Update 2016–2018 of the Nationwide Danish Fungaemia Surveillance Study: Epidemiologic Changes in a 15-Year Perspective

As part of a national surveillance programme initiated in 2004, fungal blood isolates from 2016–2018 underwent species identification and EUCAST susceptibility testing. The epidemiology was described and compared to data from previous years. In 2016–2018, 1454 unique isolates were included. The fungaemia rate was 8.13/100,000 inhabitants compared to 8.64, 9.03, and 8.38 in 2004–2007, 2008–2011, and 2012–2015, respectively. Half of the cases (52.8%) involved patients 60–79 years old and the incidence was highest in males ≥70 years old. <i>Candida albicans</i> accounted for 42.1% of all isolates and <i>Candida glabrata</i> for 32.1%. <i>C. albicans</i> was more frequent in males (<i>p</i> = 0.03) and <i>C. glabrata</i> in females (<i>p</i> = 0.03). During the four periods, the proportion of <i>C. albicans</i> decreased (<i>p</i> < 0.001), and <i>C. glabrata</i> increased (<i>p</i> < 0.001). Consequently, fluconazole susceptibility gradually decreased from 68.5% to 59.0% (<i>p</i> < 0.001). Acquired fluconazole resistance was found in 4.6% <i>Candida</i> isolates in 2016–2018. Acquired echinocandin resistance increased during the four periods 0.0%, 0.6%, 1.7% to 1.5% (<i>p</i> < 0.0001). Sixteen echinocandin-resistant isolates from 2016–2018 harboured well-known <i>FKS</i> resistance-mutations and one echinocandin-resistant <i>C. albicans</i> had an <i>FKS</i> mutation outside the hotspot (P1354P/S) of unknown importance. In <i>C. glabrata</i> specifically, echinocandin resistance was detected in 12/460 (2.6%) in 2016–2018 whereas multidrug-class resistance was rare (1/460 isolates (0.2%)). Since the increase in incidence during 2004–2011, the incidence has stabilised. In contrast, the species distribution has changed gradually over the 15 years, with increased <i>C. glabrata</i> at the expense of <i>C. albicans</i>. The consequent decreased fluconazole susceptibility and the emergence of acquired echinocandin resistance complicates the management of fungaemia and calls for antifungal drug development.