Related Experiment Video
Updated: Aug 19, 2026

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria
Published on: February 23, 2014
Etiology of community-acquired pneumonia treated in an ambulatory setting
Thomas J Marrie1, Melanie Poulin-Costello, Michael D Beecroft
1Department of Medicine, University of Alberta, Edmonton, AB, 2F1.30 WMC, 8440 112 Street, Edmonton, Alberta, Canada T6G 2B7. tom.marrie@ualberta.ca
Background:
Very few studies have addressed the etiology of community-acquired pneumonia (CAP) treated in an ambulatory setting.
Methods:
Patients were recruited from physicians' offices and from Emergency Rooms in Canada. Pneumonia was defined as two or more respiratory symptoms and signs and a new opacity on chest radiograph interpreted by a radiologist as pneumonia. Blood and sputum for culture as well as acute and convalescent serum samples for serology were obtained. Antibodies to Mycoplasma pneumoniae and Chlamydia pneumoniae were determined using enzyme-linked immunosorbent assays.
Results:
Five hundred and seven patients were enrolled in the study; 419 (82%) had blood cultures done, seven (1.4%) of which were positive for Streptococcus pneumoniae; 241 (47.5%) had a sputum processed for culture, 31% of which were positive for a potential respiratory pathogen. 437 (86.2%) had both acute and convalescent serum samples obtained, 148 (33.8%) of which gave a positive result. Overall an etiological diagnosis was made in 48.4% of the patients. M. pneumoniae accounted for 15% of the cases, C. pneumoniae 12%, S. pneumoniae 5.9% and Haemophilus influenzae 4.9%.
Conclusions:
Despite considerable effort an etiological diagnosis of CAP treated on an ambulatory basis was made in only half the patients. The most commonly identified pathogens were M. pneumoniae, C. pneumoniae, S. pneumoniae,
Related Concept Videos
Pneumonia I: Introduction
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...
Pneumonia I: Introduction
Atypical Pneumonia
Pneumonia IV: Management
Bacterial Pneumonia Treatment
For bacterial pneumonia, antibiotics serve as the cornerstone of therapy. Initial treatment often begins with empirical antibiotics, tailored to the anticipated causative organism and adjusted based on culture results. Key antibiotic choices include:
Pneumonia V: Nursing management and Prevention
The nurse must practice strict medical asepsis and adhere to infection control guidelines to minimize healthcare-associated infections.
Enhance airway patency
Position the patient correctly to facilitate drainage of the affected lung segments. Manual or mechanical percussion and vibration can also be employed.
Pneumonia III: Complications and Assessment
