Clinical utility of fungal screening assays in adults with severe burns

Background: Fungal wound infection is a leading cause of burn wound infections, and diagnosis is often delayed as it conventionally requires culture and histopathology. Fungal screening assays have sped diagnosis of invasive fungal infections in other populations. Few studies have evaluated the performance of fungal screening assays outside of the hematologic malignancy and hematopoietic stem cell transplant populations. Methods: We performed a three year retrospective analysis of all fungal screening assays in burn patients in the ICU between 2008 and 2011. The primary goal was to evaluate the correlation between the two available fungal screening assays, (1 → 3)-β-d-glucan (BG) and galactomannan (GM) assay, and fungal wound colonization (FWC) and infection (FWI). We also evaluated previously hypothesized causes of false positives and their associations with false positives in the burn population. Results: We identified 53 patients [median 29% total body surface area burned (TBSA), IQR 17-51] with BG or GM serological tests available, of which 15 had a FWI or FWC. FWC/FWI was associated with higher TBSA (p = 0.02). BG and GM correlated with TBSA (BG 0.57, p < 0.01; GM 0.35, p = 0.02), but neither assay was associated with FWI/FWC or species of fungus involved when FWI/FWC was diagnosed. Conclusions: Positive BG and GM fungal screening assays are not associated with FWI/FWC, or with species of fungus when FWC/FWI is present. BG false positives are common and associated with higher TBSA burns.