Pneumonia due to Chlamydophila pneumoniae

**Definition:** A disease of the pulmonary system, caused by an infection with the gram-negative bacteria Chlamydia pneumoniae. This disease commonly presents with a gradual onset of cough with low-grade fever. This disease may also present with pharyngitis, laryngitis, and sinusitis. Transmission is by inhalation of infected respiratory secretions. Confirmation is by identification of Chlamydia pneumoniae in a sputum sample.