Strongyloides infections in transplant recipients

Solid organ transplant recipients can experience serious disease and death from infection due to the parasitic roundworm Strongyloides stercoralis. This parasite lives in soil contaminated with human feces. Domestic dogs and cats may be another reservoir. Larvae can penetrate the skin, are carried hematogenously to the lungs, migrate up the bronchial tree, and then can be passed to the upper small intestine. Autoinfection occurs in the setting of immunosuppression when invasive larvae penetrate the gut wall and cause disseminated infection. Polymicrobial sepsis is sometimes seen due to enteric organisms adhering to the parasite. Transplant recipients are at highest risk during the first 3 months posttransplant. Many organ systems may be affected. Pulmonary symptoms include cough, wheezing, sputum production, dyspnea, hemoptysis, tachypneas, and pleuritic pain. Hyperinfection, an augmentation of the normal skin-lung-intestine life cycle, occurs in roughly two-thirds of infected transplant recipients, with dissemination in the remainder. Diagnosis is made primarily by examination of the stool or intestinal secretions for ova and parasites. Occasionally, parasites are noted in the sputum. New serologic tests show promise. The parasite may remain in the host for over 25 years before immunosuppression causes either dissemination or hyperinfection. Thiabendazole given for 3 to 7 days is the treatment of choice for organ transplant recipients. Repeat courses may be needed to eradicate infection.