Online data supplement
Microbial aetiology of community-acquired pneumonia and its relation to severity
Catia Cillóniz1-5, Santiago Ewig2, Eva Polverino1-5; Maria Angeles Marcos3, Cristina Esquinas1, Albert Gabarrús1, Josep Mensa4, Antoni Torres1-5.
1Servei de Pneumologia, Institut del Tòrax, Hospital Clinic, IDIBAPS, Universitat de Barcelona, Barcelona – Spain, 2 Department of Pneumology, Thoraxzentrum Ruhrgebiet, Herne und Bochum, Germany; 3 Department of Microbiology, Hospital Clínic, Barcelona, Spain; 4 Department of Infectious Diseases, Hospital Clínic, Barcelona, IDIBAPS, Spain. 5 Centro de Investigación Biomédica En Red- Enfermedades Respiratorias (CibeRes, CB06/06/0028)-Instituto de Salud Carlos III-Ministerio de Ciencia e Innovación, Spain.
Diagnostic Yield of Applied Techniques
Serologic tests were carried out in 1,537 patients and identified the causative organism in 177 (11.5%). Sputum cultures were performed on 1,913 patients and identified a causative organism in 490 (25.6%). Blood cultures were performed on 2,753 patients and identified a causative organism in 333 (12.1%). Urine antigen for L. pneumophila was performed on 2,806 patients and 106 (3.8%) were positive; urine antigen for S. pneumoniae was performed on 1,904 patients and 412 (21.6%) were positive. Pleural fluid cultures were performed in 1,387 patients and identified the causative organism in 47 (3.4%). Nasopharyngeal swabs were performed in 767 patients and 118 (15.4%) were positive. Finally, microbiological analysis of BAL fluid was carried out in 384 patients and identified the causative organism in 198 (51.5%).
Distribution of mixed aetiology
Mixed aetiology / n / (%)Bacterial + bacterial / 67 / (32)
Bacterial + viral / 61 / (29)
Bacterial + atypical / 37 / (18)
Bacterial + other / 14 / (7)
Atypical + virus / 13 / (6)
Atypical + atypical / 11 / (5)
Virus + other / 2 / (1)
Atypical + other / 1 / (0.5)
Other + other / 2 / (1)
Note: Bacterial includes: Streptococcus pneumoniae, H. influenzae, Pseudomonas aeruginosa, E. coli, S. aureus, M. catarrhalis, S. viridans, and K. pneumoniae.
Other includes: Acinetobacter species, Bacteroides fragilis, M. morgai, Enterobacter, Peptostreptococcus species, A. fumigatus, Stenotrophomonas maltophilia, Nocardia species
Figure 1. Aetiology of Community-Acquired Pneumonia by Year (number of patients with known aetiology in specific year)
Note: the figure represents the annual incidence of main microbial pathogens over time among CAP patients with known aetiology. It is to notice that the introduction of the urinary antigen detection method for S. pneumoniae and for L. pneumophila in 2000 gives reason of the sudden increase in the diagnosis of S. pneumoniae in that year. Similarly, the introduction of the RT-PCR method for virus detection in 2004 justifies the increase of viral CAP diagnosis from this year.