Zygomycosis in a tertiary-care cancer center in the era of Aspergillus-active antifungal therapy: a case-control observational study of 27 recent cases.

BACKGROUND

Anecdotal evidence suggests a rise in zygomycosis in association with voriconazole (VRC) use in immunosuppressed patients.

METHODS

We performed prospective surveillance of patients with zygomycosis (group A; n = 27) and compared them with contemporaneous patients with invasive aspergillosis (group B; n = 54) and with matched contemporaneous high-risk patients without fungal infection (group C; n = 54). We also performed molecular typing and in vitro susceptibility testing of Zygomycetes isolates.

RESULTS

Nearly all patients with zygomycosis either had leukemia (n = 14) or were allogeneic bone marrow transplant recipients (n = 13). The Zygomycetes isolates (74% of which were of the genus Rhizopus) had different molecular fingerprinting profiles, and all were VRC resistant. In multivariate analysis of groups A and C, VRC prophylaxis (odds ratio [OR], 10.37 [95% confidence interval [CI]], 2.76-38.97]; P = .001), diabetes (OR, 8.39 [95% CI, 2.04-34.35]; P = .003), and malnutrition (OR, 3.70 [95% CI, 1.03-13.27]; P = .045) were found to be independent risk factors for zygomycosis. Between patients with zygomycosis (after excluding 6 patients with mixed mold infections) and patients with aspergillosis, VRC prophylaxis (OR, 20.30 [95% CI, 3.85-108.15]; P = .0001) and sinusitis (OR, 76.72 [95% CI, 6.48-908.15]; P = .001) were the only factors that favored the diagnosis of zygomycosis.

CONCLUSIONS

Zygomycosis should be considered in immunosuppressed patients who develop sinusitis while receiving VRC prophylaxis, especially those with diabetes and malnutrition.