April 9, 2019 -- Public health officials are closely tracking a new superbug. It’s a tough new strain of fungus called Candida auris, and it’s resistant to most of the drugs that are available to treat it. Studies estimate that about half of people who become infected with it will die. According to the latest update from the CDC, it has sickened 617 patients in hospitals, nursing homes, and long term care facilities in 12 states [GB1] .
We asked Tom Chiller, MD, Chief of the Mycotic Diseases Branch at the CDC for a situation report.
WebMD: When did doctors first become aware of Candida auris?
Chiller: Candida auris came into the published literature and knowledge in 2009, so relatively recent. It was first reported in the ear canal of a person in Japan.
WebMD: Most of us know candida from common yeast infections that you might get on your skin or mucous membranes. What makes this one different?
Chiller: It’s not acting like your typical candida. We’re used to seeing those.
Candida — the regular ones — are already a major cause of bloodstream infection in hospitalized patients. When we get invasive infections, for example, bloodstream infections, we think that you sort of auto-infect yourself. You come in with the candida already living in your gut. You’re in the ICU, you’re on a broad spectrum antibiotic. You’re killing off bad bacteria, you’re killing off good bacteria, so what are you left with? Yeast, and it takes over.
What’s new with Candida auris is that it doesn’t act like the typical candida that comes from our gut. This seems to be more of a skin organism. It’s very happy on the skin and on surfaces.
It can survive on surfaces for long periods of time, weeks to months. We know of patients that are colonized [meaning the Candida auris lives on their skin without making them sick] for over a year now.
It is spreading in health care settings, more like bacteria would, so it’s yeast that’s acting like bacteria.
WebMD: We read about a large outbreak—involving 70 patients--at a hospital in the U.K. where it was being passed from patient to patient on hospital thermometers.
Chiller: Yes. We’re able to see its spread once it sets up shop in a unit or a ward or a skilled nursing facility. We’re able to track that using whole genome sequencing.
In England they were dealing with a very large outbreak in a hospital in London. They’re the ones that alerted us to the fact of how hard this is to control and kill.
They would take a patient out of the room, try to clean the room, put a screened negative patient [who didn’t have any sign of C. auris] into that room and a couple of days later they would find Candida auris on the patient.
They could find it everywhere, on the windowsills, curtains, floor beds, machines, desks, chairs, shoes, so the yeast is able to go everywhere. It’s been very hard to kill in the environment and on a patient’s skin.
Bleach works well to kill it but you can’t bleach everything because bleach can damage hospital equipment, so there are other disinfectants that you can use and hospitals are having better success now.
WebMD: How concerned are you about this germ?
Chiller: I’m worried about this one. Candidemia is often the most common bloodstream infection in many hospitals and ICUs across this country. Thankfully we still have antifungals to treat those infections.
But Candida auris can be highly resistant to anti-fungal drugs. Thankfully, it has shown less resistance to the newest class of antifungals called the echinocandins. However, in rare circumstances, this organism has developed triple resistance or pan resistance [meaning it would be resistant to all currently approved antifungal drugs.]
The nightmare scenario for me is that this organism becomes the predominate species causing candidemia in this country, which as I’ve already told you is a leading cause of bloodstream infections in our hospitals and ICUs. That becomes a really bad scenario, and I’m concerned about that.
WebMD: Can you get a Candida auris infection at home? Or do you have to be in the hospital?
Chiller: It’s one of the things we’re looking into. It may be on people’s skin in the community. We don’t think it’s making people sick at home. Candida auris is a problem of the very sick, of the “medically experienced” patient.
WebMD: Do hospitals always know when they have a problem with this?
Chiller: Although the typical biochemical and blood culture testing that is done in most healthcare facilities does not identify Candida auris, many hospitals now have that capability, and if not, can access a lab that does. CDC can help identify if it is Candida auris or not.
WebMD: How long has it been since a new antifungal medical was developed? If it becomes pan-resistant, do we have anything to fight it?
Chiller: The newest class of antifungal drugs, the echinocandins, came out in the late 1990s. It’s been a good two decades since we’ve had a new antifungal class. The good news is there are a number of new drugs in the development pipeline, and some look promising against Candida auris.