Five-Year National Surveillance of Invasive Candidiasis: Species Distribution and Azole Susceptibility from the China Hospital Invasive Fungal Surveillance Net (CHIF-NET) Study

Abstract

Data on the epidemiology of invasive candidiasis (IC) and the antifungal susceptibility of <i>Candida</i> isolates in China are still limited. Here we report on surveillance for IC from the China Hospital Invasive Fungal Surveillance Net (CHIF-NET) study. Sixty-five tertiary hospitals collected 8,829 <i>Candida</i> isolates from 1 August 2009 to 31 July 2014. Matrix-assisted laser desorption ionization-time of flight mass spectrometry supplemented by ribosomal DNA sequencing was used to define the species, and the fluconazole and voriconazole susceptibilities were determined by the Clinical and Laboratory Standards Institute disk diffusion method. A total of 32 <i>Candida</i> species were identified. <i>Candida albicans</i> was the most common species (44.9%), followed by the <i>C. parapsilosis</i> complex (20.0%), <i>C. tropicalis</i> (17.2%), and the <i>C. glabrata</i> complex (10.8%), with other species comprising <3% of isolates. However, in candidemia, the proportion of cases caused by <i>C. albicans</i> was only 32.3%. <i>C. albicans</i> and <i>C. parapsilosis</i> complex isolates were susceptible to fluconazole and voriconazole (<6% resistance), while fluconazole and azole cross-resistance rates were high in <i>C. tropicalis</i> (13.3% and 12.9%, respectively), <i>C. glabrata</i> complex (18.7% and 14%, respectively), and uncommon <i>Candida</i> species (44.1% and 10.3%, respectively) isolates. Moreover, from years 1 to 5 of the study, there was a significant increase in the rates of resistance to fluconazole among <i>C. glabrata</i> complex isolates (12.2% to 24.0%) and to both fluconazole (5.7% to 21.0%) and voriconazole (5.7% to 21.4%) among <i>C. tropicalis</i> isolates (<i>P</i> < 0.01 for all comparisons). Geographic variations in the causative species and susceptibilities were noted. Our findings indicate that antifungal resistance has become noteworthy in China, and enhanced surveillance is warranted.