Microbial agents and severity in community acquired pneumonia

January 01, 0001

Microbial agents and severity in community acquired pneumonia

There are a number of different pathogens that can cause community-acquired pneumonia (CAP). These Spanish and German researchers examined the microbial agents and severity of CAP. They used two tools, the pneumonia severity index and CURB-65, to characterize the severity of the illness. They analyzed 3523 patients with CAP from both outpatient and inpatient settings.

The researchers found: "The aetiology was established in 1463 patients (42%), of whom 257 died (7%). The ranking of aetiologies varied according to site of care, with increasing frequency of Streptococcus pneumoniae and mixed aetiologies and decreasing frequency of atypical pathogens in hospitalised patients and those in ICUs. The distribution of aetiologies according to severity scores showed corresponding patterns. However, the severity scores were more sensitive to Gram-negative enteric bacilli (GNEB) and Pseudomonas aeruginosa and less sensitive in identifying mixed aetiologies as moderate- and high-risk conditions. Mortality rates according to aetiology and severity scoring showed increasing mortality rates for all pathogens except atypical pathogens. S pneumoniae had the highest number of deaths while GNEB, P aeruginosa, Staphylococcus aureus and mixed aetiologies had the highest mortality rates. Legionella pneumophila was similarly distributed according to site of care and prognostic scores."

The researchers concluded: "CAP due to atypical bacterial pathogens is recognised both clinically and by severity scoring as a low-risk condition. Severity scores are more sensitive in identifying patients with GNEB and P aeruginosa as moderate- and high-risk aetiologies whereas mixed aetiologies may be underestimated."

Pneumonia severity is linked with different pathogens, and severity scores have varying sensitivities depending on the pathogen(s) involved.

For the full abstract, click here.

Thorax 66(4):340-346, April 2011
© 2011 BMJ Publishing Group Ltd & British Thoracic Society
Microbial aetiology of community-acquired pneumonia and its relation to severity. Catia Cillóniz, Santiago Ewig, Eva Polverino, et al. Correspondence to Antoni Torres: [email protected]

Category: R. Respiratory. Keywords: pneumonia, community-acquired, bacteria, severity assessment, mortality, epidemiological study, journal watch.
Synopsis edited by Dr Paul Schaefer, Toledo, Ohio. Posted on Global Family Doctor 12 April 2011

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.