REPORTING FROM ID WEEK 2017
SAN DIEGO (FRONTLINE MEDICAL NEWS) – The rise of Candida auris as a superbug represents a paradigm shift, because, in the words of Dr. Tom M. Chiller, it’s a yeast that acts like a bacteria.
“Treatment resistance is now the norm,” Dr. Chiller, chief of the mycotic diseases branch at the Centers for Disease Control and Prevention, Atlanta, said an annual scientific meeting on infectious diseases. “It thrives on skin, it contaminates patient rooms, and it spreads readily in health care settings.”
Since it was first described in Japan in 2009, C. auris has been identified in multiple countries in four continents, including the United States, prompting the CDC to issue a clinical alert to health care facilities in June of 2016. To date, more than 130 cases have been reported in 10 states, mostly in New York and New Jersey. At the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society, Dr. Chiller said that C. auris is a challenging superbug for four main reasons:
It’s not easily identified
Matrix assisted laser desorption ionization–time of flight (MALDI-TOF) or DNA sequencing are required to make the diagnosis. “It turns out that only about 25% of clinical labs have MALDI-TOF available, so we’re still lacking in our ability to identify it,” he said.
It’s easily transmitted
C. auris “is really happy in a hospital room,” Dr. Chiller said. “You can grow it from the floor, on the bottom of shoes, and on hand alcohol dispensers. It also likes the skin, and it also likes to grow in slightly higher temperatures. You find it readily in the axilla and groin. Those are the main locations we’re using for developing screening culture techniques.”
It’s difficult to treat
Treatment, if clinically indicated, includes an echinocandin such as micafungin, anidulafungin, and caspofungin at standard dosing. However, there have been cases of development of resistance to echinocandins while on therapy. “That bothers me,” Dr. Chiller said. “We don’t like to see that happen, and I am concerned. These bugs are really happy to be resistant, but based on the epidemiology, we remain convinced that it’s important to treat with an echinocandin.”
It can cause severe invasive disease and death
Global epidemiologic evaluation of the first 50 or so cases found that some patients were on antifungal treatment when C. auris was isolated. The mortality was greater than 60%, and there was a clustering in some hospitals. “Some hospitals reported that up to 40% of candidemia cases were from C. auris,” he said.
Among cases in the United States to date, the median age of affected patients is 70 years and patients’ 30-day mortality is about 30%. “They were quite ill, with multiple underlying conditions and indwelling devices,” Dr. Chiller said. They had “extensive health care exposure” with stays in acute care hospitals and nursing homes with ventilator units, and several recent cases with travel and health care exposures abroad, mainly to India, Pakistan, Venezuela, and South Africa.
According to Dr. Chiller, clinicians should suspect C. auris if yeast is identified as Candida haemulonii, Candida famata, Candida sake, Rhodotorula glutinis (without characteristic red color in the lab), or if they’re unable to further speculate after a validated method of Candida identification is attempted. C. auris also should be suspected in cases of resistance to one or more antifungal drugs and if Candida is isolated from any body site in a patient with recent travel, especially if they received health care in a country reporting the superbug. C. auris can be accurately identified using MALDI-TOF (with C. auris in reference database) and DNA sequencing.
Clinicians should report suspected cases to their local health department or to the CDC at email@example.com .
“We also want them to implement and reinforce infection control measures,” Dr. Chiller advised. “Get the lab to review other potential Candida cases or Candida species you might have. Conduct contact tracing to identify other colonized patients, and consider point-prevalence surveys.”
He reported having no financial disclosures.