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Volume 32, Number 2—February 2026
Letter
Candida auris Testing by the Antimicrobial Resistance Laboratory Network, United States, 2022–2023
Suggested citation for this article
Abstract
During 2022–2023, the Antimicrobial Resistance Laboratory Network tested 8,033 Candida auris clinical isolates in the United States. Overall, 95% of isolates were fluconazole resistant, 15% amphotericin B resistant, and 1% echinocandin resistant. Laboratory capacity for C. auris identification and antifungal susceptibility testing is essential to address this emerging public health threat.
Candida auris is an urgent public health threat because of frequent multidrug resistance, high transmissibility in healthcare settings, and association with high-mortality invasive infections (1–5). The Centers for Disease Control and Prevention Antimicrobial Resistance Laboratory Network (AR Lab Network) adopted C. auris testing, including antifungal susceptibility testing, in 2016 to meet clinical and public health needs (https://www.cdc.gov/antimicrobial-resistance-laboratory-networks/php/about/testing-services.html). National annual C. auris clinical case counts have increased from <100 in 2016 to >4,500 in 2023 (5,6). To inform prevention, clinical practice, and surveillance efforts, we describe 2022–2023 AR Lab Network C. auris clinical isolate testing.
Clinical C. auris isolates are obtained from patient specimens collected during clinical care, not for colonization detection, and can be from any body site (5). Isolates were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. MICs for fluconazole and echinocandins (anidulafungin, micafungin) were determined by using frozen custom broth microdilution panels and, for amphotericin B, by using gradient diffusion strip. According to tentative breakpoints (https://www.cdc.gov/candida-auris/hcp/laboratories/antifungal-susceptibility-testing.html), isolates were considered echinocandin-resistant if resistant to either echinocandin and panresistant if resistant to all 3 antifungal classes.
We examined the number of clinical isolates tested and antifungal susceptibility testing results by year, AR Lab Network region of specimen collection (https://www.cdc.gov/antimicrobial-resistance-laboratory-networks/php/about/domestic.html), and body site. We analyzed clinical specimens only to avoid biases from local screening intensity and protocol differences. We excluded specimens for which it was unclear whether they originated from colonization screening versus clinical isolates (≈14%).
During 2022–2023, a total of 8,033 clinical isolates were tested (Table). Most were from the West (24%), Southeast (21%), or Northeast (19%) regions; <1% were from the Central region. The number of clinical isolates increased from 3,064 in 2022 to 4,969 in 2023, increasing in all regions except the Mountain region (288 to 238). The most common body sites were blood (36%) and urine (32%). The distribution of body sites was similar across regions and years (data not shown).
Overall, 95% (7,244/7,594) of tested isolates were fluconazole-resistant; that percentage exceeded 90% in all regions except the Midwest (83%, 666/801) (Appendix). In total, 15% (1,128/7,458) of isolates were amphotericin B–resistant; that percentage was <5% in all regions except the Central (22%, 4/18), Northeast (44%, 629/1,420), and Mid-Atlantic (62%, 290/469). Fewer isolates were echinocandin-resistant (1%, 97/7,574); the highest percentages were in the Midwest (2%, 13/799), Northeast (2%, 31/1,420), and Mountain (3%, 14/463) regions. Overall, 16/7,438 (<1%) isolates were panresistant, mostly from the Northeast (n = 10).
Fluconazole resistance was higher in 2023 (96%, 4,441/4,616) than in 2022 (94%, 2,803/2,978); the largest differences were in the Midwest (90% [433/481] vs. 73% [233/320]) and Southeast (95% [906/957] vs. 90% [582/646]). Amphotericin B resistance was higher in 2023 (19%, 838/4,497) than in 2022 (10%, 290/2,961); the largest difference was in the Northeast (64% [508/794] vs. 19% [121/626]). Echinocandin resistance was 1% in both years, but in the Mountain region, it was higher in 2023 (7%, 13/187) than in 2022 (<1%, 1/276). Antifungal resistance was similar across body sites for fluconazole. More echinocandin-resistant isolates were from urine (3% [72/2,470] vs. <1% for each other site), and fewer amphotericin B–resistant isolates were from wounds or respiratory sites (10% [89/861] for wounds, 13% [99/761] for respiratory, vs. >15% each other site).
This analysis of AR Lab Network C. auris testing revealed a 1.5-fold increase in clinical isolate testing volume from 2022 to 2023, mirroring increases in national C. auris case prevalence. The proportion of clinical isolates tested by region generally mirrored regional proportions of national case counts (6). Fluconazole resistance rates were slightly higher in 2023 (96%) versus 2022 (94%) and were higher than in 2020 (86%), potentially because of increased circulation of fluconazole-resistant strains, primarily driven by isolates from the Midwest, where the fluconazole resistance rate was 90% in 2023 versus 11% during 2018–2020 (5). Amphotericin B resistance rates were higher in 2023 (19%) than in 2022 (10%) but were lower overall during 2022–2023 (15%) compared with 2020 (26%) (5). That finding might reflect lack of amphotericin B drug selection pressure, because maintaining resistance likely incurs fitness costs, or changes in circulating strains (7).
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. However, the number of resistant isolates has increased, and possible spread among patients has been documented (8,9). Echinocandin resistance was found more often in urine than in blood isolates (3% vs. 1%), which might relate to the limited urinary excretion of echinocandins (10).
AR Lab Network C. auris testing primarily supports local detection and outbreak response, rather than serving as nationally representative surveillance. Testing performed outside the network, an increasing proportion in recent years, is not captured. Data could not be analyzed at the patient level (including repeat isolates) and lacked information on antifungal exposure, clade, and facility type. Nonetheless, our findings highlight the persistence of C. auris as a multidrug-resistant threat requiring sustained investment in laboratory capacity for early detection and response.
Dr. Laury is a health scientist in the Mycotic Diseases Branch, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA. Her research interests include the epidemiology and prevention of fungal infections.
Acknowledgments
The authors thank Malavika Rajeev; the Antimicrobial Resistance Coordination and Strategy Unit Science Team; and the many federal, state, jurisdictional, and local partners who have contributed to the success of the AR Lab Network and who performed the extensive C. auris testing described in this report.
This activity was reviewed by the Centers for Disease Control and Prevention (CDC) and was conducted consistent with applicable federal law and CDC policy (e.g., 45 C.F.R. part 46, 21 C.F.R. part 56; 42 USC. §241(d); 5 USC. §552a; 44 USC. §3501 et seq). The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the CDC.
ChatGPT (OpenAI, https://chatgpt.com) was used for language editing of this manuscript; all intellectual content is the sole responsibility of the authors.
, and Meghan Lyman1
References
- Lockhart SR, Etienne KA, Vallabhaneni S, Farooqi J, Chowdhary A, Govender NP, et al. Simultaneous emergence of multidrug-resistant Candida auris on 3 continents confirmed by whole-genome sequencing and epidemiological analyses. Clin Infect Dis. 2017;64:134–40. DOIPubMedGoogle Scholar
- Benedict K, Forsberg K, Gold JAW, Baggs J, Lyman M. Candida auris‒Associated Hospitalizations, United States, 2017-2022. Emerg Infect Dis. 2023;29:1485–7. DOIPubMedGoogle Scholar
- Morales-López SE, Parra-Giraldo CM, Ceballos-Garzón A, Martínez HP, Rodríguez GJ, Álvarez-Moreno CA, et al. Invasive infections with multidrug-resistant yeast Candida auris, Colombia. Emerg Infect Dis. 2017;23:162–4. DOIPubMedGoogle Scholar
- Chakrabarti A, Sood P, Rudramurthy SM, Chen S, Kaur H, Capoor M, et al. Incidence, characteristics and outcome of ICU-acquired candidemia in India. Intensive Care Med. 2015;41:285–95. DOIPubMedGoogle Scholar
- Lyman M, Forsberg K, Sexton DJ, Chow NA, Lockhart SR, Jackson BR, et al. Worsening spread of Candida auris in the United States, 2019 to 2021. Ann Intern Med. 2023;176:489–95. DOIPubMedGoogle Scholar
- Centers for Disease Control and Prevention. Tracking C. auris [cited 2025 Apr 4]. https://www.cdc.gov/candida-auris/tracking-c-auris/index.html
- Carolus H, Sofras D, Boccarella G, Sephton-Clark P, Biriukov V, Cauldron NC, et al. Acquired amphotericin B resistance leads to fitness trade-offs that can be mitigated by compensatory evolution in Candida auris. Nat Microbiol. 2024;9:3304–20. DOIPubMedGoogle Scholar
- Centers for Disease Control and Prevention. Clinical treatment of C. auris infections [cited 2025 May 24]. https://www.cdc.gov/candida-auris/hcp/clinical-care/index.html
- Lyman M, Forsberg K, Reuben J, Dang T, Free R, Seagle EE, et al. Notes from the field: transmission of pan-resistant and echinocandin-resistant Candida auris in health care facilities—Texas and the District of Columbia, January–April 2021. MMWR Morb Mortal Wkly Rep. 2021;70:1022–3. DOIPubMedGoogle Scholar
- Felton T, Troke PF, Hope WW. Tissue penetration of antifungal agents. Clin Microbiol Rev. 2014;27:68–88. DOIPubMedGoogle Scholar
Figure
Table
Suggested citation for this article: Laury JE, Forsberg K, Berkow EL, Jones S, Sexton DJ, Sievert DM, et al. Candida auris testing by the Antimicrobial Resistance Laboratory Network, United States, 2022–2023. Emerg Infect Dis. 2026 Feb [date cited]. https://doi.org/10.3201/eid3202.251043
Original Publication Date: February 09, 2026
1These senior authors contributed equally to this article.
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Table of Contents – Volume 32, Number 2—February 2026
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Please use the form below to submit correspondence to the authors or contact them at the following address:
Jeremy A.W. Gold, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Mailstop H24-11, Atlanta, GA 30329-4018, USA
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