Tuberculosis

Question 1

What is the epidemiology of TB?

Answer 1

DIsease burden from TB globally falling by 2% per year

The number 1 killer and 2/3 of all TB cases in 8 countries

Question 2

Which diseases are lined to TB?

Answer 2

HIV positive and immunosuppressed

Question 3

Give an example of type of bacteria that causes TB and 3 of its species?

Answer 3

Mycobacteria
Species: Tuberculosis
NTM infections and leprosy

Question 4

Describe the structure of mycobacteria

Answer 4

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

Question 5

What is the transmission of TB

Answer 5

Airborne ( doesnt apply to every patient )

Someone with TB bacteria in their lungs coughs

Question 6

What is the exception to the rule of how TB is spread?

Answer 6

Mycobacterium bovis can be spread by consumption of unpasteurized infected cows milk

Question 7

Why is Th1 cell mediated immunological response a two edged sword?

Answer 7

Eliminates / Reduces number of invading mycobacteria

Tissue destruction is a consequence of activation of macrophages

Question 8

What is the natural history of tuberculosis?

Answer 8

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

Question 9

What are the 3 outcomes of primary infection?

Answer 9

Progressive, contained latent or cleared cured TB

Question 10

How long does miliary, meningeal or pleural TB take to develop?

Answer 10

6-12 months

Question 11

How long does Post primary disease, pulmonary or skeletal take to develop?

Answer 11

1-5years

Question 12

How long does genitourinary or cutaneous tb take to develop?

Answer 12

10-15 years

Question 13

Name the clinical presentation of TB

Answer 13

Cough, fever, sweat and weight loss

Question 14

What are signs to look out for when diagnosing active pulmonary tb?

Answer 14

Mediastinal lympadenopathy, pleural effusion and miliary

Question 15

How to check for the TB? (tests)

Answer 15

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

Question 16

What are the main 4 drugs used to treat TB?

Answer 16

Isoniazid, Pyrazinamide, Rifampicin and Ethambutol

Question 17

What are the main rules to follow during the tuberculosis

Answer 17

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

Question 18

Describe the standard treatment for TB?

Answer 18

Standard 70kg patient takes 12 tablets daily

4drugsfor2months or 2drugsfor4months

6 month duration
Pyridoxine
Steriods
Vitamin D

Question 19

Why use pyridoxine with isoniazid?

Answer 19

Reduces risk of neuropathy

Question 20

What percentage of MTB dead in 2 days when regimen includes isoniazid?

Answer 20

90%

Question 21

What percentage of MTB dead in 14 days when regimen includes rifampicin?

Answer 21

99%

Question 22

What is the side effect of the rifampicin?

Answer 22

Orange irn bru urine/tears/lenses

Hepatitis

Question 23

Describe the latent TB screening

Answer 23

New entrants from high endemic areas, outbreaks and contacts of people with active pumonary or laryngeal TB

Question 24

Describe the treatment of latent TB?

Answer 24

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)

Question 25

Describe the two screening tools for TB

Answer 25

Asymptomatic, with normal CXR and normal examination and positive either Mantoux skin test, or Interferon Gamma Release Assay (IGRA) test