The sensitivity for detection of resistance in primary cultures with the VIPcheck plate depends on the number of A. fumigatus colonies that are tested, as clinical cultures may contain both mixed azole-susceptible and azole-resistant isolates during an infection [20]. We suspect that A. fumigatus isolated in the first tracheal aspirate was already a mixed culture but was missed in initial fungal cultures due to abundance of azole-susceptible A. fumigatus spores. Molecular detection could have given a suggestion to the presence of a mixed culture [21] but PCR could not be performed due to absence of material. The TR34/L98H had a phenotype with high itraconazole MIC (>16 mg/L) and low voriconazole MIC (2 mg/L), similar to strains which have been described only recently in the Netherlands [22].