C. auris cases, echinocandin resistance, increasing in US

Key takeaways:

• Cases of Candida auris increased 59% from 2019 to 2020 and 95% from 2020 to 2021.
• The number of C. auris cases with resistance to echinocandins was about three times higher in 2021 than in 2019 and 2020.

Candida auris cases and transmission have dramatically increased in recent years, with 17 states identifying their first case from 2019 to 2021, according to a study published in Annals of Internal Medicine.

C. auris was first reported in the United States in 2016, Meghan Lyman, MD, a medical officer at the CDC, and colleagues wrote. Many early cases reflected transmission from abroad. However, recent cases have originated primarily through local transmission, particularly in long-term acute-care hospitals (LTACHs) and ventilator-capable skilled-nursing facilities.

“In recent years, reports of infections that are associated with health care or caused by multidrug-resistant organisms (MDROs) have increased,” the researchers wrote.

For the study, Lyman and colleagues examined recent changes in the epidemiology of C. auris. They utilized clinical and screening C. auris data that were reported to state and local health departments, as well as the CDC, from 2013 through 2021. The researchers also analyzed cases of drug-resistant Candida using data from the CDC’s Antimicrobial Resistance Laboratory Network.

Lyman and colleagues identified 3,270 clinical cases and 7,413 screening cases of C. auris during the study period. There were 53 clinical cases in 2016, “the year in which cases were first reported,” the researchers wrote. By 2018, the annual number of cases increased to 330. The case count grew each year, by 44% in 2019 (n = 476), to 59% to in 2020 (n = 756) and then by 95% in 2021 (n = 1,471).

There were similar rises in screening cases, which increased by 21% in 2020 (n = 1,310) and then by 209% in 2021 (n = 4,041).

C. auris also spread geographically. The number of new states impacted was eight in 2021 compared with six in 2019 and two in 2018.

Although echinocandin resistance remains uncommon across all geographic areas, Lyman and colleagues found that the number of C. auris cases with such resistance steadily increased, from three detected cases in 2020 to 19 detected cases in 2021.

“Even this subtle increase is concerning because echinocandins are the first-line therapy for invasive Candida infections and most C. auris infections,” they wrote. “Several new antifungal medications are in development, but more research is needed to understand outcomes for patients with these highly resistant strains and to guide treatment.”

The researchers said there are “multifactorial” reasons for the increase in C. auris cases, pointing to insufficiencies in the detection of early cases and the implementation of infection prevention and control measures. They also suggested that the strain on the health care system caused by COVID-19 may have widened gaps in infection control, “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 measures.”

Lyman and colleagues concluded that C. auris “remains an ongoing health threat,” but moving forward, “mitigation and even regional containment are possible, as facilities have shown that C. auris transmission can be controlled.”

“Targeting interventions to the weakest links in the health care system's infection control network, specifically LTACHs and ventilator capable skilled-nursing facilities, will have benefits beyond C. auris, including reducing the spread of other MDROs and improving preparedness for future epidemics,” they wrote.