INTERNATIONAL SURVEILLANCE OF BLOOD-STREAM INFECTIONS DUE TO CANDIDA SPECIES - FREQUENCY OF OCCURRENCE AND ANTIFUNGAL SUSCEPTIBILITIES OF ISOLATES COLLECTED IN 1997 IN THE UNITED-STATES, CANADA, AND SOUTH-AMERICA FOR THE SENTRY PROGRAM

An international program of surveillance of bloodstream infections (BS Is) in the United States, Canada, and South America between January an d December 1997 detected 306 episodes of candidemia in 34 medical cent ers (22 in the United States, 6 in Canada, and 6 in South America). Ei ghty percent of the BSIs were nosocomial and 50% occurred in patients hospitalized in an intensive care unit. Overall, 53.3% of the BSIs wer e due to Candida albicans, 15.7% were due to C. parapsilosis, 15.0% we re due to C. glabrata, 7.8% were due to C. tropicalis, 2.0% were due t o C. krusei, 0.7% were due to C. guilliermondii, and 5.8% were due to Candida spp, However, the distribution of species varied markedly by c ountry. In the United States, 43.8% of BSIs were due to non-C. albican s species. C. glabrata was the most common non-C. albicans species in the United States. The proportion of non-C. albicans BSIs was slightly higher in Canada (47.5%), where C. parapsilosis, not C. glabrata, was the most common non-C, albicans species. C. albicans accounted for 40 .5% of all BSIs in South America, followed by C. parapsilosis (38.1%) and C, tropicalis (11.9%). Only one BSI due to C. glabrata was observe d in South American hospitals. Among the different species of Candida, resistance to fluconazole (MIC, greater than or equal to 64 mu g/ml) and itraconazole (MIC, greater than or equal to 1.0 mu g/ml) was obser ved with C. glabrata and C. krusei and was observed more rarely among other species. Isolates of C. albicans, C. parapsilosis, C. tropicalis , and C. guilliermondii were all highly susceptible to both fluconazol e (99.4 to 100% susceptibility) and itraconazole (95.8 to 100% suscept ibility). In contrast, 8.7% of C. glabrata isolates (MIC at which 90% of isolates are inhibited [MIC90], 32 mu g/ml) and 100% of C. krusei i solates were resistant to fluconazole, and 36.9% of C. glabrata isolat es MIC90, 2.0 mu g/ml) and 66.6% of C, krusei isolates were resistant to itraconazole. Within each species there were no geographic differen ces in susceptibility to fluconazole or itraconazole.