CDC Reports Alarming Rise in Cases of Multi-Drug-Resistant Fungal Pathogen
Candida auris Fungal pathogen is commonly resistant to multiple drug classes
One of the biggest challenges in infectious disease management is maintaining a watchful eye on many infectious health threats simultaneously. In the past several years, with nearly all attention on the COVID-19 pandemic, another pathogen continued to spread virtually unchecked: Candida auris.
An Urgent Threat: Candida auris Poses a Growing Public Health Crisis
This fungal pathogen, a type of yeast, has been deemed an urgent threat by the U.S. Centers for Disease Control and Prevention. According to CDC scientists, this designation is intended to sound the alarm on pathogens able to spread easily, cause severe infections, frequently resistant to many classes of drugs, and maintain a high mortality rate. C. auris, in particular—often associated with outbreaks in healthcare facilities—disproportionately affects the most vulnerable within our healthcare systems, such as those who are critically ill in hospitals, are residents of long-term healthcare facilities, or must utilize invasive medical devices.
In a recent publication in the Annals of Internal Medicine, CDC scientists led by Meghan Lyman reported on the growing public health crisis caused by C. auris. Their paper charted the dangerous spread of this fungus in the U.S. from 2019 to 2021.
Challenges in Addressing Candida auris Spread: Underreporting and Drug Resistance
Even with these details in mind, our perception of the full impact of C. auris in this country is woefully incomplete. Clinical cases, which are based on blood or urine samples that test positive for the pathogen, have only been regularly reported to the CDC since 2019. Screening cases, in which a skin swab tests positive from a colonization screening test, are not required to be reported nationally; whether they are sent to CDC or not varies according to local health department policies. Cases where C. auris infection is strongly suspected, but not confirmed by diagnostic testing are not reported at all. In addition to inconsistent reporting practices, some diagnostic tools may lack sensitivity and miss true cases of infection, further depressing the numbers.
C. auris by the Numbers: an Alarming Rise in Multi-Drug-Resistant Cases
Noting that C. auris cases are almost certainly undercounted, the scientists reported a 44% increase in cases in 2019, a 59% increase in 2020, and a 95% increase in 2021. The fungus was first reported in the U.S. in 2016, and in the years immediately following, was detected in 12 states. Between 2019 to 2021, 17 more states reported cases of C. auris for a total of 29 states.
“C. auris has become endemic in some areas, with ongoing transmission within and across healthcare facilities connected via patient transfers,” Lyman and her team reported. “Most [of the] spread in the United States has occurred in high-acuity post–acute care facilities, specifically long-term acute care hospitals (LTACHs) and ventilator-capable skilled-nursing facilities.”
Mitigation Efforts for Candida auris: Infection Control, Diagnostic Testing, and New Antifungal Drugs
Fortunately, the scientists believe that tried-and-true infection control practices can make a real impact. Better and more frequent diagnostic testing such as molecular screening tests, could prove valuable, as can strict isolation and sanitation measures. New tools are needed, though, including “faster and more accessible colonization testing, improved disinfection methods, increased capacity for antifungal susceptibility testing, and new antifungal drugs,” they noted.
In a separate statement issued with the paper, Lyman said, “The rapid rise and geographic spread of cases is concerning and emphasizes the need for continued surveillance, expanded lab capacity, quicker diagnostic tests, and adherence to proven infection prevention and control.”