Nosocomial fungal infections – an emerging threat to healthcare settings

Nosocomial fungal infections pose an increasing threat to healthcare settings, presenting significant challenges to patient care and infection control practices. These infections are mostly opportunistic in nature, affecting patients with compromised immune systems, prolonged hospital stays, and exposure to invasive medical procedures, thereby contributing to significant morbidity and mortality. The epidemiology of nosocomial fungal infections has been further complicated by the COVID-19 pandemic, with a notable increase in the incidence of fungal infections among hospitalized patients, including COVID-19–associated candidiasis and COVID-19–associated pulmonary aspergillosis globally.

Among the concerning pathogens, Candida auris, a multidrug-resistant yeast species, is rapidly spreading worldwide, leading to nosocomial outbreaks. Notably, patients can remain colonized by C. auris for a prolonged period, facilitating environmental shedding and persistence on a wide range of surfaces. Given its high transmissibility, proactive infection control measures, including active surveillance cultures for high-risk patients, prompt isolation of confirmed cases, comprehensive contact tracing to identify secondary cases, and strict enforcement of hand hygiene and environmental disinfection protocols, are of paramount importance.

Other unusual fungal pathogens have also posed threats to healthcare settings. In the United States, Exserohilum rostratum, a plant pathogen that rarely causes human disease, was associated with contaminated intrathecal methylprednisolone injections, resulting in over 700 infected cases. In Hong Kong, nosocomial outbreaks of intestinal and pulmonary/cutaneous zygomycosis (Rhizopus microspores) caused by contaminated drug tablets, allopurinol, and contaminated linens were reported. Therefore, clinical vigilance is necessary to detect patients with unusual nosocomial fungal infections and ensure early recognition and control of outbreaks.