In endemic areas of the world, which includes most places other than North America and Europe, schistosomiasis is associated with significant morbidity. Think about anemia, diarrhea, chronic pain, fatigue and malnutrition. Specific to the liver, of course, is hepatomegaly, portal hypertension and its sequelae.
The schistosomal eggs lodge themselves in the terminal venules, which is why the classic teaching states that the disease is pre-sinusoidal in nature. However, as you can see from the histologic specimen above, a brisk inflammatory response occurs. Over time, the chronic inflammation leads to fibrosis, and when sufficiently advanced, distorts the lobular architecture and a sinusoidal hypertension occurs. The sequelae are typical, with the formation of ascites, variceal bleeding and encephalopathy. Liver transplantation is curative.
The acutal egg is also seen in the histology above, with the tail sticking out at 4 o’clock. The treatment of active infection is praziquantel, and its side effects are usually mild in nature.