Aspergillus ustus and Scopulariopsis spp.: two emerging causes of breakthrough invasive mold infections in patients receiving triazoles

Frederic Lamoth

Abstract: 

Background: Invasive mold infections (IMI) are life-threatening complications among patients with hematologic malignancies or solid-organ transplantation. Antifungal prophylaxis with triazoles has been shown to decrease their incidence. We analyzed the epidemiology of IMI breaking throughprophylaxis.

Material/methods: A total of 123 microbiologically documented (proven or probable) IMI wereidentified over a 4-year period (2009-13) at Duke University (Durham, NC, USA). Data on antifungal prophylaxis, susceptibility results, and drug serum concentrations were collected.

Results: Per the table, 24/123 (20%) IMI episodes occurred during voriconazole (16) or posaconazole(8) prophylaxis: 5 aspergillosis, 9 mucormycosis, 3 fusariosis, 4 other IMI and 3 mixed episodes.Rhizopus spp. (6), Fusarium spp. (3), Scopulariopsis spp. (3) and Aspergillus ustus (3) were the most common pathogens. The two latter pathogens were more frequently recovered in breakthrough vs non-breakthrough IMI (21% vs 3%, p=0.007). Overall, 20/24 (83%) breakthrough IMI episodes were due to pathogens with known intrinsic resistance or with an unexpectedly high MIC to the prophylactic drug in use; 1 episode was attributed to inappropriate drug serum level; no explanation was found in 3 cases .

Conclusions: Breakthrough infections represented an important proportion (20%) of this series of microbiologically documented IMI. Intrinsically azole-resistant A. ustus and Scopulariopsisspp. appear as important emerging opportunistic pathogens in this setting accounting for 21% of cases.

2016

abstract No: 

#2480

Full conference title: 

European Congress of Clinical Microbiology and Infectious Diseases
    • ECCMID 26th (2016)