Pneumonies communautaires non graves : la recherche d'une documentation microbiologique est nécessaire

In community-acquired pneumonia (CAP), the search for the causative agent is the only way to allow a justification of de-escalation of antibiotic therapy or to modify an initially ineffective treatment. Among the most useful ways, the cytobacteriological sputum examination and blood cultures are the most contributory tests. Looking for Legionella pneumophila urinary antigen is useful, whereas pneumococcal urinary antigen is associated with a high proportion of false negatives and PCR tests are the most expensive. Bacterial documentation is mandatory in severe CAP.