S2 E058 Pulm Infections part 2

Influenza

Annual influenza vaccination for everyone older than 6 months.
Supportive care
Zanamivir (Relenza) and oseltamivir (Tamiflu)
- Contraindicated in children under 12 years old
- Expensive
- Must be started within 48 hours of infection
- These may also be used as chemoprophylaxis

Severe cough for weeks which tends to be worse at night
Tearing
Sneezing
Malaise
Rapid consecutive coughs followed by a deep inspiration with characteristic high pitched whoop begins a little later

Vaccination available as Tdap
- Booster vaccination is recommended for adults (why not talk about at what age?)
Macrolides
- Erythromycin
- Azithromycin

Depending on the site of infection
- Upper respiratory infection
- Bronchiolitis
- Pneumonia

Caused by Mycobacterium tuberculosis
Only one in ten progression from latent disease to active disease
TB kills 50% of patients with active disease
TB most often affects the lungs but may be extrapulmonary
Risk factors include overcrowding, malnutrition, smoking, DM and HIV
Granuloma
- TB infection that cannot be clear is walled off by the immune system

Caseating Granuloma – A granuloma where the stuff inside dies due to necrosis and it looks like rotten cheese when you cut it open

Ghon focus
-The caseating granuloma of TB
Ghon Complex
- Ghon focus + nearby lymph node where a caseating granuloma is also forming
Ranke Complex
- Over time Ghon complex becomes fibrotic and calcified and can appear on x-ray
Cleared, Latent, Active

Tuberculin skin test
- Normal healthy low risk person positive test at 15 mm of induration
- Healthcare worker or moderate risk patient positive at 10 mm of induration
- Immunocompromised patients considered positive at 5 mm
Chest x-ray – Findings and location change based on stage of disease
- Primary disease is more likely to be in the middle or lower lung fields and reactivation is more likely to be found in the upper lung fields
Acid fast bacillus stain of sputum
TB can be cultured, but it is slow growing and a culture will take two to six weeks

A vaccination is available but provides inconsistent protection. It is used in many parts of the world, but in North America it is only used for people at high risk.
All cases of TB are reportable
Non adherence to treatment plan is a major cause of treatment failure
- Directly observed therapy is often recommended
Initial 2 month
- intense course of four first line antibiotics
  - Isoniazid(INH)
  - Rifampin
  - Pyrazinamide
  - Ethambutol
Next 4-7 months
- Typically Pyrazinamde and ethambutol are discontinued
Sensitivities are now available to determine appropriate antibiotic treatment
Repeat cultures are monitored