Lower respiratory tract infection with Chlamydia pneumoniae.

Chlamydia pneumoniae, also known as TWAR, is a common respiratory pathogen that can cause pneumonia, bronchitis, sinusitis, and pharyngitis. The clinical similarities between C pneumoniae infection and infection with other respiratory pathogens together with the lack, until recently, of readily available diagnostic tests for C pneumoniae have hindered its recognition and treatment in the outpatient setting. In this report, three patients with acute C pneumoniae infection from the Acute Respiratory Disease Study at the University of Washington are described, and the microbiologic characteristics, epidemiologic characteristics, clinical presentations, diagnosis, and treatment of acute C pneumoniae infection are considered.