By Gary Evans, Medical Writer

A superbug that can become pan-resistant to fungal drugs, Candida auris first was reported in the United States in 2013 and continues to spread and cause hospital outbreaks.

First discovered in 2009 in Japan, the fungus continues to spread globally. This is an unusual bug in the world of fungi, in part because C. auris spreads more like bacteria. It can transmit to patients on the hands of healthcare workers, contaminate and persist in the environment, and colonize people, who then serve as a reservoirs. C. auris can cause high mortality rates, particularly if it is a highly drug-resistant strain or becomes an invasive infection.

“It is a skin commensal rather than gut flora,” said Elizabeth Jefferson, BS, PhD, CIC, infection preventionist and clinical epidemiologist at Scripps Memorial Hospital in La Jolla, CA. “Patients can remain colonized indefinitely, environmental surfaces can stay contaminated for months. It’s more difficult to identify in conventional labs, leading to misdiagnosis.”

From 912 isolates from around the world, about 65% were resistant to fluconazole, about 20% to amphotericin B, and 5% to echinocandins, she said. “[J]ust looking at the U.S. isolates, 33% are multidrug-resistant, and several have pan-resistance,” Jefferson said.

Not surprisingly, “a single confirmed case of C. auris from any body site is a cause for investigation and notification to public health authorities,” she told attendees at the 2021 virtual conference of the Association for Professionals in Infection Control and Epidemiology.

In 2020, there were 714 case of C. auris in the United States, 112 of which were in California. One of those was the first C. auris case in San Diego, Jefferson said.

“The patient arrived with healthcare history from abroad, so the case was imported, but still needed to be contained, because if unchecked, C. auris can spread like wildfire through a facility,” she said.

The male patient had a motorcycle accident in South Africa, experiencing injuries to the femur, tibia, and fibula. He was hospitalized in South Africa in two separate facilities before being transferred to San Diego 13 days after the accident and overseas treatment. The patient met criteria for carbapenemase-producing organism (CPO) screening because he had healthcare abroad, Jefferson explained.

“In this case, the patient was placed in preemptive contact precautions in a private room where gown and gloves were required and shared equipment was cleaned and disinfected,” she said. “The disinfectant was EPA (Environmental Protection Agency)-approved for killing C. diff.”

The preemptive precautions were wise; CPO screening was positive for OXA-48 carbapenemases. That triggered a test for C. auris, which has been detected in association with CPOs. C. auris was confirmed positive by a public health lab, then identified by the hospital microbiology lab.

“The C. auris case took place right at the beginning of the COVID-19 pandemic, so there were potential challenges,” Jefferson said. “The patient had a long length of stay — 45 days — so more time for transmission to occur. The patient had multiple trips to the OR (operating room), so more opportunities for contamination.”

Impressively, no transmission to other patients occurred despite a patient stay of about six weeks. Patients in adjacent rooms were tested for colonization, and the patient soon was moved to a remote corner room, she noted.

Infection control measures included “meticulous hand hygiene,” with alcohol-based rubs preferred over soap and water. “We used contact precautions requiring gown and gloves,” Jefferson said. “You need to use an EPA-approved disinfectant with label claims for killing C. auris or C. diff spores, and you have to adhere to the contact time.”

The patient room’s high-touch surfaces were cleaned and disinfected twice a day.

“The patient’s [six] surgeries were scheduled at the end of the day,” Jefferson said. “The OR was terminally cleaned and disinfected using both a chlorine-based disinfectant as well as UV (ultraviolet) disinfection. All rooms that the patient vacated were cleaned and disinfected twice. Processes were observed and audited.”

Another critical infection prevention measure was making sure the patient’s shared equipment was cleaned and disinfected. “This included the patient’s physical therapy equipment, the portable X-ray equipment, and so on,” she said. “As always, it is important to know who cleans what.”

Fortunately, the infecting strain of C. auris was not particularly resistant to fungal drugs, but still required extensive treatment. “So, although C. auris is commonly multidrug-resistant, levels of resistance can vary,” she said.

The patient was treated with micafungin, amphotericin B, and posaconazole. “On day 20, there was no fungus growth and on day 45, the patient was discharged home,” Jefferson said.

The patient was tested for C. auris colonization several months later and was found negative. His electronic medical record was flagged, indicating contact precautions for future admissions. No other cases of C. auris have been detected in the hospital a year following the case.

“This is a success story,” she said. “Surveillance and aggressive infection control measures are needed to prevent the transmission and spread of C. auris.”