February 19, 2014
2 min read

Transplant microsporidiosis confirmed in three organ recipients

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Three solid organ transplant recipients from a common donor tested positive for the microsporidial species Encephalitozoon cuniculi, according to a report in the Annals of Internal Medicine.

The recipient of the left kidney developed fever, myalgia and fatigue 9 weeks after the transplant. He received treatment for urinary tract infection, neutropenia and organ rejection. Serum testing identified Brucella immunoglobulin M antibodies and a kidney biopsy specimen revealed organisms that were interpreted as brucellae. His illness progressed to anuria, persistent fever and hemodynamic instability and he died 21 weeks after the transplant. The histopathology results by the CDC suggested microsporidiosis. Immunohistochemistry results were negative for Brucella in the allograft specimens, but further tests, including electron microscopy and urine test, confirmed infection with E. cuniculi.

Seven weeks after receiving the bilateral lung transplant, a female recipient developed fever, nausea, vomiting and diarrhea. She received treatment for a UTI and a catheter-associated bloodstream infection, but the fever persisted. Her serum and cerebrospinal fluid showed Brucella antibodies. She received broad-spectrum treatment, but continued to have a low-grade fever and encephalopathy, as well as kidney failure. E. cuniculi were identified in the urine and in a stored colon biopsy. She received 400 mg twice-daily albendazole (Albenza, GlaxoSmithKline), changing to nitazoxanide (Alinia, Romark) after 4 months of therapy because of bone marrow suppression related to albendazole. She was positive for E. cuniculi until month 5 of therapy. She developed post-transplant lymphoproliferative disorder and died 20 months after the transplant.

The right kidney recipient developed fever, fatigue, myalgia, tremors and joint pain 10 weeks after transplant. He received treatment for cytomegalovirus, complicated by ganciclovir-associated thrombocytopenia and leukopenia, UTI and organ rejection. There were no Brucella antibiotics detected. Urine specimens were positive for E. cuniculi. He received 400 mg albendazole twice daily, and improved. His urine was negative for E. cuniculi after 2 months of therapy, and he received 6 months of therapy in total. He remains alive and healthy.

“The search for a cause of this illness cluster, culminating in the diagnosis of microsporidiosis among the organ recipients, was complicated by initial presumption of brucellosis due to positive Brucella test results in two recipients at commercial laboratories,” the researchers wrote. “Microsporidiosis should be considered in the differential diagnosis when an infectious cause is suspected, evaluation for common pathogens is unrevealing and response to standard therapies is poor.”

The investigators said microsporidial infections have primarily been described in those with HIV, but there are increasing reports of it as a donor-derived, transplant-transmitted infection.

Disclosure: The researchers report no relevant financial disclosures.