In the past several years, there has been much discussion on the influence of indoor environments on the spread of diseases caused by viruses and bacteria. A third category of microorganisms, fungi, originated in the natural environment and has evolved over centuries to coexist with humans along a continuum from mutually beneficial cohabitation to invasive pathogenesis. Whether a particular type of fungus causes human disease is partly determined by environmental forces which guide genetic, reproductive, and biofilm adaptations that increase the fungi’s survival, transmission, and reproduction. Interestingly, adaptations which increase fungal survival in hostile ecological niches may also increase the ability to cause disease in human hosts.
A fungal organism now causing an exponential rise in life-threatening invasive diseases in healthcare facilities worldwide is Candida auris (C.auris), a member of the fairly harmlessly Candida family that is responsible for oral thrush. In 2009, C. auris, was identified in a patient’s infected ear (Latin – auris) canal but was not particularly newsworthy until this year when infections ramped up quickly in health care facilities. In a very short period, C. auris has emerged simultaneously on six different continents and caused outbreaks of infections with mortality rates as high as 60% in hospitals. In March of 2023, the CDC issued a warning that C. auris is an “urgent antimicrobial resistance threat.”