Investigation of a healthcare-associated Candida tropicalis candidiasis cluster in a haematology unit and a systematic review of nosocomial outbreaks.

Abstract

Non-albicans Candida spp. are an emerging cause of hospital-acquired bloodstream infections, associated with high mortality due to the challenges in diagnosis and delayed treatment. We aimed to investigate a cluster of healthcare-associated invasive candidiasis caused by Ctropicalis and review the literature of healthcare-associated outbreaks or clusters caused by Ctropicalis. An investigation was performed to determine clinical presentation, treatment outcomes and the factors contributing to Ctropicalis candidemia occurrence. We searched the Medline database via PubMed and Ovid using the keywords of "Candida tropicalis" combined with "outbreak" or "clustering" or "clusters," and we limited the search to studies conducted from January 1989 to January 2019. We report two related cases of Ctropicalis candidemia among patients with AML following a period of neutropenia, who had erythematous skin rash as a first manifesting sign of candidiasis. Ctropicalis was isolated from blood and skin cultures of both patients, which were identical by pulsed-field gel electrophoresis typing. Our systematic review of outbreaks caused by Ctropicalis suggests that (a) most reported outbreaks have occurred in neonatal and adult ICUs; (b) patients who receive total parenteral therapy, antibiotics and those who have indwelling catheters and recent surgery are at high risk of infection; and (c) environmental and healthcare personnel surveillance suggest that cross-contamination is a major risk factor. Control of nosocomial outbreaks caused by Ctropicalis should include better infection control measures, education of healthcare professionals especially working in adult and neonatal intensive care and haematology units.