Universal azole prophylaxis for prevention of coccidioidomycosis among lung transplant recipients transferring care to a center within a highly endemic region

Background: Coccidioidomycosis may cause severe disseminated disease and mortality among lung transplant recipients. A strategy of lifelong azole prophylaxis was previously associated with low rates of coccidioidomycosis. Whether lung transplant recipients relocating to the Coccidioides endemic region are also at risk and would benefit from antifungal prophylaxis is unknown. Methods: Lung transplant recipients transplanted at an outside center with low Coccidioides endemicity before relocating for post-transplant follow-up at a transplant center in Phoenix, Arizona from January 2013 to March 2024 were included. The primary outcome was proven or probable coccidioidomycosis per Mycoses Study Group consensus definitions. Results: Forty lung transplant recipients were included, with 62.5% not receiving antifungal prophylaxis at the time of transfer. The median time from transplant to relocation was 34 months. Of those not on prophylaxis, 96% were initiated on azole therapy at the first clinic visit, with 72% prescribed itraconazole. Coccidioides serologic testing was performed in 30% of the cohort, most often in the context of a broad diagnostic work-up for suspected infection during hospitalization. After a median follow-up of 31 months, one case (2.5%) of proven pulmonary coccidioidomycosis was identified, occurring 4.8 years post-transplant and >2 years post-transfer in a cystic fibrosis patient who had a pause in fluconazole prophylaxis for >1 month prior to diagnosis due to gastrointestinal intolerance and access issues. The patient was treated and maintained on isavuconazole without complications. Conclusion: Azole antifungal prophylaxis was associated with a low rate of coccidioidomycosis among lung transplant recipients relocating to the highly endemic region.