Isospora belli infection after isolated intestinal transplant.

Isospora belli is a protozoan that only affects humans, after ingestion of Isospora's oocysts. Immunocompetent patients usually do not develop the infection. Immunocompromised hosts may have profuse diarrhea with other gastrointestinal symptoms. Treatment is based on trimethoprim-sulfamethoxazole. In 2006 we performed an isolated intestinal transplantation in a patient with ultra-short bowel syndrome. Neither rejection nor clinical problems occurred after transplant, but signs of intestinal inflammation were seen in every protocol biopsy starting at the first month post transplant. Almost 3 months after the procedure, the patient was re-admitted with diarrhea. I. belli infection was diagnosed by detection of the oocysts in stool samples. Antibiotic treatment with trimethoprim-sulfamethoxazole was initiated with excellent outcome and without relapses. To the best of our knowledge, this is the first case of isosporosis in a small bowel recipient.