Incidence of Branhamella catarrhalis in the sputa of patients with chronic lung disease.

The incidence of Branhamella catarrhalis in the respiratory tract of adults, especially in the United States, is not known. During the 30-month period from January 1983 to June 1985, 4180 sputum and endotracheal samples from patients in a hospital for chest diseases were evaluated. All samples were acceptable for Gram-stain analysis and/or culture based on published cellular criteria. Using primarily Gram-stain directed cultures, 220 isolates of B. catarrhalis were identified in 180 patients, being present in 5.3% of all sputum cultures and 11.5% of those positive for a pathogen. B. catarrhalis was the fourth most common pathogen identified. It was found in pure culture (124) and mixed culture (96), the latter usually in association with Haemophilus influenzae or Streptococcus pneumoniae. Of the 220 B. catarrhalis isolates, 158 (71.8%) were positive for beta-lactamase. The number and incidence of B. catarrhalis varied, with the organism being most prevalent during the winter months. Despite its frequent presence in sputum, B. catarrhalis was not recovered from pleural fluid or blood during the same period. This study demonstrates the frequent presence of B. catarrhalis in the sputum of adults with chronic lung disease, although the role of this organism as a pathogen was not determined.