The clinical impact of the detection of potential etiologic pathogens of community-acquired pneumonia.

The etiology of community-acquired pneumonia (CAP) is determined in less than half of the patients based on cultures of sputum and blood plus testing urine for the antigens of Streptococcus pneumoniae and Legionella pneumophila. This study added nasal polymerase chain reaction (PCR) probes for S. pneumoniae, Staphylococcus aureus, and respiratory viruses. Serum procalcitonin (PCT) levels were measured. Pathogens were identified in 78% of the patients. For detection of viruses, patients were randomized to either a 5-virus laboratory-generated PCR bundle or the 17-virus FilmArray PCR platform. The FilmArray PCR platform detected more viruses than the laboratory-generated bundle and did so in less than 2 hours. There were fewer days of antibiotic therapy, P = 0.003, in CAP patients with viral infections and a low serum PCT levels.