No (%) of pathogens detected in 267 adults studied according to age
| Pathogen | Total (%) (n=267) | Died (%) | Age <75 years (n=155) | Age ⩾75 years (n=112) |
| Bacterial pathogens | 144 (54) | 19 (13) | 88 (57) | 56 (50) |
| Streptococcus pneumoniae | 129 (48) | 18 (14) | 80 (52) | 49 (43) |
| Haemophilus influenzae | 20 (7) | 1 (5) | 11 (7) | 9 (8) |
| Moraxella catarrhalis | 5 (2) | 0 (0) | 1 (0.6) | 4 (4) |
| Staphylococcus aureus | 4 (1.5) | 2 (50) | 2 (1) | 2 (2) |
| GNEB3-150 | 4 (1.4) | 1 (25) | 3 (1.9) | 1 (0.9) |
| Anaerobes3-151 | 3 (1.1) | 0 (0) | 2 (1) | 1 (0.9) |
| Atypical pathogens | 60 (22) | 3 (5) | 42 (27) | 18 (16) |
| Chlamydia pneumoniae | 35 (13) | 2 (6) | 20 (13) | 15 (13) |
| Mycoplasma pneumoniae | 9 (3) | 0 (0) | 8 (5) | 1 (0.9) |
| Legionella pneumophila | 9 (3) | 1 (11) | 8 (5) | 1 (0.9) |
| Chlamydia spp3-152 | 7 (2) | 0 (0) | 5 (3) | 2 (2) |
| Coxiella burnetti | 2 (0.7) | 0 (0) | 2 (1) | 0 (0) |
| Viral pathogens | 62 (23) | 6 (10) | 36 (23) | 26 (23) |
| Influenza virus A | 50 (19) | 6 (12) | 30 (19) | 20 (18) |
| Influenza virus B | 2 (1) | 0 (0) | 0 (0) | 2 (2) |
| Respiratory syncytial virus | 11 (4) | 0 (0) | 6 (4) | 5 (4) |
| Rhinovirus | 2 (0.7) | 0 (0) | 2 (1.3) | 0 (0) |
| Adenovirus | 1 (0.4) | 0 (0) | 1 (0.6) | 0 (0) |
| Pathogen not identified | 68 (25) | 15 (22) | 33 (21) | 35 (31) |
Pathogens were identified from bronchial washings in two patients (L pneumophilia, influenza A), post mortem lung tissue in one (S pneumoniae), and pleural fluid in one (Bacteroidesspp).
↵3-150 Gram negative Enterobacteriaceae (details in text).
↵3-151 Bacteroides spp isolated from pleural fluid in one patient, Fusobacterium necrophorum from blood of a patient with dental caries, andGemella morbilloram from blood of another patient.
↵3-152 Excluding those found to be diagnostic in C pneumoniae assays.