Many uncommon Candida species that cause bloodstream infections (BSIs) are not well-characterized. We investigated the epidemiology, antifungal use, susceptibility patterns, and factors associated with all-cause death among cancer patients in whom uncommon Candida spp. BSIs were diagnosed at a cancer treatment center during January 1998–September 2013. Of 1,395 Candida bloodstream isolates, 79 from 68 patients were uncommon Candida spp. The incidence density of uncommon Candida spp. BSIs and their proportion to all candidemia episodes substantively increased during the study period, and the rise was associated with increasing use of echinocandin antifungal drugs. Thirty-seven patients had breakthrough infections during therapy or prophylaxis with various systemic antifungal drugs for >7 consecutive days; 21 were receiving an echinocandin. C. kefyr (82%), and C. lusitaniae (21%) isolates frequently showed caspofungin MICs above the epidemiologic cutoff values. These findings support the need for institutional surveillance for uncommon Candida spp. among cancer patients.
Keywords: C. dublinensis; C. famata; C. guilliermondii; C. kefyr; C. lusitaniae; Candida; Houston; Texas; USA; antimicrobial drugs; cancer; candidemia; caspofungin; echinocandins; fungi; non-albicans.