MADRID – The anticipated global emergence of multidrug resistant Candida auris is now an established fact, but a case study presented at the European Society of Clinical Microbiology and Infectious Diseases annual congress demonstrates just how devastating an outbreak can be to a medical facility and its surgical ICU patients.
The dangerous invasive infection is spreading through Asia, Europe, and the Americas, causing potentially fatal candidemias and proving devilishly difficult to eradicate in health care facilities once it becomes established.
Several multidrug resistant (MDR) C. auris outbreaks were reported at the ECCMID meeting. Most troubling: a continuing outbreak in a hospital in Valencia, Spain, in which 17 patients have died – a 41% fatality rate among those who developed a fulminant C. auris candidemia, Javier Pemán, MD, said at the meeting. The strain appeared to be a clonal population not previously identified in published reports.
“C. auris is hard to remove from the hospital environment,” once it becomes established, said Dr. Pemán of La Fe University and Polytechnic Hospital, Valencia. “When an outbreak lasts for months, as ours has, it is difficult, but necessary, to maintain control measures, identify it early in the lab, and isolate and treat patients early with combination therapy.”
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Dr. Javier Pemán
He and his team have relied primarily on a combination of amphotericin B and echinocandin (AMB+ECN), although, he added, the optimal dosing and treatment time aren’t known, and many C. auris isolates are echinocandin resistant.
MDR C. auris first appearedin Tokyo in 2009. It then spread to South Korea around 2011, and then appeared across Asia and Western Europe. Its first appearance in Spain was the 2016 Le Fe outbreak.
According to the Centers for Disease Control and Prevention, single cases have appeared in Austria, Belgium, Malaysia, Norway, and the United Arab Emirates. Canada, Colombia, France, Germany, India, Israel, Japan, Kenya, Kuwait, Oman, Pakistan, Panama, South Korea, South Africa, Spain, the United Arab Emirates, the United Kingdom, and Venezuela have experienced multiple outbreaks.
The CDC has recorded 257 confirmed and 30 probable cases of MDR C. auris in the United States as of March 31, 2018. Most of these occurred in New York City and New Jersey; a number of patients had recent stays in hospitals in India, Pakistan, South Africa, the UAE, and Venezuela.
Jacques Meis, MD, of the department of medical microbiology and infectious diseases at Canisius Wilhelmina Hospital, Nijmegen, the Netherlands, set the stage for an extended discussion of C. auris at the meeting.
“This is a multidrug resistant yeast that has emerged in the last decade. Some rare isolates are resistant to all three major antifungal classes. Unlike other Candida species, it seems to persist for prolonged periods in health care environments and to colonize patients’ skin. It behaves rather like resistant bacteria.”
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Dr. Jacques Meis
Once established in a health care setting – often an intensive care ward – C. auris poses major infection controls challenges and can be very hard to identify and eradicate, said Dr. Meis.
The identification problem is well known. The 2016 CDC alert noted that “commercially available biochemical-based tests, including API strips and VITEK-2, used in many U.S. laboratories to identify fungi, cannot differentiate C. auris from related species. Because of these challenges, clinical laboratories have misidentified the organism as C. haemulonii and Saccharomyces cerevisiae.”
“It’s often misidentified as other Candida species or as Saccharomyces when we investigate with biochemical methods. C. auris is best identified using Matrix Assisted Laser Desorption/Ionization time of flight mass spectrometry (MALDI-TOF),” said Dr. Meis.
Among the presentations at ECCMID were a report of a U.K. outbreak that affected 70 patients in a neuroscience ICU. It was traced to axillary skin-surface temperature probes, and eradicated only after those probes were removed. More than 90% of the isolates were resistant to fluconazole, voriconazole, and posaconazole; 18% were amphotericin resistant.
A poster described the microbiological characteristics of 50 C. auris isolates taken from 11 hospitals in Korea.
Dr. Pemán described the outbreak in Valencia, which began in April 2016; the report was simultaneously published in the online journal Mycoses (2018 Apr 14. doi: 10.1111/myc.12781).
The index case was a 66-year-old man with hepatocellular carcinoma who underwent a liver resection at Hospital Le Fe in April 2016. During his stay in the surgical ICU (SICU), he developed a fungal infection from an unknown, highly fluconazole-resistant yeast. The pathogen was twice misidentified, first as C. haemulonii and then as S. cerevisiae.
Three weeks later, the patient in the adjacent bed developed a similar infection. Sequencing of the internal transcribed spacer confirmed both as a Candida isolate – an organism previously unknown in Spain.
The SICU setup was apparently very conducive to the C. auris life cycle, Dr. Pemán said. It’s a relatively open ward divided into three rooms with 12 beds in each. There are no isolation beds, and dozens of workers have access to the ward every day, including clinical and cleaning staff.