Parasitic infections in solid organ transplant.

Parasitic infections in solid organ transplant recipients are uncommon but potentially devastating. Transmission may occur through donor-derived infection, reactivation of latent disease, or post-transplant environmental exposure, often with nonspecific presentations that delay diagnosis. Clinically important pathogens include Toxoplasma gondii, Plasmodium spp., Babesia spp., Trypanosoma cruzi, Strongyloides stercoralis, Schistosoma spp., and selected free-living amoebae and intestinal apicomplexans. Diagnosis requires integration of epidemiologic risk, microscopy, serology, molecular testing, and tissue evaluation, each with limitations in immunocompromised hosts. Prevention relies on targeted donor and recipient screening, prophylaxis when indicated, and careful post-transplant surveillance. Because delayed recognition can lead to severe disseminated disease and high mortality, a systematic risk-based approach is essential to improve outcomes in this vulnerable population.