Analysis of Candida auris samples from infected US patients highlights the fungal pathogen’s persistence as a multidrug-resistant threat, researchers from the Centers for Disease Control and Prevention (CDC) reported yesterday in Emerging Infectious Diseases.
The analysis of 8,033 C auris clinical isolates by the CDC’s Antimicrobial Resistance (AR) Laboratory Network during 2022 and 2023 found that over 95% were resistant to fluconazole, a first-line antifungal treatment used for a variety of fungal infections, with percentages exceeding 90% in all US regions except the Midwest (83%). Fifteen percent of C auris isolates were resistant to amphotericin B, 1% were resistant to echinocandins, and less than 1% were resistant to all three antifungal classes.
“The frequency of echinocandin resistance (1%) and panresistance (<1%) among C. auris isolates remains low, including among blood isolates, supporting use of echinocandins as first-line therapy against C. auris infections,” the study authors wrote. “However, the number of resistant isolates has increased, and possible spread among patients has been documented.”
C auris cases continue to rise
Since it first appeared in the United States in 2016, the prevalence of the multidrug-resistant yeast has steadily risen, from 51 clinical cases in 2016 to 4,514 in 2023. The number of clinical isolates tested by the AR Laboratory Network, which works with labs across the country to identify and track antimicrobial-resistant pathogens, rose from 3,064 in 2022 to 4,969 in 2023. Invasive infections caused by C auris have been reported in 39 states.
“Our findings highlight the persistence of C. auris as a multidrug-resistant threat requiring sustained investment in laboratory capacity for early detection and response,” the authors wrote.
In addition to its high levels of antifungal resistance, C auris is associated with high mortality rates and spreads easily in health care settings, causing outbreaks. Among the areas that have been hit by C auris outbreaks is Maricopa County, Arizona, where 28 health care facilities reported clinical cases in an outbreak that stretched from April 21, 2022, to February 23, 2023. Description of the local public health response to that outbreak was published today in Infection Control and Hospital Epidemiology.