The Changing Epidemiology of Invasive Aspergillosis in the Non-Traditional Host: Risk Factors and Outcomes

Background: Invasive fungal infections due to Aspergillus spp.are common in 'high-risk' immunocompromised patients.Recently, invasive aspergillosis (IA) in the 'low-risk' or 'non-traditional' host has been increasingly recognized.Unfortunately, risk factors and diagnostic modalities for this infection are poorly described.This study's goal is to further characterize IA in the population classically described as 'low-risk' and infrequently studied.Methods: A retrospective cohort of patients with proven or probable IA (excluding those with neutropenia or hematologic malignancy) was evaluated.Results: Thirty-six patients with either proven (23) or probable (13) IA met inclusion criteria.Mean age was 54.6 years.The most common risk factors identified in patients with IA were steroid use (69%), ICU stay (56%), immunosuppressive agents (39%), solid organ transplant (33%), diabetes (28%) and mechanical ventilation (28%).The most common sites of infection were lungs (67%) and sinuses (19%).A. fumigatus was the most prevalent spp.isolated (63%), followed by A. niger (16%).Additionally, 17 patients had bacterial coinfections.Voriconazole was the first-line antifungal used in 23 patients, followed by combination antifungal therapy in eight patients.Clinical success was noted in 72% of patients with a 25% cumulative mortality 90 days after diagnosis.Conclusions: This study describes IA in a population infrequently studied and considered to be at low risk when compared to the neutropenic population of patients.Awareness of risk factors in this 'non-traditional' host, improved diagnostic techniques, and earlier initiation of appropriate antifungal therapy should improve overall survival and response to therapy.Larger, multicenter epidemiologic studies in similar populations are warranted to improve the understanding of this underestimated infection.