Invasive yeast infections in the intensive care unit of a tertiary care centre in South India

INTRODUCTION: The incidence of invasive mycoses has increased enormously due to the rising population of critically ill patients. Emergence of rare yeasts with variable sensitivity patterns has underlined the need to monitor laboratory data for the emergence of resistance. AIMS: To determine the prevalence and susceptibility patterns of invasive mycoses and analyse the causative risk factors in the Intensive Care Unit (ICU) of a tertiary care centre in South India. MATERIALS AND METHODS: This is a retrospective, observational study performed on invasive Candida species isolated from patients admitted to the ICU. All the blood and cerebrospinal fluid (CSF) samples from ICU patients, over a period of one year, were included in the study. Preliminary identification of the isolates was done by VITEK. Genotypic identification of each isolate was done using colony polymerase chain reaction-restriction fragment length polymorphism and gene sequencing. Susceptibility pattern was ascertained by broth microdilution method according to the Clinical and Laboratory Standards Institute guidelines in document M27-A3. Relevant clinical details of the patients were collected from the records for the analysis of risk factors and outcome. RESULTS: The present study was done on 4629 blood and 341 CSF specimens, which were sent to the central clinical microbiology laboratory for diagnosis, between November 2013 and October 2014. A total of 49 Candida strains were isolated during the study period, with a prevalence of candidaemia in our ICU to be 1.05%. Candida tropicalis 19 (35.8%) was found to be the predominant species, followed by Candida albicans, Candida parapsilosis, Candida auris, Candida glabrata, Candida duobushaemulonii and Candida krusei. All the Candida species were found to be sensitive to Anidulafungin and Micafungin. Candida isolates were sensitive to Fluconazole - 39 (80.4%), Voriconazole - 49 (100%), Amphotericin B - 27 (54.7%) and Caspofungin - 48 (96.3%). Risk factor analysis revealed intravenous catheterisation as the major predisposing factor, followed by prior therapy with broad-spectrum antibiotics, mechanical ventilation, urinary catheterisation, diabetes mellitus and steroid therapy. Four isolates of Cryptococcus neoformans were also isolated from the blood samples. Three (0.8%) cases of fungal meningitis were diagnosed from 341 CSF samples, with C. tropicalis, C. neoformans and Cryptococcus gattii as causatives. CONCLUSION: It is of paramount importance to promptly identify and precisely determine the susceptibility of these agents, to combat this medical battle.