UNC Charlotte expert shares what you need to know about Candida auris

The United States is seeing a rapid increase of cases of Candida auris, a fungus found in health care facilities, according to the U.S. Centers for Disease Control and Prevention. Morgan Carter, assistant professor in the Klein College of Science, answered questions about the fungus and its impacts.

What is Candida auris and how does it spread?

Candidozyma (Candida) auris is a single-celled fungus—part of the organism family that includes mushrooms and brewer’s yeast. However, C. auris can live at temperatures as high as human body temperature and survives for weeks to months on surfaces around the built environment, spreading as different people touch those surfaces. Though microscopic, it’s surprisingly sticky! These qualities make it a risky human pathogen, unlike the yeast in beer and bread.

Why is the fungus specifically found in health care facilities?

C. auris is introduced to health care facilities by hitching a ride on humans, whether they are symptomatic or not. It can colonize the skin without a person knowing, or create a symptomatic infection affecting the bloodstream or other internal location. Interestingly, researchers are still looking into where C. auris exists in the natural environment as it emerged quite recently as a human pathogen. But infections are generally considered to be acquired from health care facilities/other humans, not the natural environment.

Who is most at risk for being impacted by Candida auris?

This would really fall into three categories that may overlap: immunocompromised individuals, those getting invasive procedures and those in long-term care facilities.

Immunocompromised individuals: The human immune system does a pretty good job at fighting off fungal diseases, but if someone is already sick from another infection, condition (cancer, diabetes, etc), or treatment (like before organ transplant), then it will be harder for their body to fight off C. auris.

Individuals getting invasive procedures: Surgical site wounding, central venous lines, urinary catheters, and breathing/feeding tubes are all examples of invasive procedures or devices that can introduce C. auris into the body jump-starting an infection.

Individuals in long-term care facilities: It is difficult to keep everything perfectly clean between patients with limited health care professionals to staff these facilities, who are constantly moving from patient to patient and room to room. Essentially, the longer you are exposed to a high-risk setting, the more opportunity for exposure to the fungus, especially once a single case is detected in a facility.

What are the symptoms if you become infected?

The symptoms vary depending on where the infection is, but are not easily distinguishable from other infections at the early stages, leading to later diagnoses that can result in worse disease outcomes. Typical symptoms include fever and chills, and these will not resolve if one takes antibiotics as those target bacteria, not fungi. However, skin colonized with C. auris may have no symptoms.

How is Candida auris treated?

Current best practices are to use echinocandins as the first round of treatment, but we are seeing more cases where C. auris is resistant to this drug group. In fact, one of the major concerns with C. auris is that it is highly resistant to many common antifungals, necessitating the use of experimental treatments still in development. Not only can it become resistant while being treated with a drug, but it may start an infection already resistant, rendering treatment with that drug ineffective from the beginning. Though we may not look very similar, our cells have a lot in common with fungal cells, so it is difficult to design drugs to target fungi that don’t hurt us. Because of this, the mortality rate for invasive infections is very high, but this is likely affected by coexisting conditions as well.

Since Candida auris can resist certain cleaning products, what can be done to disinfect impacted areas?

The CDC recommends the use of alcohol-based disinfectants for hand hygiene to counter C. auris and the EPA does maintain a list of effective products. These include hydrogen peroxide and sodium hypochlorite (the active chemical in bleach) based products, but they require a contact time of a few minutes to work effectively. A key tool for pathogen control is screening to see if the pathogen is present by doing routine testing of surfaces and patients’ skin before an outbreak occurs. However, this can be difficult to maintain in understaffed or busy facilities, and colonized individuals can carry the yeast for years.

What else should the general public know about Candida auris?

What’s in a name? One additional thing that has made C. auris confusing to track as it has emerged as a pathogen, is simply what to call it. The name “Candida” has been applied to many yeasts over the years, even when they aren’t that close genetically and may need to be treated differently. They look pretty similar under a microscope!

Though still popularly referred to as “Candida,” the medical mycology community recently reclassified it as Candidozyma auris to be more descriptive and specific. Though this can sometimes be confusing to patients or practitioners, accurately describing an organism or disease can help us more clearly discuss the problem and identify solutions for affected patients.

Written by: Morgan Carter and Andrew James