Donor‐Derived Strongyloides Infection Leading to Hyperinfection Syndrome in a Heart Transplant Recipient

Donor‐derived Strongyloides stercoralis infection is an uncommon but potentially fatal complication of solid organ transplantation. We describe a case of progression to hyperinfection syndrome with dissemination in a 60‐year‐old woman following orthotopic heart transplantation. Pretransplant serologic screening for Strongyloides was negative, and the patient had no significant epidemiologic risk factors aside from remote travel to Mexico more than two decades earlier. Two months after transplant, she developed progressive gastrointestinal symptoms, eosinophilia, and rash. Duodenal biopsy confirmed Strongyloides infection. Despite prompt initiation of oral ivermectin, her clinical course progressed with diffuse alveolar hemorrhage (DAH) and purpuric skin lesions. Bronchoalveolar lavage (BAL) and skin biopsy demonstrated filariform larvae. Severe ileus prompted the emergency use of subcutaneous ivermectin under an FDA Investigational New Drug (IND) application. The cutaneous eruption improved rapidly, and the clearance of parasites from stool exam was achieved after prolonged therapy. The patient completed a 40‐day course of ivermectin with clinical recovery. This case highlights the potential for donor‐derived Strongyloides transmission even in nonendemic regions and illustrates the role of subcutaneous ivermectin in select clinical cases. It also highlights how recently implemented universal donor screening policies may prevent similar adverse outcomes. We report a case of donor‐derived S. stercoralis infection resulting in progression to hyperinfection syndrome with dissemination following orthotopic heart transplantation. A 62‐year‐old woman with end‐stage nonischemic cardiomyopathy and a remote history of Hodgkin’s lymphoma treated with radiation and ABVD chemotherapy underwent orthotopic heart transplantation in 2024. Pretransplant serologic screening, including Strongyloides IgG, was negative. Travel history was limited to a brief trip to Mexico over 20 years prior. Immunosuppression included tacrolimus, mycophenolate mofetil, and prednisone, with valganciclovir and trimethoprim–sulfamethoxazole prophylaxis. Two months after transplantation, she developed progressive nausea, vomiting, abdominal pain, and odynophagia. Laboratory evaluation revealed leukopenia (3.7 × 10 3 / μ L ) with marked eosinophilia (43%). Stool pathogen testing, blood cultures, and cytomegalovirus (CMV) and Epstein–Barr virus (EBV) DNA levels were negative. Upper endoscopy demonstrated erosive gastropathy, and duodenal biopsy revealed Strongyloides organisms. Oral ivermectin was initiated. Given the negative pretransplant serology, donor‐derived transmission was suspected and promptly reported to the Organ Procurement Organization (OPO). Investigation revealed another recipient from the same donor—originally from Central America—had also developed Strongyloides infection, confirming donor transmission. Despite treatment, the patient’s condition deteriorated. She developed fever, diffuse abdominal tenderness, and a maculopapular rash that evolved into purpura. Blood cultures grew ESBL Enterobacter cloacae , treated with meropenem. On hospital Day 7, she required ICU admission for hypoxic respiratory failure. Computed tomography (CT) showed diffuse pulmonary opacities, and BAL revealed DAH with numerous Strongyloides larvae, consistent with hyperinfection syndrome. Severe ileus developed with progressive abdominal distension and inability to tolerate enteral intake, raising concern for impaired enteral absorption of ivermectin. Triggers prompting escalation to parenteral therapy included worsening ileus with placement of nasogastric tube (NGT) for decompression and initiation of continuous suction. The patient also remained critically ill after several days of oral therapy, with serious complications from infection including acute respiratory distress syndrome (ARDS), gram‐negative bacteremia, and septic shock requiring vasopressor support. An emergency single‐patient IND request was submitted to the FDA, coordinated through the hospital investigational pharmacy. Approval was obtained within 24 h after submission of clinical justification, dosing and monitoring plan, and informed consent documentation. The single‐patient IND application for subcutaneous ivermectin required a prespecified dosing and monitoring plan with clear treatment endpoints: subcutaneous ivermectin was administered while enteral absorption was unreliable, with stool ova and parasite examinations obtained every 3 days to assess parasitic clearance, and transition back to oral ivermectin once the patient was tolerating enteral nutrition and gastrointestinal absorption was expected to be adequate. Veterinary‐grade subcutaneous ivermectin (200 μ g/kg every 48 h) was procured and compounded by the inpatient compounding pharmacy. Following parenteral therapy, the purpuric lesions—most prominent in the periumbilical region, flanks, and proximal thighs—began fading within 48 h. Skin biopsy confirmed filariform larvae within dermal collagen bundles, consistent with disseminated strongyloidiasis and periumbilical parasitic thumbprint purpura. The hospital course was complicated by vancomycin‐resistant Enterococcus faecium meningitis, treated with linezolid. Serial stool ova and parasite examinations became initially negative after 13 days of subcutaneous ivermectin. Therapy continued for a total of 40 days until multiple consecutive stool O&P samples were negative, confirming parasite clearance. Treatment was successful and she was ultimately discharged on hospital Day 63.