A week ago the CDC issued a Clinical Alert to U.S. Healthcare facilities about the Global Emergence of Invasive Infections Caused by the Multidrug-Resistant Yeast Candida auris.
An emerging fungal pathogen – C. auris was first isolated about 7 years ago in Japan, found in the discharge from the patient's external ear (hence the name `auris').
Since then there have been a small, but growing, number of cases (and hospital clusters) reported internationally, generally involving bloodstream infections, wound infections or otitis.
Unlike most systemic Candida infections, which usually arise when a previously colonized person is weakened from illness or infirmity, this strain appears to have a propensity for nosocomial transmission.
When you add in that:
- C. auris infections have a high fatality rate
- The strain appears to be resistant to multiple classes of anti-fungals
- And it can be difficult for labs to differentiate between Candida strains
Candida auris is an emerging multidrug-resistant (MDR) yeast that can cause invasive infections and is associated with high mortality. It was first described in 2009 after being isolated from external ear discharge of a patient in Japan 1. Since the 2009 report, C. auris infections, specifically fungemia, have been reported from South Korea 2, India 3, South Africa 4, and Kuwait 5. Although published reports are not available, C. auris has also been identified in Colombia, Venezuela, Pakistan, and the United Kingdom.
Yesterday Public Health England finally unveiled the details of C. auris detections in the UK, including a large (and ongoing since April 2015) nosocomial outbreak at an adult critical care unit in England.
Research and analysis
Candida auris identified in England
Published 1 July 2016
Sporadic cases of C. auris have been identified throughout England since August 2013, with a total of 12 isolates among 8 patients sent to the Public Health England (PHE) Reference Mycology Laboratory.
Since April 2015, an adult critical care unit in England has been managing an outbreak of C. auris, with more than 40 patients either colonised or infected; approximately 20% with candidaemia.
The hospital outbreak has been difficult to control, despite enhanced infection control interventions, including regular patient screening, environmental decontamination and ward closure.
In addition, 2 further positive isolates have been identified at the PHE Reference Mycology Laboratory in 2016 which were submitted from another hospital in a different region; investigations are ongoing to identify if there are any further cases. Of note, one of these isolates is phenotypically distinct to the outbreak strain.
On 27 June 2016, PHE alerted healthcare providers, including microbiologists and infection prevention and control personnel, to the emergence of this fungal pathogen. In addition, guidance was publish for the laboratory investigation, management and infection prevention and control of cases of Candida auris .
See the clinical Candida auris guidance published by Public Health England for further recommendations.
It seems probable that now that both the CDC and PHE have issued warnings and guidance that we'll be hearing a lot more about this emerging pathogen from around the globe.
As we've seen with NDM-1 and the recently discovered MCR-1 resistance genes, it is likely that this Candida strain is more widespread than is currently appreciated.
Although no outbreaks have been reported in the United States, the CDC is concerned that it is only a matter of time. They have offered the following interim recommendations:
CDC is concerned that C. auris will emerge in new locations, including the United States. CDC and partners continue to work closely, and new information will be provided as it becomes available. CDC recommends the following actions for U.S. healthcare facilities and laboratories:
- Reporting — Healthcare facilities who suspect they have a patient with C. auris infection should contact state/local public health authorities and CDC (email@example.com).
- Laboratory Diagnosis — Diagnostic devices based on matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) can differentiate C.auris, but not all devices currently include C. auris in the reference database to allow for detection. Molecular methods based on sequencing the D1-D2 region of the 28s rDNA can also identify C. auris. CDC requests that laboratories identifying C. auris isolates in the United States notify their state or local health departments and CDC (firstname.lastname@example.org). C. haemulonii isolates and other isolates from clinical specimens that cannot be identified beyond Candida spp. by conventional methods can be forwarded through state public health laboratories to CDC for further characterization.
- Infection Control — Until further information is available, healthcare facilities should place patients with C. auris colonization or infection in single rooms and healthcare personnel should use Standard and Contact Precautions. In addition, state or local health authorities and CDC should be consulted about the need for additional interventions to prevent transmission. CDC is working with domestic and international partners to develop definitive infection control guidance.
- Environmental Cleaning – Anecdotal reports have suggested that C. auris may persist in the environment. Healthcare facilities who have patients with C. auris infection or colonization should ensure thorough daily and terminal cleaning and disinfection of these patient’s rooms using an EPA-registered hospital grade disinfectant with a fungal claim.