Mucormycosis coinfection in patients with proven aspergillosis

Data on the coinfection of molds are limited. Therefore, we systematically investigated mucormycosis coinfection in patients with morphologically proven aspergillosis. The medical records of adult patients with proven aspergillosis and available formalin-fixed paraffin-embedded (FFPE) tissue sections were retrospectively reviewed at a tertiary hospital between January 2019 and July 2024. The fungal culture results were reviewed and polymerase chain reaction (PCR) was performed to detect Aspergillus- and Mucorales-specific DNA using FFPE tissues. A positive Mucorales PCR test was confirmed when positive results were obtained for both the 18S and 28S targets. A total of 49 patients with proven aspergillosis were analyzed. The sterile specimen was not found to contain Mucorales. However, fungal cultures from a non-sterile site (endotracheal aspirate) revealed the presence of Aspergillus niger and Cunninghamella spp. in 1 (2%) of 49 patients (Patient A). A positive Mucorales-specific PCR result was obtained for one patient (2%) while positive Aspergillus- and Mucorales-specific PCR results were obtained for five patients, including Patient A (10%). Overall, 6 (12%) of the 49 patients with proven aspergillosis were found to be coinfected with mucormycosis. Coinfection with mucormycosis was significantly more associated with rhino-paranasal sinuses (33% vs. 2%, P = .03). In-hospital mortality was not found to significantly differ between patients with mucormycosis coinfection and those with aspergillosis alone (33% [2/6] vs. 14% [6/43], P = .24). Approximately one-tenth of patients with proven aspergillosis had molecular or microbiologic evidence of mucormycosis coinfection. Further studies are needed to highlight the clinical implications of the molecular evidence of mucormycosis coinfection in patients with proven aspergillosis.