Investigation of a nosocomial outbreak of fungemia caused by Candida pelliculosa (Pichia anomala) in a Korean tertiary care center

Abstract

Background: Candida pelliculosa is a rare pathogen of fungemia. There have been a few nosocomial outbreaks of C. pelliculosa fungemia in nurseries and pediatric intensive care units (ICU), hematologic units, and surgical ICU. We describe an epidemiologic outbreak investigation, including case findings of C. pelliculosa fungemia in South Korea. Methods: This outbreak investigation conducted in a 940-bed, tertiary referral center, Ulsan, South Korea and included active microbial surveillance and a case–control study. Results: A patient in the trauma intensive care unit (ICU) with multiple trauma developed C. pelliculosa fungemia, and 10 patients in the trauma ICU, medical ICU, and 2 general wards subsequently contracted C. pelliculosa fungemia during the next 24 days (November 16 and December 9, 2015). The 16s rRNA sequencing of 4 isolates showed that C. pelliculosa was verified with 99–100% similarity (GenBank accession number: KF317892.1), and these isolates were identical in the randomly amplified polymorphic DNA (RAPD) assay. A case–control study showed that medical staff and staying in the interventional radiology procedure room were risk factor for development of C. pelliculosa fungemia. After intervention including strict hand washing, disinfecting medical equipment, and contact precautions, there have been no new C. pelliculosa infections since December 10, 2015. Conclusions: This is the first report of a nosocomial outbreak involving 11 patients in 2 ICUs and 2 general wards caused by C. pelliculosa in South Korea. Infection control measures are important for decreasing transmission of C. pelliculosa in the hospital. Keywords: Candida pelliculosa, Fungemia, Outbreak