Table 1.
Causative agent in community-acquired pneumonia that necessitated admission
| USA18(n=2776) | USA24(n=410) excludes HIV infected patients | Japan2525(n=200) | Spain26(n=90) | Argentina27(n=343) | Thailand30(n=147) | UK29(n=267) | Kenya28(n=281) | |
|---|---|---|---|---|---|---|---|---|
| Diagnostic methods | BC, SC, LC, Ser, LUA, | BC, SC, VC, Ser | BC, SC, MpC, ClC, LC, LUA, Ser | BC, SC, LC, VC, LUA, PCR, Ser, PTNA | BC, SC, Ser, NPVA, LUA | BC, SC, LUA, SpUA, Ser | BC,SC,LC, Ser, LUA, SpUA, Sp CIE | BC,SC, NAC, Ser, SpUA |
| S pneumoniae | 12·6% (5·5%)† | 11% (6%) | 20·5% | 30% | 10% (3%) | 22·4% (17%) | 48% | 46% |
| M pneumoniae | 32·5% (5·4%) | 7% (0·5%) | 9·5% | 22% | 5% (5%) | 6·8% (4·1%) | 3% | 2·5% |
| C pneumoniae | 8·9% (2·4%) | 6 % (1·0%)* | 7·5% | 13% | 3 (3%) | 16·3 (14%) | 13% | 0% |
| H influenzae | 6·6% (0·4%) | 5% (0·25%) | 11% | 7% | 5% (0·3%) | 2·7% (0%) | 7% | 3·6% |
| Staph aureus | 3·4% (0·4%) | 2% (1%) | 5·0% | 2% (0·6%) | 3·4% (3·4%) | 1·5% | 1·4% | |
| Moraxella catarrhalis | 0·76% (0%) | 0·2% (0%) | 3·0% | 1% (0%) | NR | NR | 0% | |
| Legionella spp | 3·0% (2·4%) | 8% (4%) | 1·0% | 1% (0·5%) | 5·4% (3·4%) | 3% | 0% | |
| Enterobacteriaceae | 2·8% (0·7%) | 1% (0·5%) | 2·5% | 1% | 3% (2%) | 11% (6·8%) | <1·4% | 2·5% |
| Pseudomonas spp | 1·7% (0·1%) | 0% | 2·0% | 0% | 2% (0%) | 0·7% (0·7%) | 1% | 0·4% |
| Anaerobes | NR | 16%† | 4·0% | 10% | 2% (2) | 1·1% | NR | |
| Virus | 12·7%5 | 1% (1%) | 3% | 6% | 7% (3%) | NR | 23% | 5·7% |
| Pneumocystis spp | 1·4% | 0% | NR | 8% | 0·3% (0·3%) | NR | NR | NR |
| M tuberculosis | 1·4% | 5% (5%) | NR | 4% | 2% (2%) | NR | Excluded | 8·9% |
| C psittaci | NR | NR | 1·0% | 1% | <1% (0%) | NR | NR | 0% |
| C burnetii | NR | NR | 0·5% | 1% | <1% (0·3%) | NR | 0·7% | 0% |
| Other agents | 05% | 0·7% (0·7%) | 2·0% | 3% | 3% | 6·1% | 2% | |
| (S Milleri) | ||||||||
| Mixed infection | 2% | 8% | NR | NR | 6% | 6·1% | NR | 11% |
| Unknown | 46% | 41·5% | 17% | 48% | 28·6% | 25% | 35% | |
BC=blood cultures. SC=routine sputum culture and test for tuberculosis. MpC=M pneumoniae culture. ClC=Chlamydia spp culture. LC= Legionella spp culture. VC=viral culture; PTNA=percutaneous transthoracic needle aspirate culture. NVA=nasopharyngeal viral antigen detection. Ser=Serological detection. LgUA=Legionella spp urinary antigen. SpUA=Strep pneumoniae urinary antigen. Sp CIE=counter immune electrophoresis for S pneumoniae. NR=not reported.
Listed as Chlamydia spp.
Listed as “aspiration”. Data are total proportion of cases, ie, both definitive and presumptive diagnoses; number in parentheses is proportion of definitive diagnoses. Definitive diagnosis assigned by one of the following criteria: CAP pathogen cultured from a normally sterile site; a noncommensal organism (eg, Mycobacteriumtuberculosis, Legionella spp) was identified from any site; a positive urinary antigen, a positive PCR test, or when paired serological testing revealed a significant increase in antibody titre. A presumptive diagnosis was assigned when growth of a pathogen in sputum culture was accompanied by a gram stain showing a compatible organism or when one high serum antibody titre was noted for a pathogen. Although Ruiz-Gonzales 26 did not specifically define the status of diagnostic criteria as definite or presumptive, the methods used can be accepted as representing definite diagnosis criteria.