Emerging issues, challenges, and changing epidemiology of fungal disease outbreaks

Several recent high-profile outbreaks have drawn attention to invasive fungal infections (IFIs) as an increasingly important public health problem. IFI outbreaks are caused by many different fungal pathogens and are associated with numerous settings and sources. In the community, IFI outbreaks often occur among persons without predisposing medical conditions and are frequently precipitated by environmental disruption. Healthcare-associated IFI outbreaks have been linked to sub-optimal hospital environmental conditions, transmission via healthcare workers’ hands, contaminated medical products, and transplantation of infected organs. Outbreak investigations provide important insights into the epidemiology of IFIs, uncover risk factors for infection, and identify opportunities for preventing similar events in the future. Well-recognized challenges with IFI outbreak recognition, response, and prevention include the need for improved rapid diagnostic methods, the lack of routine surveillance for most IFIs, adherence to infection control practices, and healthcare provider awareness. In addition, recent IFI outbreak investigations have revealed several emerging issues, including: new populations at risk because of travel or relocation, occupation, or immunosuppression; fungal pathogens appearing in geographic areas in which they have not been previously recognized; and contaminated compounded medications. This review highlights notable IFI outbreaks in the past decade, with an emphasis on these emerging challenges in the United States.