Invasive fungal disease in PICU: epidemiology and risk factors

Candida and Aspergillus spp. are the most common agents responsible for invasive fungal infections (IFI) in children. They are associated with a high mortality and morbidity rate as well as high health care costs. Their incidence has dramatically increased within the past two decades [1-3]. In children, invasive Candida infection (ICI) is five times more frequent than invasive Aspergillus infection (IAI). Candida spp. is the third most common agent implicated in healthcare-associated bloodstream infections in children [4-8]. IAI is more often associated with hematological malignancies and solid tumors. Strong recommendations concerning prophylactic treatment for IAI have been published [9]. Although Candida albicans is still the main Candida sp. associated with ICI in children, a strong trend toward the emergence of Candida non-albicans has been observed. This could be linked to the use of fluconazole prophylaxis in some patients [2,4]. The epidemiology/risk factors for IFI are quite different between previously healthy children hospitalized in the pediatric intensive care unit (PICU) and children whose hospitalization is related to malignancy or a severe hematological disease (leukemia). Indeed, in the second group, the reported incidence is approximately 5% with a mortality rate of approximately 60% [10]. The crude mortality of patients with IFI is 32% [11]. The mortality rate due to IAI in children is approximately 70% despite appropriate treatment, whereas it is between 20% and 30% for ICI [5,12].In France, a 1-day national survey of nosocomial infections performed in 2001 included 21,596 children younger than aged 18 years (7.1% of all hospitalized children) [13]. Overall, 2.4% presented with a nosocomial infection (1.2% for newborns and 3.3% for children). ICI, in this study, accounted for 4.4% of all infections, regardless of which unit the children were hospitalized in. The rate of nosocomial infections in children hospitalized in PICUs was approximately 15%