Surveillance for invasive candidiasis in China (CHIF-NET 2018-2021): rising antifungal resistance observed in a nationwide longitudinal study

ABSTRACT Invasive candidiasis (IC) is a severe infection primarily affecting immunocompromised patients and is associated with high mortality and substantial hospital costs. Accurate regional data on epidemiology and antifungal resistance of IC are crucial for effective clinical management. The China Hospital Invasive Fungal Surveillance Net (CHIF-NET) study is a laboratory-based multicenter study initiated in August 2009. This report presented updated data from August 2017 to December 2021, involving 76 hospitals across 28 provincial regions in China, and included a 12-year longitudinal analysis. Isolates from patients with IC were assigned to species level by matrix-assisted laser desorption ionization-time of flight mass spectrometry and internal transcribed spacer rDNA sequencing. Susceptibility testing was performed for nine antifungal agents using the broth microdilution method. A total of 11,679 Candida isolates were collected. Candida albicans was the most common Candida species (46.0%), followed by Candida tropicalis (17.6%), Candida parapsilosis sensu stricto (15.6%), and Candida glabrata sensu stricto (11.2%). Antifungal resistance rates showed notable variations among different Candida species, with the highest azole resistance observed in C. tropicalis isolates causing candidemia (42.5% to fluconazole and 38.9% to voriconazole). Cross- and multi-drug resistance to azoles and echinocandins was observed in all predominant Candida species. The species distribution of major Candida pathogens causing IC remained stable in China, while antifungal resistance increased, especially among non- albicans Candida species. Enhanced surveillance, accurate species identification, and strengthened antifungal stewardship are needed to address the growing challenge of antifungal resistance.