Two recent studies indicate that patients with azole-resistant invasive aspergillosis have a higher mortality that those with azole-susceptible infection. The first study [Clin Infect Dis 2019;68:1463–1471] was a retrospective cohort study in three University Medical Centers in the Netherlands. A total of 196 culture-positive patients with invasive aspergillosis were identified. The resistance phenotype of Aspergillus fumigatus cultures was screened using VIPCheck™. A voriconazole-resistant infection was observed in 37 (19%) patients. Most (79%) patients were treated with voriconazole and switched to other treatment regimens when resistance was detected. The underlying diseases of patients varied with hematological malignancy being the most frequent underlying condition. Compared with voriconazole-susceptible cases, voriconazole resistance was associated with an increase in overall mortality of 21% on day 42 (49% vs 28%; P = .017) and 25% on day 90 (62% vs 37%; P = .0038). The study also indicated that early detection of resistance was important to reduce mortality, underscoring the need for rapid tests that detect the presence of resistance.
The second study focused on patients with hematological malignancy involving the three Dutch University Medical Centers and the University Hospital Leuven in Belgium [J Antimicrob Chemother. 2019 Jun 24. pii: dkz258. doi: 10.1093/jac/dkz258. [Epub ahead of print]. Following a similar approach to the abovementioned study 129 culture-positive patients with invasive aspergillosis were identified, of which 26 had a voriconazole-resistant infection. In addition to a high frequency of azole resistance, again a difference in patient survival was found in non-ICU patients of 23% at 12 weeks (54.4% versus 30.7%; P = 0.035).
Both studies show that azole resistance reduces survival in patients with azole-resistant invasive aspergillosis compared to azole-susceptible infection and underscore the importance of resistance detection in regions where azole resistance is found.