Candida auris is an emerging fungal pathogen – a yeast species first isolated from the external ear of a patient in Japan in 2009 . Since then C. auris has been associated with bloodstream infections, wound infections and otitis. It has also been cultured from urine and the respiratory tract, although it is not known if positive cultures from these sites represent infections or colonisations .
Infections, including candidaemia, caused by C. auris have been reported in Japan , South Korea [3,4], South Africa , Kuwait , India , Pakistan , Venezuela , Colombia  and now the UK. With hospital outbreaks confirmed in 5 of these countries; C. auris appears to be unlike other pathogenic yeast species in its propensity for transmission between hospital patients. Molecular typing of many of the international strains performed by the US Centers for Disease Control and Prevention (CDC) suggests that isolates are highly related within countries and regions but distinct between continents .
Although there are no official breakpoints for antifungal susceptibility testing of this species, applying those derived from infections with other Candida species, resistance to fluconazole was common in isolates internationally  and in all those isolated to date from the UK. However, resistance to the 3 main classes of antifungal drugs (azoles, echinocandins and polyenes) has been described. As this species can evolve rapidly to develop resistance, susceptibility testing is recommended on all isolates from invasive disease and should be repeated on later isolates if infection persists despite treatment.
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.
C. auris isolates can be misidentified by commercial testing kits and equipment, most commonly as Candida haemulonii, Rhodotorula glutinis or Saccharomyces cerevisiae so further work is advised if those species are identified, to ensure that they are not C. auris. . This would involve either molecular sequencing of the D1/D2 domain or MALDI-TOF Biotyper analysis with C. auris either already present, or added to, the database . In addition, the reference code for C. auris was only included in PHE’s Second Generation Surveillance System (SGSS) in February 2016. Consequently, we do not currently have data to provide a background prevalence level of C. auris in the UK.
Therefore, it is important that any Candida spp. isolates associated with invasive infections and isolates from superficial sites in patients from high intensity settings and those transferred from an affected hospital (UK or abroad) should be analysed to species level. As knowledge on the epidemiology and prevalence in the UK is as yet limited, PHE is currently not in a position to make specific recommendations with regards to screening policy. However, C. auris screening could be considered for patients at risk for Candida disease (ESCMID guidance developing group define such patients as “[…] mainly ICU patients, paediatric, HIV/AIDS and patients with malignancies including haematopoietic stem cell transplantation.”) .
Many local microbiology services will not have the facilities to test at this level and will have to refer onwards to their PHE Network Laboratory or to the PHE Mycology Reference Laboratory.
In addition, it is of the utmost importance that local and PHE Network Laboratories should check that they have a local LIMS code for C. auris, and then check that this code is mapped to the new separate organism code for C. auris in SGSS.
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.
- Satoh K, Makimura K, Hasumi Y, Nishiyama Y, Uchida K, Yamaguchi H. Candida auris sp. nov., a novel ascomycetous yeast isolated from the external ear canal of an inpatient in a Japanese hospital. Microbiology and Immunology. 2009; 53(1): 41-4.
- [US] Centers for Disease Control and Prevention (24 June 2016). Global emergence of invasive infections caused by the multidrug-resistant yeast Candida auris.
- Kim MN, Shin JH, Sung H, Lee K, Kim EC, Ryoo N, et al (2009). Candida haemulonii and closely related species at 5 university hospitals in Korea: identification, antifungal susceptibility, and clinical features. Clinical Infectious Diseases: an official publication of the Infectious Diseases Society of America 48(6): e57-61.
- Lee WG, Shin JH, Uh Y, Kang MG, Kim SH, Park KH (2011). First 3 reported cases of nosocomial fungemia caused by Candida auris. J Clin Microbiol 49.
- Magobo RE, Corcoran C, Seetharam S, Govender NP (2014). Candida auris-associated candidemia, South Africa. Emerging Infectious Diseases. 20(7): 1250-1.
- Emara M, Ahmad S, Khan Z, Joseph L, Al-Obaid I, Purohit P, et al (2015). Candida auris candidemia in Kuwait, 2014. Emerging Infectious Diseases. 21(6): 1091-2.
- Kathuria S, Singh PK, Sharma C, Prakash A, Masih A, Kumar A (2015). Multidrug-resistant Candida auris misidentified as Candida haemulonii: characterization by matrix-assisted laser desorption ionization-time of flight mass spectrometry and DNA sequencing and its antifungal susceptibility profile variability by vitek 2, CLSI broth microdilution, and etest method. J Clin Microbiol 53.
- Messer SA, Moet GJ, Kirby JT, Jones RN (2009). Activity of contemporary antifungal agents, including the novel echinocandin anidulafungin, tested against Candida spp, Cryptococcus spp, and Aspergillus spp: report from the SENTRY Antimicrobial Surveillance Program (2006 to 2007). J Clin Microbiol 47(6): 1942-6.
- Ullmann AJ, Akova M, Herbrecht R, Viscoli C, Arendrup MC, Arikan-Akdagli S, et al (2012). ESCMID guideline for the diagnosis and management of Candida diseases 2012: adults with haematological malignancies and after haematopoietic stem cell transplantation (HCT). Clinical Microbiology and Infection 18 Suppl 7: 53-67.
- Public Health England (27 June 2016). Guidance for the laboratory investigation, management and infection prevention and control for cases of Candida auris.
This is an HPR Advance Access report published on 1 July 2016.