By Elizabeth Robilotti, MD, MPH
Assistant Attending Physician, Division of Infectious Diseases, Hospital for Special Surgery, New York, NY
SYNOPSIS: A recent report from the Centers for Disease Control and Prevention discusses the changing epidemiology of Candida auris between 2019 and 2021, including a 200% jump in screening cases from 2020 to 2021.
SOURCE: Lyman M, Forsberg K, Sexton DJ, et al. Worsening spread of Candida auris in the United States, 2019 to 2021. Ann Intern Med 2023;176:489-495.
The Centers for Disease Control and Prevention (CDC) released an update on the epidemiology of Candida auris from 2019 to 2021 in a recent issue of the Annals of Internal Medicine. C. auris, initially identified in the United States in 2016 after its global debut and connection to deadly outbreaks in other countries, is considered an “urgent threat” by the CDC because of its rapid dissemination, frequent resistance to first-line antifungal agents, and ability to cause severe disease, especially among immunocompromised patients.1
The CDC report highlights three key aspects of the changing epidemiology of C. auris that occurred since becoming nationally notifiable. These include: a transition from international case importation to endemic regional transmission; transmission across the interconnected healthcare continuum; and increasing antifungal resistance among recovered C. auris isolates. The report includes analysis of clinical cases, defined as C. auris isolates recovered from clinical specimens and screening cases identified from surveillance skin swabs. Clinical case counts demonstrated a stepwise increase from 53 (2016) to 1,471 (2021). Notably, probable cases have nearly disappeared owing to advances in testing. This was facilitated by expansion of the CDC’s Antimicrobial Resistance (AR) Laboratory Network, which increased access to molecular detection and culture-dependent identification methods to confirm recovery of C. auris and evaluate antifungal susceptibility.2
Screening cases also jumped more than 200% from 2020 to 2021 (1,310 to 4,041). Although there was a brief disruption of screening during the initial months of the COVID-19 pandemic, much of the increase in screening cases was due to expansion of surveillance programs and the positivity rate remained consistent at 8%.
After initial identification in the Northeast, California, and Illinois, 16 additional states identified C. auris cases from 2019 to 2021. Among states with case identification prior to 2018, the period from 2019-2021 was notable for an increase in local transmission networks tied to intra- and inter-facility transfers and is concentrated in high-acuity settings.
AR Laboratory Network identified overall 86% of isolates were resistant to azoles and 26% were resistant to amphotericin B. Significant regional variation was noted in resistance; for example, 99.5% of isolates from the Northeast region were azole-resistant vs. 10.9% from the Midwest. The differences are attributed to clade-specific resistance patterns tied to geographic C. auris circulation. Significant echinocandin resistance remains low (< 5%) but increased over 2021 per AR Laboratory Network.
The changing epidemiology of C. auris from 2019 to 2021 highlights the importance of robust diagnostic and surveillance testing for emerging multidrug-resistant pathogens for early reservoir identification and deployment of control measures. The COVID-19 pandemic had an impact on surveillance and control through disruption of routine infection control practices, supply chain issues, and workforce fatigue and attrition, which may have facilitated local transmission. Additionally, understanding key host-pathogen interactions that enable conversion from colonization to infection will be essential for combating the scourge of C. auris in the coming years.3
REFERENCES
- Vallabhaneni S, Kallen A, Tsay S, et al. Investigation of the first seven reported cases of Candida auris, a globally emerging invasive, multidrug-resistant fungus — United States, May 2013-August 2016. MMWR Morb Mortal Wkly Rep 2016;65:1234-1237.
- Centers for Disease Control and Prevention. CDC’s Antimicrobial Resistance (AR) Laboratory Networks. Page last reviewed Nov. 23, 2021. https://www.cdc.gov/drugresistance/laboratories.html
- Proctor DM, Drummond RA, Lionakis MS, Segre JA. One population, multiple lifestyles: Commensalism and pathogenesis in the human mycobiome. Cell Host Microbe 2023;31:539-553.
