Multiple-Triazole–Resistant Aspergillosis

To the Editor: The use of voriconazole has become common for the management of invasive aspergillosis. However, therapy with voriconazole still sometimes fails, more often because of unresponsive underlying disease than because of resistance of the fungus. Since the first description of itraconazole resistance in Aspergillus fumigatus, 1 three amino acid substitutions in the 14α-sterol demethylase cyp51A gene, which is the target site for azole drugs, have been described.2 Our laboratory receives fungal isolates for identification and susceptibility testing from throughout the Netherlands. Since 2002, using Clinical and Laboratory Standards Institute methodology, we have observed an increase in the number of . . .