L12. Lower Respiratory Tract Infections Flashcards
What are the 6 major syndromes that occur in the lower respiratory tract?
- Acute Bronchitis
- Acute Exacerbations of Chronic Bronchitis
- Bronchiolitis
- Pneumonia
- Lung Abscess
- Empyema
What is the most common pathogenesis of acute bronchitis?
Usually an URT that has spread down the epithelia causing infection of the bronchi.
Thus is often starts with rhinitis, sore throat, hoarseness and then bronchitis.
What is meant by acute exacerbation of chronic bronchitis? How are they caused?
Chronic Bronchitis leaves the LRT relatively damaged and susceptible to secondary bacterial infection. The acute exacerbations cause small bouts of fever, productive sputum (purulent and blood stained)
What is the most common example of chronic bronchitis?
Chronic Obstruction Pulmonary Disease
What are the usual causative pathogens causing acute exacerbations of chronic bronchitis?
Usually by non-pathogenic pathogens
Pneumoccoi (less virulent)
H.influenzae (non-typable)
What is the major pathogenic cause of Bronchiolitis?
RSV
Why is bronchiolitis more common in infants?
It is believed that children acquire preformed antibodies from their mothers. However in infancy, the immune system isn’t matured enough to form a matured response.
What are the three types of pneumonia?
- Typical (lobar)
- Atypical (diffuse)
- Other
What are the major pathogenic organisms that cause acute bacterial pneumonia?
Pneumococci (80% community acquired) H.influenzae Staphylcocci Klebsiella Legionella TB Chlamyophilia
What is the pathogenesis of acute pneumonia?
Aspiration of microbiota into the alveoli where they replicate and cause inflammation
What are the characteristics of typical pneumonia? What is another name for it?
Lobar Pneumonia
Restricted to one lobe of the lung with subsequent inflammation in only that area (spreading)
What is special about the Chlaymidiophilia pneumoniae bacteria?
Have specific life cycles
Replicating form intracellularly forming inclusion bodies until their burst out and kill the cell in the process
Non-replicating form during extracellular (infectious) form
What are the major pathogenic causes of atypical pneumonia?
Mycoplasma Chlamydia M.catarrhalis influenza RSV adenovirus
What is the pathogenesis (and symptoms) of atypical pneumonia?
Gradual development with cough (less productive, less purulent) with dramatic change in CXR - interstitial tissue inflammation
What are special about mycoplasma bacteria?
have no cell wall (no fixed shapes or sizes) and are important pathogens