Tom Chiller, MD: Clinical Overview of Candida auris
OCTOBER 05, 2017
Tom Chiller, MD, MPH, Mycotic Diseases Branch, Centers for Disease Control and Prevention: Candida auris is an emerging species of Candida that we're quite concerned about. It's a typical yeast but it's acting like a bacteria, and so it has qualities that we don't typically see in organisms that cause disease by Candida species. The main one being Candidemia, which is the invasive form or the bloodstream form of Candidiasis. This organism, this specific species, is acting quite differently when it's causing invasive infections.
We first heard and saw reports about Candida auris in 2009. It was actually reported in Japan in the external ear canal of a patient, that's why it gets the name auris because auris is the Latin for ear. Subsequently now we've seen it being reported across the globe and it's in over 20 countries, it's on 4 or 5 different continents now and it really has emerged over these last 7 or 8 years, and that's not typical for a Candida type species, especially to emerge almost simultaneously across 4 continents. So when we first heard about its emergence in 2009 we started to communicate with other colleagues who were seeing patients globally, and finally we were talking to colleagues in Pakistan who were witnessing an outbreak in a hospital that they thought was due to one kind of fungus and it turns out when we received the fungal isolates at CDC we were able to identify it actually as this Candida auris. What's the problem with Canada auris? Well number one Canada auris is challenging to identify, that hospital in Pakistan did not identify it correctly so that typical biochemical ways of identifying fungal species don't work with this particular species, you need to sequence it or use higher tech equipment, MALDI Tov is the name of the equipment that we use. Secondly, it is resistant to the classes of antifungal drugs that we use. We have 3 classes of antifungal drugs. We often see Canada auris resistant to at least 1, many times 2 and even in rare cases we've seen all 3 classes of resistance in these organisms which makes them essentially untreatable, and we call it therefore the fungal super bug right now because we're concerned that the triple resistance will be untreatable. And then third and most challenging, is that it's not acting like a Candida, as I mentioned earlier, it's acting more like a bacteria in the fact that it's transmitted person-to-person, it's transmitted within healthcare settings. And most Candida infections that we have, actually come from our own intestinal tract and it's sort of like an auto infection. We generally bring the organisms in with ourselves to hospitals where we then infect ourselves because we're exposed to the healthcare environment, antibiotics, equipment etc. With this particular species it doesn't need that, it seems to be colonizing our skin and is actually transmitted like a bacteria — like bacteria that we deal with the hospitals, from person to person and in healthcare settings.