I’ve written this post in preparation for tomorrow’s Journal Club, which will be based on this NEJM review of Candidozyma auris (formerly Candida auris). You can register for Journal Club here (or watch the recording afterwards here).

Why I chose this article:

• C. auris is an emerging fungal pathogen that is beginning to cause issues in healthcare systems around the world.
• The main challenge with C. auris is resistance to key antifungal agents, meaning that treatment options for infections are increasingly limited.
• There is recent evidence that C. auris is emerging rapidly in the USA, UK, and in other parts of Europe.

Key takeaways about C. auris:

• Candida auris has recently changed its name to Candidozyma auris (why do they do this?!).
• C. auris is a fungal opportunistic pathogen.
• C. auris most commonly colonised humans but can cause infections. C. auris candidaemia and invasive candidiasis can be life-threatening, with crude mortality in the 30-60% bracket but it’s difficult to determine attributable mortality.
• Risk factors for colonisation or infection with C. auris are similar to antibiotic resistant bacteria such as CPE: age, devices/ventilation, underlying medical conditions, surgical interventions, medicines (including antimicrobial agents and steroids).
• C. auris is very able to colonise human skin and surfaces of medical devices and other surfaces.
• Most strains of C. auris are resistant to fluconazole, and some strains are resistant to all available classes of antifungal drugs.
• C. auris has spread globally, affecting at least 45 countries. For example, a recent study from Saudi Arabia tracked the emergence of C. auris to become the predominant cause of HCAI outbreaks in recent years.
• From an IPC viewpoint, rapid identification combined with timely application of IPC measures is the cornerstone of prevention.

Points for discussion:

• Who do we screen and how do we screen them? Patients with a history of C. auris infection or colonisation should be prioritised for screening (and I wouldn’t really believe a negative screening result!). Generally speaking, patients who have been hospitalised overseas are going to be the highest risk. As to whether you consider patients who have been hospitalised in your country as a risk, that will depend where in the world you are, and how much C. auris has been seen in your locale! To complicate matters, there are some diagnostic challenges with accurately and rapidly detecting C. auris.
• How do we clean and disinfect the environment? We know that C. auris is shed into the environment, can survive for extended periods on dry surfaces, and surface contamination (especially shared medical equipment) has been implicated in transmission. The best example of this is the temperature probes at Oxford. So how do we clean and disinfected the environment? Most guidelines recommend reaching for a sporicidal agent (such as chlorine or peracetic acid), even though we are not dealing with bacterial endospores. There’s also a role for automated room decontamination systems to provide additional assurance around environment hygiene.  
• How long do patients remain colonised with C. auris? If only we knew for sure! There is some evidence that colonisation can be very prolonged. In one study, the median time from being serially positive to serially negative was around 9 months. But exactly how we define a “decolonised” state for C. auris is up for debate!
• Is there any effective decolonisation / suppression therapy? Short answer is no. Some recommend chlorhexidine daily bathing to reduce shedding of C. auris, but there’s not compelling evidence that this reduces cross-transmission.

What this means for IPC:

• Without wishing to be melodramatic, C. auris is very likely to be coming to a hospital near you in the near future, wherever you are in the world. And C. auris has very much arrived in some places, and is beginning to present substantial clinical and operational challenges. So now is a very good time to brush up on the latest guidance, establish an effective screening strategy that fits your context, and ensure that our workforce is aware of this emerging fungal threat!