Donor-Derived Strongyloides stercoralis Infections in Renal Transplant Recipients

Background. Donor-derived Strongyloides stercoralis infection occurs rarely after transplantation, and the risk factors are not well understood. We present cases of two renal allograft recipients who developed Strongyloides hyperinfection syndrome after receipt of organs from a common deceased donor who received high-dose steroids as part of a preconditioning regimen. Methods. The two renal transplant patients who developed Strongyloides hyperinfection syndrome are reported in case study format with review of the literature. Results. Microscopic examination of stool from one renal transplant patient and of tracheal and gastric aspirates from the other transplant patient revealed evidence of S. stercoralis larvae. Retrospective testing of serum from the deceased donor for Strongyloides antibodies by enzyme-linked immunosorbent assay was positive at 11.7 U/mL (Centers for Disease Control reference >1.7 U/mL positive). One patient was treated successfully with oral ivermectin. The other patient also had complete resolution of strongyloidiasis, but required a course of parenteral ivermectin because of malabsorption from severe gastrointestinal strongyloidiasis. Conclusions. These case studies provide some of the best evidence of transmission of S. stercoralis by renal transplantation. Because of the high risk of hyperinfection syndrome and its associated morbidity and mortality, high-risk donors and recipients should be screened for Strongyloides infection, so that appropriate treatment can be initiated before the development of disease. This study indicates that parenteral ivermectin can be used safely and effectively in patients in whom severe malabsorption would preclude the effective use of oral formulation. These cases also suggest that reconsideration should be given for the safety of steroids in donor-preconditioning regimens.