Strongyloidiasis in a Kidney Transplant: Small-Bowel Obstruction and Hyperinfection Treated with Subcutaneous Ivermectin

Introduction: Strongyloides stercoralis can persist asymptomatically for decades but may cause life-threatening hyperinfection in immunocompromised individuals. Solid organ transplant recipients are especially vulnerable, and timely diagnosis is often delayed due to nonspecific symptoms and limited diagnostic accuracy. Case Description: A 66-year-old woman with ESRD underwent deceased donor kidney transplant with thymoglobulin induction and was maintained on tacrolimus, mycophenolate, and prednisone. Five months later, she presented with nausea, vomiting, and melena. CT was initially unremarkable, but repeat imaging showed small bowel obstruction. Laparotomy revealed foreign bodies at the transition point; biopsies from earlier EGD confirmed Strongyloides stercoralis. She was started on oral ivermectin but developed altered mental status, respiratory failure, and bacteremia. Due to ileus and concern for impaired absorption, ivermectin was switched to subcutaneous administration. She gradually improved, with negative stool tests, and was discharged to rehabilitation. Discussion: This case highlights a rare yet fatal manifestation of strongyloidiasis: small bowel obstruction and hyperinfection syndrome in a kidney transplant recipient. Immunosuppression masks typical signs like eosinophilia and allows unchecked parasite replication. Diagnosis is often delayed due to low sensitivity of stool microscopy and limited reliability of serologies in transplant patients. While eosinophilia may suggest parasitic infection, its absence does not exclude strongyloidiasis. Small bowel obstruction is a rare but serious complication of hyperinfection. The patient’s deterioration despite oral ivermectin emphasized the importance of absorption, prompting successful use of subcutaneous ivermectin—an off-label but increasingly recognized intervention. Mortality from disseminated strongyloidiasis exceeds 50%, underscoring the need for heightened clinical suspicion in post-transplant patients with unexplained GI, respiratory, or neurologic symptoms. Preventive strategies are essential: both donors and recipients from endemic areas should be screened and treated pre-transplant when indicated. This case reinforces the importance of early diagnosis, flexible treatment, and institutional protocols to reduce reactivation risk in transplant populations.