Emerging Fungal Infections: New Species, New Names, and Antifungal Resistance

Background: Infections caused by fungi can be important causes of morbidity and mortality in certain patient populations, including those who are highly immunocompromised or critically ill. Invasive mycoses can be caused by well-known species, as well as emerging pathogens, including those that are resistant to clinically available antifungals.

Content: This review highlights emerging fungal infections, including newly described species, such as Candida auris, and those that having undergone taxonomic classification and were previously known by other names, including Blastomyces and Emergomyces species, members of the Rasamsonia argillacea species complex, Sporothrix brasiliensis, and Trichophyton indotinae. Antifungal resistance also is highlighted in several of these emerging species, as well as in the well-known opportunistic pathogen Aspergillus fumigatus. Finally, the increased recognition and importance of fungal co-infections with respiratory pathogens, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is discussed.

Summary: Both clinicians and clinical microbiology laboratories should remain vigilant regarding emerging fungal infections. These may be difficult both to diagnose and treat due to the lack of experience of clinicians and laboratory personnel with these organisms and the infections they may cause. Many of these fungal infections have been associated with poor clinical outcomes, either due to inappropriate therapy or the development of antifungal resistance.