Lung Infections Flashcards
Describe the epidemiology of lung infections
Areas poor in resources have a high prevalence
More common in children and elderly
Which lung diseases contribute to the global burden of disease according to DALYs
- Acute lung infection
- Tuberculosis
- COPD
- Asthma
Which pathogens are associated with community acquired pneumonia (CAP)
Rhinovirus
Influenza A or B
Respiratory syncytial virus
Strep. Pneumoniae
S. Aureus
Haemophilius influenza
Which pathogens are associated with hospital-acquired pneumonia
Staphylococcus aureus Pseudomonas aeruginosa Klebsiella species E. Coli Acinetobacter species Enterobacter species
What are some atypical pathogens (not covered by penicillin)
Mycoplasma pneumoniae
Chlamydia pneumonia
Legionella pneumophilia
Which pathogen is the most common cause of bronchitis and sinusitis
Haemophilus influenzae
What are the risk factors of lung disease
Age (babies and elderly) Smoking Excess alcohol Contact with children Poverty and overcrowding Medication e.g. corticosteroids Diabetes Respiratory disease
How can lung disease be assessed
Chest radiograph
Blood test (full blood count, urea and electrolytes, liver function, C-reactive protein)
Arterial blood gasses
Microbiological investigation (sputum and blood culture, urine antigen tests)
How are lung diseases diagnosed
Acute lower respiratory tract symptoms New focal chest signs >1 systemic feature (fever, shivers, aches and pain, temperature >38) No other explanation CRB 65
What is the treatment for lung infection
Oxygen for hypoxia Fluids for dehydration Analgesia for pain (Nebulised saline and chest physiotherapy) Antibiotics
What can viral infection of the lungs lead to
Damage to the epithelium
Mediatory release
Cellular inflammation
Local immune memory
What can damage to epithelium due to viral infection lead to
Loss of cilia
Bacterial growth
poor barrier to antigen
Loss of chemoreceptors
What are some common viral agents for lung infection
Rhinovirus Coronavirus Parainfluenza virus Respiratory syncytial virus Adenovirus Enterovirus
What are some predisposing illnesses to lung infection
Frail elderly
COPD/asthma
Diabetes, obesity, pregnancy
Describe the vaccine for influenza
Imperfect vaccines
Vaccine-induced immunity rapidly wanes
Mainly homotypic immunity
Annual vaccination required
Compare the infection by influenza to RSV
No re-infection by the same strain
vs
Recurrent re-infection with similar strains
Describe the vaccine for RSV
No vaccines
Poor immunogenicity
Vaccine-enhanced disease
Very active research field
What are the effects of RSV
RSV causes cells to obstruct the airways
Bronchioles will be full of inflammatory cells
Major cause of progressive respiratory disease
What are the barriers to infection
Mucociliary clearance in the upper airway Sticky mucus layer Beating cilia propels the mucous Coughing and swallowing Immunoglobulin and macrophages Innate - IgA
Describe pneumonia
Infection of the alveoli
5% deaths
Alveoli are filled with inflammatory cells, fibrin, cell debris, pus and bacteria
Bacteraemia
What are the symptoms of pneumonia
Cough Breathlessness Fever green sputum Confusion (elderly)
Describe bronchiectasis and its treatment
Persistently dilated airways secondary to chronic inflammation
Physiotherapy for sputum clearance
Antibiotics (resistance)
CF/PCD/TB/Allergy/RA
What are the symptoms of bronchiectasis
Breathlessness
Recurrent infections
Chronic fatigue
Which pathogen is a common cause of pneumonia
Strep. Pneumoniae
Produces pneumolysin toxin which perforates the membrane
