Chronic diarrhea with blood in stool plus hepatosplenic involvement is characteristic of infection with which parasite?

• A. Schistosoma haematobium
• B. Schistosoma mekongi
• C. Schistosoma japonicum
• D. Schistosoma mansoni and japonicum

Answer: (D)

Chronic intestinal schistosomiasis that also affects the liver and spleen occurs when eggs lodge in the portal system, provoking granulomatous inflammation and periportal fibrosis (Symmers’ pipe-stem fibrosis). This leads to portal hypertension with hepatosplenomegaly and often blood in the stool from intestinal involvement. The species that classically produce this hepatosplenic, intestinal pattern are Schistosoma mansoni and Schistosoma japonicum. In contrast, Schistosoma haematobium affects the urinary tract with hematuria and bladder pathology, not the liver. Schistosoma mekongi can cause intestinal disease as well, but the hallmark hepatosplenic involvement described here points to mansoni or japonicum.