This 30-year-old white male was admitted to the hospital following an upper gastrointestinal hemorrhage with repeated hematemesis. On admission he was tachycardic and had orthostatic hypotension. Endoscopy revealed the presence of esophageal varices. Following fluid replacement and control of bleeding, the patient appeared well. Careful physical exam revealed a palpable spleen extending to the umbilicus. Ascites was not present. The hematocrit was 27%, the white count 12,000 with 30% eosinophils, and the platelet count 98,000. The patient denied alcohol use and had no history of hepatitis. However it was found that two years prior to admission he had worked as a Peace Corps volunteer on a fish-farming project in Ghana. He had been generally healthy while in Africa. He could recall only a fever and cough lasting two or three days, and a brief episode of fever, chills, and headache which was empirically treated as malaria, although no parasites were seen on a single peripheral smear at the time. Since his return to the U.S. eighteen months ago, he had been in good health, but had occasionally noticed some vague left upper quadrant discomfort. Examination of the stool for ova and parasites revealed a few Schistosoma mansoni eggs.
Fresh water snails are required intermediate hosts for schistosomal organisms. The snails release cercaria into the water that can penetrate the skin of anyone walking in the water. Since this patient worked on a fish farm, he spent a lot of time in the water.
A substance released from the eggs is a direct hepatotoxin. The eggs incite a chronic granulomatous inflammatory reaction (thought to be mediated by TNFa and T-helper cells). And schistosome eggs stimulate lymphocytes to secrete lymphokines that stimulate periportal fibrosis.
S. haematobium leads to granulomatous lesions in the urinary bladder that can erode the surface epithelium and lead to hematuria. Chronic inflammation and fibrosis can lead to obstruction, hydronephrosis and ascending bacterial infections. There is also an increased risk for squamous cell carcinoma of the bladder.
- eMedicine Medical Library: Schistosomiasis
- eMedicine Medical Library: Emergent Management of Acute Schistosomiasis
- Merck Manual: Schistosomiasis
- PEIR Digital Library: Schistosomiasis Images
- WebPath: Gastrointestinal Pathology
- WebPath: Hepatic Pathology
Related IPLab Cases
Hematemesis is the vomiting of blood.
Cirrhosis is a liver disease characterized by necrosis, fibrosis, loss of normal liver architecture, and hyperplastic nodules.
Hematuria is the presence of blood in the urine.
Hydronephrosis is dilation of the renal pelvis and atrophy of the cortex due to increase pressure from retained urine.