Global Emergence of Multidrug-Resistant Yeast Candida auris causing Invasive Infections
June 28 2016
The Centre for Communicable Diseases (CDC) is alerting U.S. healthcare facilities to be on the lookout for Candida auris in their patients having received reports from international healthcare facilities, that this emerging multidrug resistant yeast is causing invasive infections with high mortality.
There is particular concern because it is often multidrug resistant, it is difficult to identify with standard laboratory methods and it has already caused outbreaks in hospital settings.
C. auris can enter the bloodstream and spread throughout the body, causing serious invasive infections & often does not respond to commonly used antifungal drugs, making infections difficult to treat. Some strains of C. auris have elevated minimum inhibitory concentrations (MICs) to the three major classes of antifungals, severely limiting treatment options. No MIC breakpoints exist for C. auris – but testing of an international collection of isolates demonstrated that they were nearly all highly resiistant to fluconazole, more than half of isolates were voriconazole resistant , one third were amphotericin B resistant and a few to echinocandins. Alarmingly some isolates showed elevated MICs to all three major classes of antifungals.
Since 2009, C. auris has been found in patients in nine countries, including the United States, and it has been reported to cause bloodstream infections, wound infections, and otitis, it has also been cultured from respiratory samples and urine, but it is not known if these are infection sites or due to colonization. A very recent report of C. auris from a hospital in Venezuela isolated from 18 critically ill patients, 11 of which were neonates has been highlighted (view).
Patients who have been in the intensive care unit for a long time or have a central venous catheter placed in a large vein, and have previously received antibiotics or antifungal medications, appear to be at highest risk of this infection.
Specialized laboratory methods are needed to accurately identify C. auris as standard API strips and VITEK-2 tests cannot distinguish between this and other Candida spp. Conventional lab techniques could lead to mis-identification and inappropriate treatment, making it difficult to control the spread of C. auris in healthcare settings.
The CDC is recommending use of MALDI-TOF or molecular sequencing to Identify this species in the laboratory and to follow stringent infection control and environmental cleaning (view more detailed information).