Tuberculosis

Question 1

By how much is the worldwide TB incidence rate falling by what percentage per year

Answer 1

About 2%

Question 2

TB deaths have fallen by what percentage since 2000

Answer 2

29%

Question 3

How many people are estimated to by infected by TB worldwide

Answer 3

2 billion

Question 4

Examples of countries with high prevalence of TB

Answer 4

India, China, Indonesia, Philippines, Pakistan, Nigeria, Bangladesh, South Africa

Question 5

Number of TB deaths per year

Answer 5

Around 1.6 million

Question 6

Is TB more common in men or women

Answer 6

Men by 2x

Question 7

Vulnerable groups to TB in the UK

Answer 7

People from high prevalence countries
HIV positive
Immunosuppressed
Elderly and neonates
Diabetics 
Those with chaotic lifestyle (1 in 10)

Question 8

Mycobacteria causing TB present in

Answer 8

Soil and water

Question 9

Examples of bacteria that cause TB

Answer 9

M. tuberculosis
M. africanum
M. bovis

Question 10

Problem with culturing bacteria

Answer 10

Very slow growing - long wait to make diagnosis

Question 11

Features of mycobacteria causing TB

Answer 11

Non-motile
Slow growing
Aerobic
Very thick fatty cell wall - causes resistance

Question 12

Transmission of TB

Answer 12

Airborne

Question 13

Exceptionally, M. Boris can be spread by

Answer 13

Consumption of unpasteurised infected cows’ milk

Question 14

Immunopathology of TB

Answer 14

T cell mediated - eliminates mycobacteria but also results in tissue destruction.
Macrophages, epithelioid cells, laghan’s giant cells -> granuloma

Question 15

3 fates of primary infection

Answer 15

Progressive disease
Contained latent
Cleared cured (immune memory)

Question 16

Mycobacteria is spread via

Answer 16

Lymphatic system to draining hilarious lymph nodes

Question 17

Primary TB can progress to

Answer 17

Tuberculosis bronchopneumonia

Milliary TB

Question 18

Tuberculosis bronchopneumonia

Answer 18

Primary focus enlargement
Enlarged hilar lymph nodes compress bronchi - lobar collapse
Enlarged lymph node discharge into bronchus
Poor prognosis = high mortality

Question 19

Miliary TB

Answer 19

Hematogenous spread of bacteria to multiple organs

Widespread small granulomata

Question 20

Post primary disease hypothesis

Answer 20

TB bacteria entering a dormant stage

Balanced stage of replication and destruction by immune mechanisms

Question 21

Clinical presentation of TB

Answer 21

Cough
Fever
Night sweats
Weight loss

Question 22

Classical post-primary TB x-ray presentation

Answer 22

In the apices, fluffy/nodular upper zone, cavitation (10-30%)

Question 23

When to consider CT scan

Answer 23

Normal chest x-ray but clinical suspicion 
Miliary TB
Cavitation and other differential
Lymphadenopathy, alternative diagnosis
Targets for BAL

Question 24

Primary TB x-ray presentation

Answer 24

Pneumonic lesion with enlarged hilar nodes - pleural effusion, mediastinal lymphadenopathy, miliary

Question 25

Sampling bacteria methods

Answer 25

``` Sputum Induced sputum Bronchoscopy with BAL Endobronchial ultrasound with biopsy Lumbar puncture in CNS TB Urine in urogenital TB Aspirate/biopsy from tissue ```

Question 26

Clinical mamagement - TB drugs

Answer 26

``` Isoniazid Pyrazinamide Rifampicin Ethambutol Streptomycin ```

Question 27

Rules of TB treatment

Answer 27

Multiple drug therapy Single agent treatment leads to resistance Therapy for 6 months TB therapy job for committed specialists only Legal requirement to notify all cases Test for HIV, Hep B and C

Question 28

Standard treatment for TB

Answer 28

``` 4 drugs for 2 months then 2 drugs for 4 months (4:2/2:4) Standard 12 tablets per day Pyridoxine with isoniazid Steroids Vitamin D substitution ```

Question 29

Side effects of rifampicin

Answer 29

Orange 'Irn Bru' urine/tears/lenses Hepatitis Induces liver enzymes All normal hormonal contraceptive methods ineffective

Question 30

Side effects of isoniazid

Answer 30

Hepatitis | Peripheral neuropathy

Question 31

Side effects of pyrazinamide

Answer 31

Hepatitis | Gout

Question 32

Side effects of ethambutol

Answer 32

Optic neuropathy

Question 33

BCG vaccination is

Answer 33

Given selectively to groups

Question 34

Groups that are given BCG vaccination

Answer 34

Neonates or unvaccinated children under 5 whose parents/grandparents born in TB prevalent country Unimmunised contacts of cases Unimmunised high risk employees

Question 35

BCG vaccination most effective when given to

Answer 35

Neonates

Question 36

BCG vaccination is ineffective over the age of

Answer 36

16

Question 37

Latent TB screening

Answer 37

Contacts of people with active pulmonary or laryngeal TB aged <65 New entrants from high epidemic areas Outbreaks Pre-biologics Asymptomatic, normal chest x-ray and positive tests

Question 38

Treatment of latent TB

Answer 38

Rifampicin and isoniazid for 3 month, or one alone for 6 months Rifapentine and isoniazid once weekly for 13 weeks (chaotic lifestyle)