Current Epidemiology and Infection Characteristics of Non- Aspergillus Mold Infections: A Multicenter Study in Australia and New Zealand

Abstract Background Understanding the epidemiology of invasive non-Aspergillus mold infections is essential to inform effective therapy. Robust regional studies remain scarce. This study aimed to determine the epidemiology and infection characteristics of non-Aspergillus mold infections in Australasia. Methods A 21-center, retrospective study of proven/probable non-Aspergillus mold infections from 2016 to 2023 was conducted in Australia and New Zealand. Data collected included demographic, clinical, microbiological, treatment and outcome information until 180 days of follow-up. Results Of 421 cases, 346 (82.2%) were proven infections and 315 (74.8%) were localized. Lung (n=150/421, 35.6%) was the most common site of infection. Twenty cases (4.8%) were due to 1 non-Aspergillus mold pathogen, resulting in 443 isolates altogether. Dematiaceous molds, inclusive of Lomentospora prolificans (n=96, 21.7%), Scedosporium spp. (n=87, 19.6%) and other dematiaceous molds of various genera (n=48, 10.8%), were the most common (n=231, 52.1%), followed by Mucorales (n=141, 31.8%). Common underlying conditions were hematological malignancy (n=146/421, 34.7%) and diabetes mellitus (n=122/421, 29.0%) while 68 cases (16.2%) had no comorbidities. Lymphopenia was present in 46.6% (n=196/421). One-third (n=138/421, 32.8%) received antifungal prophylaxis 30 days before non-Aspergillus mold diagnosis and L. prolificans was the most common cause of breakthrough infections (p0.001). All-cause 90-day mortality was 31.4% (n=132/421), with higher mortality observed in L. prolificans (n=51/89, 57.3%) and Mucorales (n=56/129, 43.4%) infections. Conclusions L. prolificans, Scedosporium spp. and Mucorales are the most frequent non-Aspergillus mold pathogens in Australasia, with other emerging species and mixed infections encountered. Mortality from L. prolificans and Mucorales infections remains high.