Effect of coccidioidomycosis prophylaxis in selecting non-Candida albicans species amongst solid organ transplant recipients in Arizona

Abstract

Background: Invasive candidiasis carries an increased risk of morbidity and mortality. The rates of non-albicans Candida species (NAC) infections are on the rise secondary to frequent azole antifungal use. NAC incidence and risk amongst solid organ transplant (SOT) recipients in Arizona receiving prolonged azole course for coccidioidomycosis prophylaxis have not been well elucidated. Methods: We retrospectively evaluated SOT recipients hospitalised between 2017 and 2021 with a positive Candida spp. culture. Results: There were 66 SOT recipients with 74 hospitalisations and 79 Candida spp. isolates. The median age was 59 (IQR 45–66), 68% were male, 58% were non-Hispanic White, and the most common SOT 38/74 (51%) was a liver transplant. Median time from transplant to the identification of any NAC (infection or colonisation) was significantly shorter, 8 months (IQR 3–78) vs 128 months (IQR 10–282) for Candida albicans isolates, p =.03. Prior use of azoles was significantly higher in NAC-associated post-transplant colonisation and invasive disease hospitalisations (83%) than in those with C. albicans (17%), p <.001. There were 59 hospitalisations with invasive disease, with the majority having NAC isolates of 49 (83%). Conclusion: The universal azole prophylaxis has reduced the incidence of coccidioidomycosis complications amongst SOT recipients in Arizona; however, there is an increased risk of developing NAC colonisation and infections, which can complicate the care of the SOT recipients with invasive candidiasis. Future studies are needed to investigate methods of reducing the risk of NAC infections whilst preventing coccidioidomycosis amongst SOT recipients.