Table 2 Frequency of causative pathogens in CAP, stratified based on microbiologic techniquesa
From: Etiology of community-acquired pneumonia in adults: a systematic review
Studies were deigned to recognize: | Bacteria only | Bacteria & ‘atypicals’b | Bacteria, ‘atypicals’ & viruses | Modern Studies: Bacteria and: | ||
|---|---|---|---|---|---|---|
PCR for ‘atypicals’ | PCR for viruses | PCR ‘atypicals’ & viruses | ||||
Streptococcus pneumoniae | 49.6 | 44.9 | 40.7 | 47.6 | 37.1 | 33.0 |
Haemophilus influenzae | 13.8 | 14.0 | 9.7 | 15.6 | 7.2 | 8.6 |
Haemophilus (other) | 3.3 | 3.8 | 0.2 | 3.1 | 0.1 | 0.1 |
Moraxella catarrhalis | 1.7 | 2.0 | 1.2 | 3.5 | 2.2 | 2.4 |
Staphylococcus aureus | 9.1 | 4.8 | 3.7 | 5.9 | 4.7 | 3.9 |
Streptococcus pyogenes | 0.3 | 0.3 | 0.3 | 0.2 | 0 | 0.4 |
Streptococcus (other) | 2.1 | 1.2 | 1.2 | 0.3 | 0.1 | 0.7 |
Neisseria meningitidis | 0.3 | 0.04 | 0.1 | 0 | 0.02 | 0.0 |
Klebsiella | 4.5 | 2.1 | 1.3 | 2.3 | 1.6 | 0.7 |
Enterobacter | 0.4 | 0.4 | 0.2 | 0.2 | 0 | 0.0 |
Enterobacteriaceae (other) | 4.8 | 4.1 | 2.6 | 2.0 | 2.8 | 2.7 |
Pseudomonas | 2.4 | 2.2 | 2.9 | 1.9 | 4.5 | 0.8 |
Gram negative rods (other or unspecified) | 3.0 | 2.3 | 3.3 | 1.8 | 0.5 | 1.8 |
Anaerobic bacteria | 0.5 | 0.05 | 0.4 | 0.1 | 0 | 0.1 |
Other bacteriac | 1.5 | 3.7 | 1.1 | 6.2 | 5.7 | 0.3 |
Mycobacteria | -- d | 0.5 | 1.04 | 0.3 | 0.03 | 1.8 |
Pneumocystis | – | 0.3 | 1.1 | 1.2 | 0.1 | 0.2 |
Other fungi | – | 0.01 | 0.3 | 0.1 | 0.02 | 0 |
Nocardia | – | 0.03 | 0.05 | 0.03 | 0.03 | 0.04 |
Unspecified atypicals | – | 0.5 | 0.4 | 0.0 | 0 | 0 |
Mycoplasma pneumoniae | – | 8.8 | 10.0 | 10.5 | 3.7 | 8.9 |
Chlamydophila pneumoniae | – | 6.9 | 5.7 | 4.9 | 1.4 | 2.9 |
Chlamydophila (other) | – | 0.3 | 1.04 | 0.4 | 0.2 | 0.2 |
Legionella | – | 8.3 | 6.5 | 6.6 | 3.3 | 6.2 |
Coxiella | – | 0.3 | 1.8 | 0.6 | 0.5 | 0.3 |
Influenza A virus | – | – | 2.4 | 0.1 | 4.7 | 3.4 |
Influenza B | – | – | 0.8 | 0.0 | 0.3 | 1.1 |
Influenza A or B | – | – | 1.3 | 0.3 | 1.2 | 9.2 |
Parainfluenza virus | – | – | 1.0 | – | 0.8 | 4.6 |
Respiratory syncytial virus | – | – | 0.8 | – | 1.5 | 4.7 |
Rhinovirus | – | – | 0.04 | – | 4.1 | 11.5 |
Human metapneumovirus | – | – | 0 | – | 0.4 | 4.1 |
Coronavirus | – | – | 0 | – | 0.3 | 3.2 |
Bocavirus | – | – | 0 | – | 0 | 0.04 |
Herpes simplex virus | – | 0.01 | 0.3 | – | 0 | 0.1 |
Cytomegalovirus | – | – | 0.1 | – | 0.02 | 0 |
Adenovirus | – | – | 0.5 | – | 0.3 | 2.2 |
Varicella | – | 0.03 | 0.2 | – | 0 | 0 |
Virus (unspecified or other) | 1.04 | 0.03 | 1.8 | 0.1 | 9.6 | 0.6 |
Bacterial/viral coinfection | 1.9 | 1.9 | 6.1 | 2.6 | 9.7 | 5.9 |