5. Respiratory Tract Infections Flashcards
URTI infections (3)
Sinusitis (rhinosinusitis)
Tonsillitis
Pharyngitis
Causes of viral URTIs (5)
Rhinovirus Adenovirus Parainfluenza viruses Influenza viruses Epstein Barr virus (glandular fever)
Main cause of bacterial URTIs
S. pyogenes
Rhinovirus transmission (2)
Direct contact
Brief exposure
Cause of strep sore throat
Group A S. progenies (25% of all cases)
Group A strep virulence factors (4)
Pyrogenic exotoxins
Streptolysins
Hyaluronidase
M protein
Complications of strep sore throat (5)
Otitis media or sinusitis Scarlet fever Rheumatic fever Rheumatic heart disease Acute glomerulonephritis
Definition of bronchitis
Inflammation of tracheobronchial tree
Types of bronchitis
Acute - usually during winter months, viral
Chronic - viral/bacterial, affects 10-25% of population
Definition of chronic bronchitis
Productive cough on most days during at least three months in each of two successive years
Predisposing factors to chronic bronchitis (4)
Smoking
Infection
Air pollution
Allergies
Causes of bronchitis (2)
90% - viral
10% - bacterial
Bronchitis treatment (3)
Decongestants
NSAIDS
Antibiotics (where appropriate)
Complications of untreated viral infections
Secondary bacterial infections
TB mechanisms (3)
Microbiological
Infectivity
Oro-facial implications
Microbiological TB features (3)
Acid fast, aerobic, non-motile, non-encapsulated bacilli
Lipid wall component
Resistant to phagocytosis destruction
TB infectivity features (2)
Spread by droplet nuclei
Ingestion/skin contact rare
TB oro-facial implications (4)
Chronic painless ulcer
Primary oral lesions
Cervical lymphadenitis
Primary jaw TB
TB treatment (2)
Triple therapy
Streptomycin, para-aminosalicylic acid and isoniazid
Long-term TB treatment and benefits (2)
DOTS (direct observed treatment short course)
95% cure rate
Prevents transmission
Pneumonia definition
Inflammatory condition of the lung, especially alveoli
Causes of pneumonia (2)
Typically infection but multifactorial
S. pneumoniae (community-acquired), S. aureus (hospital-acquired)
Features of pneumonia (9)
Sudden/insidious onset Fevers Rigours Malaise SoB Rapid, shallow breathing Cyanosis Cough producing purulent sputum Consolidation of lungs clinically and radiographically
Function of pneumolysin (2)
Inhibits activity of ciliated cells
Cytotocic for alveolar and endothelial cells
Action of pneumolysin (3)
Activates classical complement binding pathway (by binding to Fc of an antibody)
Causes inflammation in lungs, decreases effectiveness of PMNs
Stimulates monocytes to produce cytokines
Clinical management of pneumonia (2)
IV antibiotics and hospitalisation
Vaccination
IV antibiotics and hospitalisation management of pneumonia (3)
Beta-lactams
Erythromycin
Quinolones
Most common type of pneumonia
Legionnaire’s disease
Legionnaire’s transmission (2)
Inhalation of aerosols (contaminated water)
Aspiration of oropharyngeal colonised bacteria
Legionnaire’s symptoms (5)
Flu-like symptoms Progression to severe pneumonia symptoms Mental confusion Renal failure GI symptoms
Legionnaire’s diagnosis (3)
Micro culture
CXR
Antibody level measurements
Legionnaire’s treatment (2)
Erythromycin
Unresponsive to penicillin
