Pulmonary Aspergillosis in Patients with Suspected Ventilator-Associated Pneumonia in UK ICUs
Laura Loughlin, Thomas P Hellyer, P. Lewis White, Danny F. McAuley, Andrew Conway Morris, Raquel Posso, Malcolm Richardson, David W. Denning, A. John Simpson, Ronan McMullan
Abstract
Abstract Rationale Aspergillus infection in patients with suspected ventilator-associated pneumonia remains uncharacterized because of the absence of a disease definition and limited access to sensitive diagnostic tests. Objectives To estimate the prevalence and outcomes of Aspergillus infection in adults with suspected ventilator-associated pneumonia. Methods Two prospective UK studies recruited 360 critically ill adults with new or worsening alveolar shadowing on chest X-ray and clinical/hematological parameters supporting suspected ventilator-associated pneumonia. Stored serum and BAL fluid were available from 194 nonneutropenic patients and underwent mycological testing. Patients were categorized as having probable Aspergillus infection using a definition comprising clinical, radiological, and mycological criteria. Mycological criteria included positive histology or microscopy, positive BAL fluid culture, galactomannan optical index of 1 or more in BAL fluid or 0.5 or more in serum. Measurements and Main Results Of 194 patients evaluated, 24 met the definition of probable Aspergillus infection, giving an estimated prevalence of 12.4% (95% confidence interval, 8.1–17.8). All 24 patients had positive galactomannan in serum (n = 4), BAL fluid (n = 16), or both (n = 4); three patients cultured Aspergillus sp. in BAL fluid. Patients with probable Aspergillus infection had a significantly longer median duration of critical care stay (25.5 vs. 15.5 d, P = 0.02). ICU mortality was numerically higher in this group, although this was not statistically significant (33.3% vs. 22.8%; P = 0.23). Conclusions The estimated prevalence for probable Aspergillus infection in this geographically dispersed multicenter UK cohort indicates that this condition should be considered when investigating patients with suspected ventilator-associated pneumonia, including patient groups not previously recognized to be at high risk of aspergillosis.