SHEA 2023: C. auris Spreads Across Healthcare Continuum
First cluster of pediatric patients reported
The first cluster of pediatric patients with Candida auris and the ability of the emerging fungal pathogen to spread rapidly across the healthcare continuum were revealed in outbreak reports at the recent conference of the Society for Healthcare Epidemiology of America (SHEA).
A hospital outbreak in southern Nevada included both adult and pediatric patients, said Sophie Jones, PhD, MSc, BSc, an Epidemic Intelligence Service officer at the Centers for Disease Control and Prevention (CDC).
“In August 2021, the first case of C. auris in the southern Nevada region was identified in an adult patient at an acute care hospital,” she told SHEA attendees. “Case numbers increased rapidly. By late 2021, a regional response ramped up, that included screening to look for colonized patients.”
Including colonized patients, who can be asymptomatic yet spread the fungus, resulted in the identification of more than 250 cases identified across 16 healthcare facilities by early May 2021.
Between September 2021 and early May 2022, acute care hospital “one” identified 31 clinical infections in adult patients. This acute care hospital also had a pediatric unit, where three neonates under cardiac intensive care subsequently were infected by C. auris.
“Before this outbreak, pediatric cases of C. auris were extremely rare, with fewer than 10 reported in the United States,” Jones said. “But at acute care hospital one, we had three cases that represented the first cluster of pediatric patients identified in this country.”
The CDC and Nevada public health officials conducted a joint investigation to identify possible sources of transmission between adult to pediatric patients. Investigators went through medical charts, looking for patient risk factors and common exposures. They assessed infection prevention practices and did observations on units that housed adult and pediatric patients.
“Part of this was to perform auditing of hand hygiene compliance, use of personal protective equipment (PPE), and monitor environmental services cleaning and disinfection practices,” Jones said. “We also performed environmental sampling from high-touch surfaces and from mobile medical equipment around adult and pediatric units.”
Highly Vulnerable Babies
All three pediatric patients were younger than 6 months of age and all were born at hospital one. They were extremely vulnerable, having congenital heart disease, multiple invasive devices, and several cardiac surgeries.
“All three had invasive bloodstream infections (BSIs), which were the first [C. auris] BSIs identified in this country among pediatric patients,” Jones said. “Two of the pediatric patients subsequently developed fungal endocarditis, which is a hard-to-treat infection of the heart, and one patient died. C. auris was not specifically listed as the cause. All three pediatric patients had multiple risk factors for infection.”
The three pediatric patients had overlapping stays in the unit in neighboring rooms.
“During our infection prevention and control observations of healthcare workers and environmental services staff, we noted lapses that could have contributed to transmission of C. auris,” she said. “For example, some hand hygiene opportunities were missed among radiology technicians and environmental services staff.”
Moreover, during discharge room cleans, Jones and colleagues noted that clean-to-dirty workflow was not always followed, creating opportunities for contamination of the patient room, the environmental services cart, and cleaning supplies. In addition, gowns were not always worn tightly or doffed upon exit of the patient rooms.
“While these observations may not contribute to transmission individually, multiple lapses in infection prevention and control over time can result in transmission of C. auris between patients, either through direct contact during patient care activities or during contact with contaminated surfaces,” she told SHEA attendees.
There were very few common exposures between adult and pediatric patients, but informal interviews with staff revealed one that was compelling.
“Ultrasound technicians provided care to both adults and pediatric patients,” Jones said. “We learned that select pieces of mobile medical equipment, such as ultrasound machines, including echocardiograms, were also shared between them. Since the pediatric patients had potential for multiple echocardiograms since birth, due to their congenital heart disease, we considered that this could be a common exposure between the adult and pediatric patients.”
Indeed, investigators found that all the pediatric patients and two-thirds of the adult patients received an echocardiogram before testing positive for C. auris. Echocardiogram machines were wheeled between patient rooms.
You Use It, You Clean It
“When we talked to healthcare providers about cleaning and disinfection practices at the facility, they reported a who-uses-it-cleans-it policy,” Jones said. “But during discussions with healthcare personnel, it became clear that this information was not always commonly known nor did they consistently know which disinfectant product should be used.”
None of the environmental samples taken from the pediatric unit grew C. auris, but there were positive specimens in an adult room and on an adult patient lifting device. Of significance, the patient in the room was not known to have C. auris, and the lifting equipment was designated as clean. All isolates from the environment and patients were closely related in genomic sequencing, confirming this was a clonal outbreak that spread within the hospital.
“While we didn’t isolate C. auris from the [echocardiogram] equipment that was shared between the pediatric patients, we did isolate it from equipment shared among the adult patients,” Jones said. “[This] supported our observations about gaps in cleaning knowledge and practice with mobile medical equipment. We suspect that C. auris may have been transmitted to the pediatric patients from the adult patients through inadequately disinfected mobile medical equipment.”
Once in the pediatric unit, C. auris likely spread through transient colonization on the hands of healthcare workers via the initial infected patient or the environment. Among the recommendations for the hospital were to provide refresher training and conduct regular audits for hand hygiene compliance, proper use of PPE, and ensure environmental services workflow does not contribute to contamination.
The federal and state public health officials further recommended the hospital adopt a disinfection policy for mobile equipment that included:
• ensuring use of hospital-grade, Environmental Protection Agency-registered products with a claim against C. auris;
• assigning clear disinfection responsibility to staff members;
• training staff on how to perform adequate disinfection;
• implementation of a cleaning auditing and feedback system.
“We also recommended they strengthen their surveillance and screening, specifically by performing species identification of Candida from all body sites, by ensuring that point prevalence [studies] are promptly rolled out in units with suspected transmission, and by performing targeted admission screening from high-burden facilities,” Jones said. “Cases of Candida auris are continuing to increase and healthcare facilities can adopt our recommendations as part of their prevention package.”
A Formidable Fungus
As recently reported by the CDC, C. auris clinical infections increased 59% in 2020, then nearly doubled in 2021 with a 95% jump.1
This is the result of several factors, including pandemic chaos, increasing resistance to the few fungal drugs available, and an asymptomatic colonization state that is transmissible from the skin of these carriers. (See Hospital Infection Control & Prevention, May 2023.)
Given this latter point, public health officials in Maricopa County, AZ, conducted a massive contact tracing effort. The health department identified 2,373 C. auris contacts across 40 healthcare facilities, and, as part of this effort, did an educational infection prevention outreach to a total of 101 county healthcare settings.
All of this began with a community-acquired case in January 2022, and in the next few months C. auris was spreading within and among healthcare facilities, Serena Bailey, MPH, HAI Epidemiologist II with the Maricopa County Department of Public Health, reported at SHEA.
Over the next 10 months the outbreak continued, resulting in 184 clinical infections and colonizations with C. auris.
“We identified close contacts, limited further spread within the facility, determined and addressed intra- and interfacility transmission, and coordinated the response with the healthcare facilities as well as our state and federal partners,” Bailey said. “Each time we identified a clinical isolate, we began with educational infection prevention and control outreach to the affected facility. Many times, the infection preventionists were already aware of the case, but we reached out just to ensure that they were notified and provided our infection prevention guidance.”
“About 50% of the [2,373] contacts were discharged into the community, meaning they were either discharged home, left against medical advice, or were lost to follow-up,” Bailey said. “However, 42% of the contacts were discharged to other healthcare facilities, where we did follow up to facilitate that screening.”
Of those, they were able to set screening for 98% (972 patients) and 18% (155 patients) screened positive.
“That 18% of the contacts screened came back [positive] shows that, even though this required a lot of work, it paid off in identifying those colonized cases so that proper precautions could be put in place,” she said. “And of those 155 cases, 15 went on to develop a clinical infection.”
Overall, there were 29 clinical infections, including pulmonary infections, candidemia, and urinary tract and wound infections. “[Risk factors] included invasive medical devices, a history of other multidrug-resistant organisms, and immunosuppression,” Bailey said.
- Lyman M, Forsberg K, Sexton DJ, et al. Worsening spread of Candida auris in the United States, 2019 to 2021. Ann Intern Med 2023;176:489-495.
The first cluster of pediatric patients with Candida auris and the ability of the emerging fungal pathogen to spread rapidly across the healthcare continuum were revealed in outbreak reports at the recent conference of the Society for Healthcare Epidemiology of America.
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