Dangerous Drug-Resistant Yeast Infection Rising Across the US, CDC Says

Candida auris, a highly contagious fungal infection that has a high mortality rate, is becoming more resistant to therapy and is rising across the country, according to a new report released Monday.

A study of national surveillance data, conducted by the CDC, found that by multiple measures, the dangerous yeast infection rose drastically between 2019 and 2021. The report, published in Annals of Internal Medicine, examined clinical cases where individuals became sick, colonization screening, and data from the CDC's Antimicrobial Resistance Laboratory Network.

Alarmingly, the CDC said, there has been an increase in cases resistant to a class of antifungal drugs known as echinocandins, a first-line therapy, and evidence of transmission of those cases. The number of C auris cases that were resistant to echinocandins in 2021 was about 3 times that in each of the previous 2 years.

A total of 3270 clinical cases and 7413 screening cases of C auris were reported in the United States through December 31, 2021.

The percentage increase in clinical cases grew each year, from a 44% increase in 2019 to a 95% increase in 2021.

Colonization screening volume rose by more than 80%, and screening cases surged more than 200% in 2021.

C auris was first reported in 2016 in the United States; it is also on the rise in other countries. Hospitalized or institutionalized patients, especially those with mechanical ventilation or a central venous catheter, as well as those who previously received antibiotics or antifungal medications, have the highest risk of infection. Clinical cases of the yeast infection, which is difficult to identify, have been a reportable condition to the CDC since 2019.

However, because screening for the fungus is not conducted uniformly across the United States, C auris cases may be underestimated.

Mortality estimates range; one analysis estimated a mortality rate of 45% for bloodstream infections.

The timing of the spread suggests that it may have accelerated due to the strains of the COVID-19 pandemic, the report said.

"Although infection control gaps existed and caused transmission before the COVID-19 pandemic, the timing of this increased C auris spread and findings from public health investigations suggest it may have been exacerbated by pandemic-related strain on the health care and public health systems, which included staff and equipment shortages, increased patient burden and disease severity, increased antimicrobial use, changes in patient movement patterns, and poor implementation of non–COVID-19 IPC [infection prevention and control] measures," the authors wrote.

Reference

Lyman M, Forsberg K, Sexton J, et al. Worsening spread of Candida auris in the United States, 2019 to 2021. Ann Intern Med. Published online March 21, 2023. doi:10.7326/M22-3469