Mycoses

Fungi occur ubiquitously in the environment. They also colonise humans and may cause infections that are referred to as mycoses. While superficial mycoses, e. g. caused by yeasts or dermatophytes, occur rather frequently, an intact immune system usually protects humans from life-threatening systemic mycoses. Most cases of systemic mycosis affect immunocompromised people and are caused by only a few of the approximately 150,000 existing fungi. Depending on the genus, the fungal pathogens can spread to different parts of the human body, i. e. to the bones, joints, skin, stomach and lungs, or to the central nervous system.

Alongside Cryptococcus and Aspergillus, the representatives of the genus Candida are the most common human pathogenic fungi. Of the approximately 150 Candida species, only a handful cause severe systemic infections in immunocompromised people: C. albicans, C. glabrata, C. parapsilosis and C. tropicalis. Since 2009, C. auris has also been spreading worldwide. Many C. auris strains are resistant against commonly used antimycotics, and multiresistant and panresistant strains appear increasingly often. In addition to resistance, the spread of C. auris is further facilitated by its tolerance to disinfectants and heat, as well as its ability to colonise skin and smooth surfaces.

The US Centers for Disease Control and Prevention (CDC) has classified C. auris as an urgent threat and the WHO has categorised it in the highest risk class on its priority list of fungal pathogens.