Invasive aspergillosis in a medical ICU: the spectrum of disease in 89 nonhaematology patients

Using criteria designed for invasive aspergillosis (IA) in neutropenic patients, the present study aimed to determine the impact of IA in different groups of nonhaemato-oncological ICU patients. It is a retrospective analysis of all patients that were hospitalized in the 17-bed medical intensive care unit (MICU) between January 2000 and January 2003.

The inclusion criteria were one or more of the following: microbiological evidence of aspergillosis during stay in the MICU (any positive culture or positive circulating galactomannan) or histopathological evidence of aspergillosis (including autopsy). IA was classified as proven, probable or possible, according to the EORTC/MSG definitions. Aspergillus isolation from a nonsterile site in patients without appropriate clinical setting was considered as 'colonization'.

Between 2000 and 2003, 89 of 1850 patients (4.8%) fulfilled the inclusion criteria.

There were 37 chronic obstructive pulmonary disease patients, nine patients with solid organ transplant recipients, 17 patients with autoimmune diseases, six cirrhosis patients and 20 patients with miscellaneous diseases. Following the EORTC/MSG criteria, the patients were classified as proven IA (n = 30), probable IA (n = 37), possible IA (n = 2) and 'colonization' (n = 20). Mean SAPS II score was 52 with a predicted mortality of 48.6%. Overall mortality was 80% (n = 71). Mortality in the proven and probable groups was 96.7% and 86.5%, respectively. Among the 18 patients who survived, 10 just had 'colonization' with Aspergillus and did not have risk factors for IA.

Postmortem examination was done in 47 out of 71 patients (67%) and 29/47 autopsies (62%) showed hyphael invasion with Aspergillus (mainly the lung as target organ). Among the proven cases (n = 30), 29 underwent autopsy (autopsy rate 97%), and one patient with lupus had a positive bronchial biopsy, was treated and survived. The other autopsies were recruited out of the probable group (n = 14, autopsy rate 44%) and the group with 'colonization' for Aspergillus (n = 4, autopsy rate 40%).

There were five out of the 30 proven cases who did not have compromising host factors according to the EORTC/MSG definitions (three liver cirrhosis, one pneumonia in a 95-year-old man, one Klebsiella sepsis with multiorgan failure).

In conclusion, our study proved that IA is an emerging infectious disease in ICU nonhaemato-oncological patients and there is a broad group of patients, who are at risk of IA. IA was diagnosed in patients without characteristics described in the EORTC/MSG definitions. It seems worthwile to investigate the validity of the available diagnosic tools in that group of patients.