In 2009, Candida auris , an emerging invasive multidrug-resistant fungus, was isolated from external ear canal discharge of a patient in Japan. Since then, at least a dozen countries, including India, Israel, South Korea, and the United Kingdom, have published reports of C auris infections.
The emergence of C auris raises several serious concerns for public health, according to Morbidity and Mortality Weekly Report : Many isolates are multidrug-resistant; some strains have elevated minimum inhibitory concentrations to drugs in all 3 major classes of antifungal medications—a feature not found in other clinically relevant Candida species. Second, it’s challenging to identify, requiring specialized methods. C auris is often misidentified as other yeasts (most commonly Candida haemulonii ). Finally, C auris has caused outbreaks in health care settings.
In June 2016, the CDC issued a clinical alert asking clinicians, public health authorities, and others to report C auris cases, or suspected cases, to state and local health departments and the CDC. Seven such US cases occurred between May 2013 and August 2016.
All patients had serious underlying medical conditions, including bone marrow transplantation. Four patients, all of whom had bloodstream infections, died during the weeks to months after C auris was identified.
The U.S. isolates were related to isolates from South America and South Asia, although available epidemiologic information suggests that most were acquired in the United States. Several findings suggested that transmission occurred in US health care settings.
Five isolates were resistant to fluconazole; 1 of those was resistant to amphotericin B and another to echinocandins. No isolate was resistant to all 3 classes of antifungal medications.
To reduce the risk of transmission, the CDC advises using Standard and Contact Precautions for patients colonized or infected with C auris . Facilities should ensure thorough daily and terminal cleaning of patients’ rooms with an EPA-registered disinfectant with a fungal claim. In nursing homes, providers should consider the level of patient care being provided and the presence of transmission risk factors when deciding on the level of precautions. When patients are transferred, receiving facilities should be notified of the presence of this multidrug-resistant organism to ensure continuity of precautions.
Five of 7 reported isolates were either misidentified initially as C haemulonii or not identified beyond Candida spp. The CDC urges local and state health departments to continue to report possible cases of C auris and of isolates of C haemulonii and Candida spp. that cannot be identified after routine testing.