Broader Screening Methods Help Prevent Spread of Dangerous Fungal Pathogen in Hospitals

A new study published today in the American Journal of Infection Control (AJIC) describes the outcome of a shift in hospital screening protocols for Candida auris (C. auris), a dangerous and often drug-resistant fungal pathogen that spreads easily in hospital environments.

A comparison of screening results and patient outcomes before and after the protocol shift at Mount Sinai Brooklyn demonstrated the value of broader screening of high-risk patients. As a result of expanded screening, more cases were caught early, enabling infection prevention and control teams to isolate them before they could infect other patients or contaminate shared hospital equipment.

C. auris is an emerging fungal pathogen, first identified in 2009 and now found globally. While the U.S. Centers for Disease Control and Prevention (CDC) and other public health agencies recommend screening patients admitted to the hospital to identify anyone colonized by the pathogen, many different screening approaches exist. Broader screening catches more cases, but it requires more resources and can be impractical in healthcare facilities where patients cannot easily be isolated while results are generated.

The study was triggered by the case of a single patient. The patient was moved from a skilled nursing facility to the Mount Sinai Brooklyn hospital in 2022; after more than two months at the hospital, the patient was diagnosed with a C. auris infection. The patient had not been screened for C. auris upon admission because the hospital’s screening protocols at the time classified the patient as low risk. After diagnosis, the hospital conducted a full outbreak investigation, testing 118 people who were directly exposed to the patient or shared equipment with the patient. The investigation identified eight additional patients who tested positive for C. auris.

Given the time and resources required for the investigation, the hospital’s Infection Prevention and Control Department adjusted its recommended C. auris screening protocols for new patients, expanding them to include all admissions from skilled nursing facilities or patients who had been in such a facility within the past month. After using the new protocols for one year, they compared outcomes for that year to the nine-month period prior to the screening change.

The study spanned 591 patients who were screened for C. auris; that includes 34 patients with the previous screening approach and 557 patients screened under the expanded protocol. The positivity rate increased from 1.8% to 2.4%, indicating that more cases were being detected with the broader screening approach. More specifically, the previous criteria would have flagged 53 patients as high-risk, and nine of them would have tested positive for C. auris. The expanded protocol added 538 more patients, five of whom tested positive but would not have been identified through the old screening protocol. Ultimately, the new protocol identified eight cases that would have been missed, representing a significant threat to other patients and the hospital environment. Test results were returned within three days, allowing the team to identify cases quickly and implement appropriate isolation, contact, and disinfection precautions to prevent outbreaks.

“Early identification of patients colonized with C. auris allows us to protect other patients and helps to prevent the spread of the pathogen to the hospital environment and shared equipment,” said Scott Lorin, MD, Mount Sinai Brooklyn president and an author of the study. “Notably, we saw no spread of this infection from the eight patients identified by the expanded screening protocols who would have been missed by our prior protocol. When you consider how many other people they came into contact with during their hospital stays, that’s a lot of patients kept safer by the implementation of broader screening. This expanded screening protocol has allowed us to detect Candida auris cases earlier, helping us prevent potential hospital outbreaks.”