Cavitation in bacteremic pneumococcal pneumonia. Causal role of mixed infection with anaerobic bacteria

Cavitation developed in 4 of 24 patients with bacteremic pneumococcal pneumonia seen in 1 yr. Two of them had roentgenographic evidence of massive pulmonary gangrene. A total of 3 patients developed putrid sputum at the time of cavitation, proving that anaerobes were present. Culture confirmation of anaerobic etiology (Bacteroides fragilis) was obtained in 1 patient who had a thoracotomy for pulmonary gangrene, Putrid sputum was observed only in cavitary cases. Other clinical and epidemiological features (bilateral infiltrates, alcoholism), which were more frequent in cavitary than in noncavitary cases, are often associated with anaerobic infection. These findings support the hypothesis that concomitant anaerobic infection may be responsible for cavitation in bacteremic pneumococcal pneumonia.