Stronglyoides Stercoralis Infection from Pancreas Allograft: Case Report

Abstract

Strongyloides stercoralis is endemic to Africa, Eastern Europe, Asia, and Latin America. In the United States, it has a prevalence of 0.4%–4% and is indigenous to the southeast, Appalachian Mountain states, and among immigrants (1). The infective filariform larvae (IFL) live in soil, penetrate the skin or mucosa, and travel hematogenously to the lungs, break into the alveoli, migrate to the pharynx, are swallowed and eventually reside in the bowel. The parasite releases ova within the intestinal mucosa, and hatching noninfective rhabditiform larvae (NIRL) are passed into the feces. NIRL may metamorphose into IFL while still in the intestine, generating autoinfection of the host. In the immunocompetent host, this phenomenon perpetuates the asymptomatic condition for over three decades (2). In patients receiving immunosuppressive agents and steroids, it leads to disseminated infection with a mortality rate over 52% despite treatment (3, 4). Posttransplant strongyloidiasis develops via primary infection, autoinfection, or via the allograft. It has been reported in kidney (4, 5) and heart (3) recipients. However, all the allograft-mediated cases published developed in renal recipients (5). In 1997, Palau (5) has speculated that this mode of transmission is exclusive to kidneys. We report the first case of strongyloidiasis transmitted by a pancreas allograft. Our patient is a 41-year-old man who had never traveled abroad. He underwent a living unrelated kidney transplant 10 years ago for end-stage renal disease complicating type 1 diabetes mellitus. His kidney allograft function is excellent and his maintenance immunosuppression consisted of low dose tacrolimus and prednisone. He received a pancreas allograft from a 33-year-old woman who immigrated to the United States 16 months prior to her death. She became a brain-dead donor due to cerebral hemorrhage complicating severe eclampsia and was treated with high-dose steroids prior to organ donation. She had no eosinophilia. His postoperative course was uneventful. His immunosuppression consisted of antithymocyte globulin, tacrolimus, mycophenolate mofetil, and prednisone. He was discharged on postoperative day 9 in good condition. He was readmitted at 5 and 7 weeks posttransplant for intermittent fever, chills, vomiting, diarrhea, and mild dyspnea. The pancreas allograft function was always normal, and there was no eosinophilia. During the first admission, an infectious workup was negative, and delayed gastric emptying was diagnosed. The symptoms improved with metoclopramide. Two weeks later, an endoscopic biopsy of the duodenum suspecting cytomegalovirus (CMV) infection showed acute and chronic inflammation, with surprisingly cross sections of an adult strongyloides worm and rhabditiform larvae (Fig. 1). There was no evidence of CMV infection.FIGURE 1.: (A) Cross-section of an adult strongyloides worm (thin long arrow points to intestine of worm) in the duodenal mucosa, provoking an intense mixed inflammatory reaction, predominantly neutrophilic (darts). The parasite is located within the superficial epithelium, close to the intestinal lumen (400×; H&E stain). (B) Two small rhabditiform larvae (thin long arrow) of strongyloides, within the duodenal mucosa with lympho- plasmacytic infiltrate in the adjacent lamina propria (dart) (400×; H&E stain).The patient was treated with oral thiabendazole (50 mg/kg/d) and ivermectin (200 μg/kg/d) for 7 days. Recovery was confirmed by serial stool examinations and duodenal biopsy. The donor origin of the infection was documented retrospectively by an enzyme-linked immunosorbent assay detecting Strongyloides stercoralis immunoglobulin G antibody in her serum. Per the United Network for Organ Sharing, the heart, liver, and kidneys recipients are disease-free 20 weeks posttransplant. Ramzi Ben-Youssef, MD Transplantation Institute, Loma Linda University Loma Linda, CA Pedro Baron, MD Transplantation Institute, Loma Linda University Loma Linda, CA Franco Edson, MD Transplantation Institute, Loma Linda University Loma Linda, CA Ravi Raghavan, MD Department of Pathology, Loma Linda University Loma Linda, CA Ojogho Okechukwu, MD Transplantation Institute, Loma Linda University Loma Linda, CA