Local public health response to first Candida auris outbreak spanning 28 healthcare facilities—Maricopa County, Arizona, April 2022–February 2023

Abstract Objective: Describe the first healthcare-associated outbreak of Candida auris in Maricopa County, Arizona. Also, outline the Maricopa County Department of Public Health (MCDPH) response activities to halt transmission and identify affected healthcare facilities (HCFs) and contacts colonized with C. auris . Methods: At HCFs with confirmed C. auris cases (i.e., exposed HCFs), MCDPH provided virtual infection control assessment and response activities, including contact investigations among hospitalized patients and point prevalence surveys (PPSs) to identify ongoing transmission. Confirmed C. auris cases included C. auris detected by cultures or polymerase chain reaction (PCR) in a hospitalized patient. Clinical cases had C. auris from cultures obtained during routine care in a hospitalized patient. Colonized cases included C. auris detected by PCR obtained from hospitalized patients for screening purposes. Results: On April 21, 2022, the first clinical case was identified, resulting in an outbreak with C. auris screening at 28 exposed HCFs. In total, 39 clinical C. auris cases were reported. Among 1,994 contacts identified, 899 (45.0%) were screened, 8 (0.4%) declined screening, and 1,087 (54.5%) were ineligible for screening (i.e., no longer hospitalized in Maricopa County). Among screened patients, 158 (17.6%) were colonized with C. auris ; 15 (9.5%) colonized contacts later acquired clinical infections. This outbreak concluded on February 23, 2023, after 2 consecutive PPSs yielded no C. auris detection at exposed HCFs. Conclusions: The first C. auris outbreak in Maricopa County highlights the coordinated efforts between HCFs, laboratories, and public health to identify exposed HCFs, screen contacts, and halt C. auris transmission.