Respiratory Tract Infections 2 Flashcards
(44 cards)
What is pneumonia and how is it confirmed?
It is inflammation of the substance of the lungs. Confirmed using chest radiograph
Describe the difference in pneumonia in children and adults?
- Children - Mainly viral, neonates can develop it from chlamydia trachomatis from mother during birth.
- Adults - Mainly bacterial, the aetiology varies with age, underlying disease, occupational and geographic risk factors.
What are the common causes of viral pneumonia?
- Influenza virus,
- Measles,
- Coronavirus,
- Parainfluenza virus,
- Respiratory syncytial virus,
- Cytomegalovirus,
- Adenovirus
What are some bacterial causes of pneumonia?
- Streptococcus pneumoniae,
- Mycobacterium tuberculosis,
- Haemophilus influenza,
- Pseudomonas aeruginosa,
- Staphylococcus aureus
What are some of the atypical cause of pneumonia?
These are a failure to respond to treatment with penicillin, caused by;
- Mycoplasma pneumoniae,
- Legionella pneumophilia,
- Chlamydia psittaci/pneumoniae,
- Coxiella burnetii.
Describe the anatomical classification of pneumonia
- Lobar pneumonia,
- Bronchopneumonia,
- Interstitial pneumonia,
- Necrotising pneumonia (lung abscesses and destruction of parenchyma)
What are the clinical features of streptococcus pneumoniae infection?
Initially - Abrupt onset, rigors, fever, malaise, tachycardia, dry cough.
Followed by productive cough with rusty sputum, spiky temperature and lobular consolidation
What are the clinical features of mycoplasma pneumoniae?
Fever, dry cough, dyspnoea and lymphadenopathy.
What are the clinical features of haemophilus influenza infection?
Mainly occurs in children, it results in consolidation or patchy bronchopneumonia with persistent purulent sputum and malaise.
What are the clinical features of legionella pneumophila infections?
- It causes legionnaire’s disease
- Results in tachypnoea, purulent sputum and chest x-ray shows consolidation.
- Gram negative bacillus which secretes protease causing lung damage.
- Transmitted by aerosol, not person to person
How do you diagnose legionnaire’s disease?
Gram staining of sputum.
Recognition with serotype specific fluorescent antibody.
- Detection of antigen in urine
- 4-fold rise in antibodies.
Describe clinical features of measles?
Fever, runny nose, Koplik’s spots (only occur in measles) and a characteristic rash. It may cause neurological complications.
- May cause Hecht’s pneumonia
What is the prevention, diagnosis and treatment of measles?
Prevention - Immunisation with MMR vaccine.
Diagnosis - Serology for measles-specific IgM, viral isolation or viral RNA detection.
Treatment - If severe ribavirin or antibiotics for secondary bacterial infections.
What are some of the risk factors for pneumonia?
- Bird contact, Travel/air conditioning, cystic fibrosis, immigration, farming (sheep) and recent influenza.
What are the symptoms of pneumonia?
Cough, breathlessness, weakness and malaise, chest pain (pleural inflammation) and purulent sputum
What are the signs of pneumonia?
- Raised temperature
- Purulent sputum
- Rapid respiration
- Signs of lung consolidation
- Shock
- Cyanosis
How do you diagnose pneumonia?
- History,
- Examination,
- Radiology,
- Sputum,
- Serology,
- Histopathology.
Describe the CURB scores for pneumonia
- Confusion of new onset.
- Blood Urea nitrogen greater that 7mmol/l
- Respiratory rate over 30
- Blood pressure with systolic less than 90 or diastolic less than 60
- Age 65 or older.
Define endemic, epidemic and pandemic disease
endemic - Present in community at all times but at low levels.
Epidemic - Sudden severe outbreak within a region or group.
Pandemic - Occurs when epidemic becomes widespread and affects whole region/continent or world
What are the three types of influenza?
Type A - Epidemics and pandemics, animal reservoir.
Type B - Epidemics but no animal hosts
Type C - Minor respiratory illness
What are some of the type-specific antigens on the surface of influenza?
Haemagglutinin (H) and Neuraminidase (N)
What genetic changes does influenza virus undergo?
Antigenic drift - Small point mutations in the H and N antigens occurs constantly.
Antigenic shift - Sudden major change based on recombination between two different virus stains when they infect the same cell. (produces a virus with novel surface glycoproteins)
What makes a pandemic?
Antigenic shift, lack of immunity, attack rate is high and so it mortality
Describe features of swine flu
Influenza A virus H1N1. Since it was a H1N1 virus there was a high attack rate but low mortality due to a degree of immunity.
