Table 4.

Final Identification of Bacterial and Viral Etiology in 120 Cases of Community-Acquired Pneumonia

Recognized bacterial pathogen	54 (45.0%)a
Recognized bacterial infection + viral coinfection	14 (11.7%)
Respiratory virus alone	16 (13.3%)
Normal respiratory flora	21 (17.5%)
Normal respiratory flora + viral coinfection	10 (8.3%)
Undetermined	5 (4.2%)b
Total	120 (100%)

^aFollowing accepted convention, and, to be able to relate these numbers to those in prior reports, we included in this category13 cases in which a recognized bacterial pathogen was isolated but, based on Gram stain and quantitative culture results, coinfection with normal respiratory flora was thought to play a role.

^bIncludes 2 cases in which polymerase chain reaction (PCR) for influenza virus and respiratory syncytial virus were negative but the full viral respiratory PCR was not done.