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Relevance, occurrence and significance of positive Aspergillus cultures: aprospective study in adult liver transplant recipients in an intensive care unit

Abstract number: P1423

Cuétara M.S., Alvarez M.E., Alhambra A., Catalán M., Montejo J.C., Pontón J., del Palacio A.

Objective: Most Aspergillus culture isolates from respiratory samples do not represent invasive aspergillosis (IA). Our aim was to prospectively assess the significance of positive Aspergillus cultures of respiratory samples and their relationship with IA in a cohort of high risk liver transplant recipients (LTR) requiring mechanical ventilation in the intensive care unit (ICU).

Methods: Patients were stratified into 3 risk groups (high, intermediate and low) as proposed by Hellinger et al (Liver Transpl 2005: 11: 656). Conventional diagnostic methods, biomarkers (Galactomannan, (1®3)-B-D-glucan), tissue biopsies and necropsies, with the assessment of risk factors, signs, symptoms and radiologic imaging were used for the diagnosis of Invasive Fungal Disease (IFD) as defined by De Pauw et al (Clin Infect Dis 2008; 46: 1813).

Results: 43 adult LTR requiring ICU admission were prospectively studied. Evidence of IFD was documented in 8 patients (2 proven IA and 2 probable IA cases, as shown in the table). 14/43 (32.6%) patients had positive Aspergillus cultures: 3/14 (21.4%) were IA and 11/14 (78.6%) were colonizations (p = 0.0572). The respiratory samples were obtained one day after hospital admission for transplantation in 63.6% (7/11) patients. The overall Aspergillus colonization rate was 25.5% (11/43).

Conclusions: The mortality in the IFD group was 62% (5/8) and in the nonIFD group was 42.85% (15/35). The rate of necropsies was 45% (9/20). An early study of Kusne et al (J Infect Dis 1992; 166:1379), maintains that the isolation of Aspergillus has a high predictive value of IA in LTR, however in our study, the isolation of Aspergillus was not significant possibly due to its small size. It would appear that other factors are needed for the development of IA. The high rate of respiratory Aspergillus colonization one day after hospital admission suggests that fungal colonization of the lungs is present before entry in the hospital (Lass-Flörl C et al Br J Haematol 1999; 104: 745).

Acknowledgments: This investigation was supported by grants Fondo de Investigación Sanitaria, Instituto de Salud Carlos III, Proyecto Investigacion PI 070134 (to MSC), PI 070107 (to A d P) and PI 070376 (to JP), grant IT-26407 of Departamento de Educación, Universidades e Investigación del Gobierno Vasco (to JP) and Saiotek from Departamento de Industria, Comercio y Turismo del Gobierno Vasco (to JP) and an Educational grant from Pfizer (to A d P) and Gilead Spain (to A d P).

Table 1. Risk stratification in 43 LTR: significance of positive Aspergillus cultures in respiratory samples and relationship with invasive aspergillosis

 Non IFD patientsIFD patients
Risk groupHighIntermediateLowHigh (n = 8)
 (n = 19)(n = 3)(n = 13)Non IA1 (n = 4)IA (n = 4)
Patients with positive Aspergillus cultures, n (%)5 (26.3)1 (33.3)5 (19.2)0 (0)3 (75)
  A. fumigatus11200
  A. niger20100
  A. terreus00200
  A. flavus10001
  A. versicolor00002
  A. fumigatus and Rhizopus microsporus10000
Dead patients with     
  positive Aspergillus cultures41103
  negative Aspergillus cultures71120
Patients with necropsy and     
  positive Aspergillus cultures21003
  negative Aspergillus cultures20010
1Non IA: non invasive aspergillosis (1 proven invasive candidiasis; 2 proven zygomycoses; 1 mixed proven invasive candidiasis and zygomycosis).

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Subject:
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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