Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- Part 1 Diagnosis, host defence and antimicrobials
- Part 2 Respiratory infections due to major respiratory pathogens
- Part 3 Major respiratory syndromes
- 17 Community-acquired pneumonias
- 18 Community-acquired fungal pneumonias
- 19 Hospital–acquired pneumonia
- 20 Anaerobic bacterial pneumonia, lung abscess, pleural effusion/empyema
- 21 Pneumonia in the immunocompromised host
- 22 HIV-associated respiratory infections
- 23 Infection in children
- 24 Pulmonary infection in cystic fibrosis
- 25 Upper respiratory tract infections
- 26 Respiratory infections associated with foreign travel
- 27 Intensive care management of the critically ill patient with pneumonia
- 28 Diseases associated with persistent or recurrent pulmonary infiltrates
- 29 Chronic air flow obstruction, acute and chronic bronchitis, and bronchiectasis
- 30 Miscellanous agents of pneumonia and lower respiratory tract infections
- Index
17 - Community-acquired pneumonias
from Part 3 - Major respiratory syndromes
Published online by Cambridge University Press: 05 October 2010
- Frontmatter
- Contents
- List of contributors
- Preface
- Part 1 Diagnosis, host defence and antimicrobials
- Part 2 Respiratory infections due to major respiratory pathogens
- Part 3 Major respiratory syndromes
- 17 Community-acquired pneumonias
- 18 Community-acquired fungal pneumonias
- 19 Hospital–acquired pneumonia
- 20 Anaerobic bacterial pneumonia, lung abscess, pleural effusion/empyema
- 21 Pneumonia in the immunocompromised host
- 22 HIV-associated respiratory infections
- 23 Infection in children
- 24 Pulmonary infection in cystic fibrosis
- 25 Upper respiratory tract infections
- 26 Respiratory infections associated with foreign travel
- 27 Intensive care management of the critically ill patient with pneumonia
- 28 Diseases associated with persistent or recurrent pulmonary infiltrates
- 29 Chronic air flow obstruction, acute and chronic bronchitis, and bronchiectasis
- 30 Miscellanous agents of pneumonia and lower respiratory tract infections
- Index
Summary
Definition
The term pneumonia is rarely defined as a clinical entity in the literature, although it can be more clearly defined as a pathological term. However, it is generally agreed to be a lung infection with microorganisms in which the alveoli are involved, with resulting consolidation of the alveolar air spaces. Such a definition distinguishes pneumonia from bronchitis, which involves the airway mucosa and walls. Pneumonia results in impairment of the function of the affected lung tissue in its task of gas exchange, and the consolidation usually also causes shadowing of the affected lung tissue as seen on chest X-ray, so that some element of X-ray opacity is usually a requirement for the clinical diagnosis of pneumonia. In one study, the definition of X-ray opacity sufficient to define pneumonia required ‘either opacity at least involving a segment, or present in more than one lobe, which was neither pre-existing nor of other known cause’.
Some organisms can affect either the airways alone, causing bronchitis, or can involve primarily the alveoli causing pneumonia, but the distinction between bronchitis and pneumonia is not clear-cut, and in some infections there may be a combination of bronchitis and pneumonia in different degrees in different parts of the lungs in the same subject. Examples of such infections include those caused by organisms such as Streptococcus pneumoniae or Haemophilus influenzae.
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- Chapter
- Information
- Infectious Diseases of the Respiratory Tract , pp. 295 - 304Publisher: Cambridge University PressPrint publication year: 1998