomas form, leading to fibrosis
Dead worms: trapped in venules, leading to thrombophlebitis
Angiomatoids: dilated capillaries in fibrotic portal tracts, representing dilated collateral channels between branches of the hepatic artery and portal veins
Hepatic lobules: minimal lesions, preserved architecture, and minimal steatosis
Fine bilharzial periportal fibrosis:
- Gross picture: normal-sized liver with finely granular surface and dark brown cut surface
- Microscopic picture: portal tracts show ova, granulomatous inflammation, and fibrosis
Coarse bilharzial periportal fibrosis:
- Gross picture: reduced liver size, firm with irregular surface, and dark brown cut surface
- Microscopic picture: portal tracts show ova, granulomatous inflammation, and fibrosis

Effects and Complications

1. Portal Hypertension:
- Pathogenesis: portal fibrosis leads to compression of portal veins, and angiomatoids convey high pressure of the hepatic artery to the portal veins
- Effects: splenomegaly, ascites, and opening of porto-systemic venous collaterals
1. Portal Vein Thrombosis: may occur due to vascular stasis
1. Mild disturbances of liver functions: lowering of plasma proteins
1. Ascites: due to portal hypertension and lowering of plasma proteins
1. Ammonia Encephalopathy: hepatic portal fibrosis allows ammonia to escape through open porto-systemic collaterals, leading to encephalopathy and coma
Causes of death in hepatic bilharziasis:
1. Bleeding (hematemesis)
2. Superimposed chronic viral hepatitis (relatively common) leading to cirrhosis and liver failure

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Description

This quiz covers the basics of Bilharziasis, a chronic granulomatous infection caused by Schistosoma species, including its life cycle, pathogenesis, and symptoms. It's endemic in Egypt and affects the human body in various ways.