Tuberculosis Flashcards
(25 cards)
What is the epidemiology of TB?
DIsease burden from TB globally falling by 2% per year
The number 1 killer and 2/3 of all TB cases in 8 countries
Which diseases are lined to TB?
HIV positive and immunosuppressed
Give an example of type of bacteria that causes TB and 3 of its species?
Mycobacteria
Species: Tuberculosis
NTM infections and leprosy
Describe the structure of mycobacteria
Aerobic and uniquely has a thick fatty cell wall: ressitant to acid, alkali and detergents. Ressitant to neutrophil and macrophage destruction/
Also not all AAFB are TB
What is the transmission of TB
Airborne ( doesnt apply to every patient )
Someone with TB bacteria in their lungs coughs
What is the exception to the rule of how TB is spread?
Mycobacterium bovis can be spread by consumption of unpasteurized infected cows milk
Why is Th1 cell mediated immunological response a two edged sword?
Eliminates / Reduces number of invading mycobacteria
Tissue destruction is a consequence of activation of macrophages
What is the natural history of tuberculosis?
No preceding exposure or immunity.
Mycobacteria spread via lympthatics to draining hilar lymph nodes
Usually no symptoms, can be fever or malaise.
In majority thre is inital lesion or local lympth node and they heal without or with scar
What are the 3 outcomes of primary infection?
Progressive, contained latent or cleared cured TB
How long does miliary, meningeal or pleural TB take to develop?
6-12 months
How long does Post primary disease, pulmonary or skeletal take to develop?
1-5years
How long does genitourinary or cutaneous tb take to develop?
10-15 years
Name the clinical presentation of TB
Cough, fever, sweat and weight loss
What are signs to look out for when diagnosing active pulmonary tb?
Mediastinal lympadenopathy, pleural effusion and miliary
How to check for the TB? (tests)
Sputum; 3 samples, 8-24hrs gap, at least 1 early morning sample
Bronchoscopy with BAL
Urine
Limbar puncture
Endobronchial ultrasound
Aspurate/biopsy
Mantoux or IGRA not really used
What are the main 4 drugs used to treat TB?
Isoniazid, Pyrazinamide, Rifampicin and Ethambutol
What are the main rules to follow during the tuberculosis
Multiple drug therapy is essential
Single agent treatment leads to drug resistant organisms within 14 days
Therapy must continue for at least 6 months
TB therapy is a job for committed specialists only
Legal requirement to notify all cases
Test for HIV, Hepatitis B and C
Describe the standard treatment for TB?
Standard 70kg patient takes 12 tablets daily
4drugsfor2months or 2drugsfor4months
6 month duration
Pyridoxine
Steriods
Vitamin D
Why use pyridoxine with isoniazid?
Reduces risk of neuropathy
What percentage of MTB dead in 2 days when regimen includes isoniazid?
90%
What percentage of MTB dead in 14 days when regimen includes rifampicin?
99%
What is the side effect of the rifampicin?
Orange irn bru urine/tears/lenses
Hepatitis
Describe the latent TB screening
New entrants from high endemic areas, outbreaks and contacts of people with active pumonary or laryngeal TB
Describe the treatment of latent TB?
Rifampicin & Isoniazid for three months, or
Isoniazid only for six months, or
Rifampicin only for six months, or
Rifapentine & Isoniazide once weekly for 12 weeks (underserved population)
