Epidemiology of candidemia in Qatar: Performance of MALDI-TOF MS for identification of candida species, species distribution, outcome and susceptibility pattern

Abstract

Blood stream infections due to Candida species cause significant morbidity and mortality in health care settings. This surveillance analysis describes the epidemiology, trend in species distribution and outcomes of candidemia in patients at Hamad hospital, Doha, Qatar. From January 2004 to December 2010, a total of 187 patients with 201 episodes of candidemia were identified. C. albicans was the most common species isolated 33.8% (n=68), whereas non-albicans Candida species represented 66.2 % (n=133) of the episodes. The latter consisted of C. glabrata 18.9% (n=38), C. tropicalis 17.9% (n=36), C. parapsilosis 16.9% (n=34), C. orthopsilosis 4% (n=8) and C. dubliniensis 1.5% (n=3). Rare occurring cases of Pichia kudriavzevii , Meyerozyma guilliermondii, Clavispora lusitaniae, Wickerhamomyces anomalus and C. pararugosa (n=2 each) caused (4.9%) of infections. Uncommon yeast species such as C. intermedia, Yarrowia lipolytica, Kluyveromyces lactis , Lidnera fabianii, and Loddermyces elongisporus were found in single cases of candidemia (2.4%). The species distribution and outcome of candidemia showed a difference in crude mortality between patients infected with C. albicans (n=30, 45.5%) and non-albicans Candida species, e.g. C. parapsilosis candidemia was associated with the lowest mortality rate (40.6%), and patients with other non-albicans species had the highest mortality rate (68-71.4%). High mortality rates were observed among pediatric (<1year) and elderly patients (>60 years). All strains showed low MICs (≤ 1%) to isavuconazole. Overall reistance to voriconazole in vitro antifungal activity was 2.5%. Higher resistant rates were only observed for itraconazole (10.9%), C. glabata (n=38) was susceptible dose dependent to fluconazole. Except 0.5%, all isolates were susceptible to anidulafungin and 81.1% to caspofungin. Resistance to anidulafungin was detected in 1/8 (12.5%) isolates of C. orthopsilosis. According to new CLSI breakpoints, C. glabrata n=38 showed 100% resistance, and 37/68 (54.4%) of C. albicans were SDD to caspofungin. Identification by MALDI-MS was 100% in concordance with molecular identification.