Information for Laboratory Staff
Candida auris: A drug-resistant fungus that spreads in healthcare facilities
A CDC message to laboratory staff
Candida auris is a fungus that causes serious infections and spreads in healthcare facilities. Laboratory staff, healthcare personnel, and infection preventionists can all help prevent it from spreading.
Why is Candida auris a problem?
- It causes serious infections. C. auris can cause bloodstream and other types of invasive infections, particularly in patients in hospitals and nursing homes who have many medical problems. More than 1 in 3 patients die within a month of being diagnosed with an invasive C. auris infection.
- It is often multidrug-resistant. Antifungal medications commonly used to treat other Candida infections often don’t work for C. auris. Some C. auris isolates are resistant to all three major classes of antifungal medications.
- It is becoming more common. Although C. auris was just discovered in 2009, the number of cases has grown quickly. Since 2009, cases have been reported in dozens of countries, including the United States.
- It is difficult to identify. C. auris can be misidentified as other types of yeasts unless specialized laboratory methods are used. Correctly identifying C. auris is critical for starting measures to stop its spread and prevent outbreaks.
- It can spread and cause outbreaks in healthcare facilities. Just like other multidrug-resistant organisms such as carbapenem-resistant Enterobacteriaceae (CRE) and methicillin-resistant Staphylococcus aureus (MRSA), C. auris can be transmitted in healthcare settings and cause outbreaks. It can colonize patients for many months, persist in the environment, and withstand some commonly used healthcare facility disinfectants.
Prepare for C. auris identification
Early detection can help limit spread of C. auris.
- Some phenotypic methods for yeast identification can misidentify C. auris as a number of different organisms.
- C. auris is often misidentified as Candida haemulonii, another rare yeast, but misidentifications depend on the lab methodology used.
- Know whether the yeast identification method used in your laboratory misidentifies C. auris and, if so, what the possible misidentifications are. See https://www.cdc.gov/fungal/candida-auris/identification.html for common misidentifications by method.
- Misidentification can lead to inappropriate patient treatment and delay appropriate infection control precautions.
- There are no phenotypic characteristics that can easily distinguish C. auris from other Candida species.
- The most reliable way to identify C. auris is matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).
- If you have a MALDI-TOF MS in your lab, ensure that C. auris is included in the database.
- Molecular methods based on DNA sequencing can also identify C. auris. Accepted methods include sequencing of the D1-D2 region of the 28s ribosomal DNA (rDNA) or the internal transcribed spacer (ITS) region of rDNA.
- Some labs have recently been successful implementing qPCR methods, which provide the fastest test results at this time.
- Validate your instrument to confirm it can identify C. auris. If needed, use isolates from wwwn.cdc.gov/ARIsolateBank/.
- Work with your facility’s infection preventionist to set up a plan for informing them about possible or confirmed C. auris and subsequent notification of public health authorities.
- Work with your state and local public health department for further characterization of these isolates. The health department will determine whether additional outreach to the Antibiotic Resistance Laboratory Network or CDC is needed.
What should I do if C. auris is confirmed?
- Report possible or confirmed C. auris cases immediately to your facility’s infection prevention and control department and follow your facility’s process for reporting to public health departments.
- Conduct antifungal susceptibility testing.
- Look for other cases of C. auris in your facility:
- Review microbiology records to find potentially missed cases.
- Begin surveillance for C. auris from clinical specimens to identify new cases.
- C. auris is found in many body sites and fluids, including blood, respiratory, and abdominal specimens.
- Consider identifying the species of Candida isolates from both sterile and non-sterile sites, even if this is not routine practice at your facility. Continue surveillance for at least one month or until there is no evidence of transmission.
More guidance on when to suspect C. auris, how to correctly identify C. auris, and suggested antifungal drug minimum inhibitory concentration (MIC) cutoff values are available on CDC’s web pages for
- Identification of C. auris: https://www.cdc.gov/fungal/diseases/candidiasis/identification.html
- Antifungal Susceptibility Testing and Interpretation: https://www.cdc.gov/fungal/candida-auris/c-auris-antifungal.html.
For more information, please contact the Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Division of Foodborne, Waterborne, and Environmental Diseases
1600 Clifton Road, NE, Mail Stop H24-9, Atlanta, GA 30329-4018