Candida auris screening practices at healthcare facilities in the United States: An Emerging Infections Network survey

Abstract

We surveyed members of the Emerging Infections Network about Candida auris screening practices at US healthcare facilities. Only 37% of respondents reported conducting screening; among these, 75% reported detection of at least 1 C. auris case in the last year. Increased screening could improve C. auris detection and prevent spread.

Candida auris is an emerging fungal pathogen that colonizes the skin, particularly of patients who are chronically ill, have indwelling medical devices, or have frequent or prolonged healthcare exposures. ¹ It contaminates healthcare surfaces and is not killed using certain commonly used healthcare disinfectants, making it prone to spreading in healthcare facilities. ² Many products which are solely dependent on quaternary ammonia compounds (QACs) are not effective against C. auris. ³ Approximately 5%–10% of patients with C. auris skin colonization develop invasive disease, which is associated with high mortality rates ranging from 30% to 70%. ⁴

Identifying patients colonized with C. auris through screening can help prevent spread in healthcare facilities by prompting implementation of appropriate infection prevention and control measures. CDC recommends C. auris colonization screening based on local epidemiological conditions, patient characteristics, and facility-level risk factors (https://www.cdc.gov/hai/mdro-guides/prevention-strategy.html). Such screening might help facilities in higher burden areas to mitigate transmission and those in lower burden areas to detect new introductions before spread begins (https://www.cdc.gov/hai/mdro-guides/containment-strategy.html). Screening practices at US healthcare facilities, including information on how practices vary based on local C. auris prevalence and how frequently screening detects new cases, are not well described. Therefore, we surveyed a US-based network of infectious disease practitioners about screening practices in their healthcare facilities.

Methods

The Infectious Disease Society of America (IDSA) Emerging Infections Network (EIN) is a sentinel network of infectious disease physicians and other infectious disease specialists. ⁵ In August 2022, a link to a survey about C. auris screening practices was sent via the EIN listserv to ∼3,000 member subscribers on 3 separate occasions ∼1 week apart.

The survey included questions about whether screening was performed in the respondent’s facility, whether patients were screened on admission or once they were already in the facility, laboratory methods used for screening, numbers of screening tests conducted and C. auris cases detected in the prior year, and their facility’s location (city and state). Respondents could also report challenges or other observations about screening using a free-text response. We grouped responses by region within states (eg, southern California), and used Fisher exact tests to compare responses from regions where C. auris is frequently identified or endemic (tier 3 or 4) or not frequently identified (tier 2), as defined in the CDC’s multidrug-resistant organism containment guidance (https://www.cdc.gov/hai/mdro-guides/containment-strategy.html). The location of survey responses in tier 3 or 4 or tier 2 regions was based on the investigator’s informal assessment using information about C. auris case counts, transmission, and outbreaks in the year before the survey was launched.

Results

We received 253 responses, 119 (47%) from tier 3 or 4 areas and 134 (53%) from tier 2 areas. Responses were from 37 states and the District of Columbia, most frequently California (n = 87), New York (n = 17), Illinois (n = 12), and Florida (n = 11), with <10 responses from each of the remaining states.

Overall, 37% of respondents reported that C. auris screening was conducted at their facility (Table 1). More respondents from facilities in tier 3 or 4 areas reported screening than those from tier 2 areas (59% vs 17%; P < .01). Among respondents from facilities that conducted screening, 77% reported screening on admission and 51% reported screening patients already in the facility (eg, in response to cases or as part of point prevalence surveys). Respondents from tier 3 or 4 facilities more frequently reported screening patients on admission compared with tier 2 facilities (84% vs 55%; P = .01), whereas screening patients already in the facility was similar in tier 3 or 4 facilities and tier 2 facilities (49% vs 59%; P = .54). In-house laboratory testing was more commonly available in tier 3 or 4 facilities versus tier 2 facilities (68% vs 29%; P < .01), whereas respondents from tier 2 facilities more frequently reported sending screening specimens to external laboratories (71% vs 32%; P < .01). Among facilities that employed in-house tests, 67% used culture-based methods, 31% used PCR, and 2% employed other methods.

Table 1. Candida auris Screening Practices Among Emerging Infections Network (EIN) Survey Respondents—United States, 2022

^a Results are stratified by whether the respondents were located in a region where C. auris is frequently identified (tier 3 or 4) or not frequently identified (tier 2), based on an informal CDC assessment using existing multidrug-resistant organism containment guidance (https://www.cdc.gov/hai/containment/guidelines.html).

^b Selected healthcare facilities include influential healthcare facilities or those experiencing outbreaks.

^c Certain units within healthcare facilities, such as intensive care units.

Among the 68 respondents who reported screening and had complete responses for numbers of patients screened and positive cases detected in the last year, 75% reported having identified ≥1 case in the previous year (tier 3 or 4 facilities, 87%; tier 2 facilities, 38%; P < .01) and 37% reported having identified >5 cases (tier 3 or 4 facilities, 40%; tier 2 facilities, 25%; P = .41) (Table 2). Among 44 respondents who reported screening >25 patients in the last year, 91% had identified ≥1 case in the previous year (tier 3 or 4 facilities, 92%; tier 2 facilities, 80%; P = .94). Among the same group, 55% identified >5 cases in the previous year (tier 3 or 4 facilities, 51%; tier 2 facilities, 80%; P = .46).

Table 2. Colonization Cases Detected by Numbers of Patients Screened for Candida auris colonization in the last year, among survey respondents who reported screening — United States, 2022

^a Results are stratified by whether the respondents were located in a region where C. auris is frequently identified (tier 3 or 4) or not frequently identified (tier 2), based on an informal CDC assessment using existing multidrug-resistant organism containment guidance (https://www.cdc.gov/hai/containment/guidelines.html).

Limited laboratory capacity and long testing turnaround times were the challenges were reported by 6 respondents. Two respondents described limited resources and staff time to systematically identify which patients should be screened, such as admissions from high-risk facilities.

Discussion

Reported rates of C. auris screening at facilities were low: only 17% of EIN member respondents from tier 2 facilities and 60% from tier 3 or 4 facilities reporting any screening during the previous year. Admission screening was less frequently reported at tier 2 facilities, which is concerning because admission screening in areas where C. auris is not yet common has the potential to detect new introductions and guide the implementation of prevention measures before spread begins (https://www.cdc.gov/hai/mdro-guides/prevention-strategy.html). Additionally, results showed room for expanding screening among facilities in tier 3 or 4 areas where C. auris is prevalent. Preventive and responsive point prevalence surveys in facilities in these areas could help detect transmission and guide containment measures to limit further spread. ^6,7 Altogether, these findings suggest opportunities to increase adoption of C. auris screening across US facilities, which might aid detection and prevent spread within and among facilities.

The challenges that respondents identified might prevent wider adoption of C. auris screening. The long turnaround time of culture-based methods compared to PCR may limit the feasibility of screening programs among facilities. ^8,9 The CDC Antimicrobial Resistance Laboratory Network is a network of public health laboratories that provides free PCR-based colonization screening testing for healthcare facilities and health departments (https://www.cdc.gov/drugresistance/ar-lab-networks/domestic.html). Additionally, greater availability of PCR-based in-house laboratory testing might increase the adoption of C. auris screening by facilities. Limited staff availability and time to identify which patients should be screened and to conduct screening could also be a barrier to the adoption of screening programs. ¹⁰ Existing prevention guidance can help prioritize which patients should be screened, and increasing staff capacity for multidrug-resistance organism surveillance and adding tools like screening prompts in the admission electronic medical record may facilitate implementation. ¹¹

The survey was distributed to the entire EIN listserv rather than focusing on providers specifically involved with C. auris screening. Nevertheless, it is possible that primarily members who had experience with C. auris responded, potentially biasing our estimates of the proportion of facilities that conduct screening. Because survey responses were anonymized, we could not assess whether some facilities had duplicated responses from multiple EIN members. However, duplication appeared uncommon as responses came from 37 states and Washington, DC, and from diverse locations within states.

Overall, these results provide insight into screening practices and challenges for US healthcare facilities. Increased screening at tier 3 or 4 facilities and targeted admission screening in tier 2 facilities could enable better C. auris detection and help prevent the spread of this rapidly emerging pathogen.