The New England Journal of MedicineChronic Rectal Schistosomiasis

Gastrointestinal Manifestations of Schistosomiasis: A Case Study

Chronic rectal schistosomiasis, a parasitic infection caused by exposure to contaminated freshwater, can lead to significant gastrointestinal complications. This case study highlights the importance of considering schistosomiasis in patients with rectal bleeding, especially those from endemic areas. The article illustrates with images the presentation, diagnosis, and successful treatment of a 29-year-old man with chronic rectal schistosomiasis, emphasizing the role of colonoscopy and biopsy in confirming the diagnosis.

Key Points:

• Patient: 29-year-old man from northeastern Brazil
• Presenting symptom: 2-month history of bright red blood from the rectum
• Notable history: Regular bathing in rivers
• Physical examination: Slight tenderness to palpation of the left flank
• Laboratory finding: Elevated absolute eosinophil count (470 per cubic millimeter)
• Diagnostic procedure: Colonoscopy revealed a reddish, polypoid lesion in the distal rectum
• Biopsy results: Dense inflammatory infiltrate with eosinophils and schistosome eggs
• Diagnosis: Chronic rectal schistosomiasis
• Pathophysiology: Schistosomal eggs in submucosal layers cause inflammatory response and foreign-body reaction
• Resulting complications: Fibrosis, inflammation, and formation of polypoid lesions that can ulcerate and bleed
• Treatment: Praziquantel
• Outcome: Cessation of bleeding episodes after one month
• Follow-up: Colonoscopy at 6 months showed resolution of the polypoid lesion

Estimates show that at least 251.4 million people required preventive treatment for schistosomiasis in 2021, out of which more than 75.3 million people were reported to have been treated. (WHO)

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