What you need to know about C. auris, a rare but potentially deadly fungus

Candida auris (C. auris) is a multidrug-resistant fungus responsible for a rising number of infections and deaths around the world. Spread primarily in the health care setting, it is a growing threat to high-risk patients in hospitals, nursing homes, and other health care facilities. The CDC estimates that between 30% and 60% of people who become ill with C. auris infections have died.

Global mortality rates approach 60 percent for Candida auris infections among chronically ill patients.

As of a June 2019 CDC case count, there were 725 confirmed cases and 30 probable cases identified in 12 U.S. states. An additional 1,207 patients were found to have C. auris on their body but did not develop an infection. Only 13 cases were reported in the U.S. between 2013 and 2016.

“Typically when Candida infections are known or suspected, treatment and containment are reasonably straightforward,” says Gerald Blackburn, DO, an infectious disease specialist in Farmington Hills, Michigan. “What makes the higher rates of C. auris most concerning is its resistance to common antifungal treatments.”

The resilient fungus can survive for weeks on both skin and dry surfaces, such as bedrails and chairs, allowing it to move easily from person to person in health care settings, including in some of the most prestigious hospitals in the country.

Uncommon drug resistance

Most strains detected so far are resistant to at least one antifungal drug and more than one-third were resistant to two. Particularly worrisome, some strains are resistant to all three drug classes used to treat fungal infections.

Diagnosis can also be delayed because it is not easily identified by labs unless specifically looked for, leading to spread from one hospital to other affiliated facilities.

Those at highest risk for C. auris infection include patients in intensive care units for extended periods of time, including the chronically ill, transplant recipients, or cancer patients, all of whom are likely to have had multiple life-supporting devices placed, including intravenous catheters, urinary catheters, breathing tubes, pacemakers, etc., and most of whom have been on multiple antibiotics for prolonged periods of time. These devices are most likely to host the fungus and can be difficult to disinfect.

“Our concern within the medical community currently is focused on the sickest of the sick,” Dr. Blackburn says. “C. auris is much less likely to affect a healthy person, or even an individual whose stay in the hospital is limited.”

Action needed

The CDC has issued a clinical alert to help stop the widespread of C. auris in medical facilities. Managing the fungus will require an aggressive response and a clear understanding of the most effective ways to prevent transmission.
Existing conventional or outdated lab techniques in some health care facilities may lead to misidentification and ineffective treatment. Specialized laboratory methods are necessary to accurately identify and minimize the spread of C. auris.

“Patients should know that hospitals around the country are moving swiftly to address this new strain, but, even so, we can anticipate that this drug-resistant fungus will impact more patients over time,” says Dr. Blackburn. “Moreover, I worry that this newly recognized fungus is another harbinger of the serious problems that stem from our widespread and sometimes too casual use of antibiotics.”

Should C. auris become one of the strains that contribute to yeast infections in healthier people, such as thrush or vaginal infections, then a much larger population will be impacted, says Dr. Blackburn.