(546) Progression of Fungal Wound Colonization to Infection After Burn Injury: A 15-Year Review

Introduction: Fungal wound infection (FWI), but not fungal wound colonization (FWC), was previously identified as an independent predictor of mortality risk in burn patients. In this study, we examined whether patients with FWC may progress to FWI, and whether this is associated with increased risk of death.

Methods: Patients with clinically suspected FWC or FWI routinely undergo full-thickness incisional biopsies, followed by histopathological examination and microbiological speciation. FWC is defined histopathologically as the presence of fungal elements in non-viable tissue only, and FWI as the presence of fungal elements in viable tissue or angioinvasion. Patients admitted between 2004-2019, and initiated on a systemic antifungal were identified. Patients were included if antifungals were initiated out of concern for FWI but whose initial diagnosis on histopathology was that of FWC. These patients were followed to determine whether FWI was later diagnosed.

Results: 117 patients had FWC. Of these, 79.5% did not develop FWI (Group A), and 24 (20.5%) did (Group B). Demographic data did not significantly differ between Groups A and B. Total burn size was similar (Group A, 46.2±16.7%; Group B, 52.9±21.9%; p=0.12). Age was similar (Group A, 47±19.9 years; Group B, 40.3±18.5 years; p=0.14). Group A had a longer delay between day of burn and diagnosis of FWC (Group A, 23.2±21.2 days; Group B, 17.8±12.2 days; p=0.105). The average time from FWC to FWI was 13.9±18.5 days.
For patients who had positive fungal wound cultures, Aspergillus was the most commonly isolated genus (55.17% in Group A vs 62.5% in Group B), followed by Candida (37.9% vs 50%), Fusarium (10.3% vs 25%), and Mucor (6.9% vs 12.5%). Group A had a longer hospital LOS than Group B (90.8±73.7 days vs 61.9±44.3 days; p=0.018). This is likely due to the higher mortality in Group B (45.2% vs 75%; p=0.009).

Conclusions: Over 20% of patients who presented with FWC went on to develop FWI, and such progression was associated with a significant increase in mortality. Thus, patients with FWC should be frequently reassessed; topical antimicrobial therapy should be changed to include coverage for molds, including Aspergillus, Fusarium, and Mucorales; and aggressive surgical intervention should be performed as indicated.