Rapid Assessment and Containment of Candida auris Transmission in Postacute Care Settings-Orange County, California, 2019

Abstract

Background: Candida auris, a multidrug-resistant yeast, can spread rapidly in ventilator-capable skilled-nursing facilities (vSNFs) and long-term acute care hospitals (LTACHs). In 2018, a laboratory serving LTACHs in southern California began identifying species of Candida that were detected in urine specimens to enhance surveillance of C auris, and C auris was identified in February 2019 in a patient in an Orange County (OC), California, LTACH. Further investigation identified C auris at 3 associated facilities.

Objective: To assess the prevalence of C auris and infection prevention and control (IPC) practices in LTACHs and vSNFs in OC.

Design: Point prevalence surveys (PPSs), postdischarge testing for C auris detection, and assessments of IPC were done from March to October 2019.

Setting: All LTACHs (n = 3) and vSNFs (n = 14) serving adult patients in OC.

Participants: Current or recent patients in LTACHs and vSNFs in OC.

Intervention: In facilities where C auris was detected, PPSs were repeated every 2 weeks. Ongoing IPC support was provided.

Measurements: Antifungal susceptibility testing and whole-genome sequencing to assess isolate relatedness.

Results: Initial PPSs at 17 facilities identified 44 additional patients with C auris in 3 (100%) LTACHs and 6 (43%) vSNFs, with the first bloodstream infection reported in May 2019. By October 2019, a total of 182 patients with C auris were identified by serial PPSs and discharge testing. Of 81 isolates that were sequenced, all were clade III and highly related. Assessments of IPC identified gaps in hand hygiene, transmission-based precautions, and environmental cleaning. The outbreak was contained to 2 facilities by October 2019.

Limitation: Acute care hospitals were not assessed, and IPC improvements over time could not be rigorously evaluated.

Conclusion: Enhanced laboratory surveillance and prompt investigation with IPC support enabled swift identification and containment of C auris.

Primary funding source: Centers for Disease Control and Prevention.

Figure 1.

Prevalence of Candida auris and the total number of screening cases (new and known) among total facility census, identified on serial PPSs within all OC LTACHs and 6 vSNFs (A to F), by PPS number–OC, California, March to October 2019. LTACH = long-term acute care hospital; OC = Orange County; PPS = point prevalence survey; vSNF = ventilator-capable skilled-nursing facility. * First facility instances of 2 consecutive PPSs with no new positive detections.

Figure 2.

Whole-genome sequencing results of Candida auris isolates, OC, California, 2019. The scale bars shows pairwise SNPs. LTACH = long-term acute care hospital; OC = Orange County; SNP = single nucleotide polymorphism; vSNF = ventilator-capable skilled-nursing facility. A. Maximum parsimony tree showing the phylogenetic relationships among 133 Candida auris isolates representing all 4 clades constructed using 157 384 SNPs called against the C auris B11221 reference genome from South Africa (GenBank accession number PGLS00000000.1). All OC isolates clustered with clade III isolates and are represented by a blue circle. Evolutionary analyses were done in Molecular Evolutionary Genetics Analysis (MEGA X) (31). Visualizations were done using Microreact (33) (https://microreact.org/project/qo5WqozYyKCxDyezFXeEC5/fb86da3b). B. Phylogenetic sub tree clade III (Africa) representing genetic diversity among C auris isolates from different countries, including the United States (Maryland; Indiana; and OC, California). All 81 isolates from OC are clustered together and represented by a large blue triangle. C. Genetic variations among C auris isolates from 9 facilities in OC, California and the LTACHs or vSNFs where they were identified. All 81 OC investigation isolates clustered together. Visualizations were done using Microreact (33) (https://microreact.org/project/bQtzYm3JqYghYkFWsUMhMv).