Reactivation of coccidioidomycosis despite antifungal prophylaxis in solid organ transplant recipients

Background: Coccidioidomycosis is an airborne infection caused by the fungus Coccidioides, which is endemic to the southwestern United States. Cell-mediated immunity is required for the control of this infection, and some patients such as organ transplant recipients, who lack such immunity, have a high risk of severe, disseminated, or relapsed infection with high mortality. Previously latent coccidioidal infection can reactivate after transplantation. Antifungal prophylaxis has substantially decreased the risk of reactivated coccidioidomycosis after transplantation in these patients. Methods: We conducted a retrospective review of all patients with coccidioidomycosis who underwent solid organ transplantation at our center to identify factors for recrudescent coccidioidomycosis (despite antifungal prophylaxis) after transplantation. Results: Between June 1999 and June 2009, 100 patients with previous coccidioidomycosis underwent solid organ transplantation at our institution. Ninety-four (94%) received anticoccidioidal prophylaxis after transplantation. The six patients who did not receive such prophylaxis did not experience reactivated coccidioidomycosis. Five patients who received anticoccidioidal prophylaxis experienced reactivated infection. All five patients survived with further antifungal treatment. Among patients who experienced recrudescent infection despite antifungal prophylaxis, African American race was an identified risk factor. Pretransplant dissemination may be a risk factor for reactivated coccidioidomycosis, but this finding was not statistically significant. Whether nonadherence to prophylaxis played a small or large role is uncertain. Conclusions: Antifungal prophylaxis effectively suppressed recrudescent coccidioidomycosis after solid organ transplantation for the large majority of patients with a history of coccidioidomycosis before transplantation. Strict lifelong adherence to antifungal prophylaxis is imperative.