tuberculosis

Question 1

is TB globally incerasing or decreasing?

Answer 1

decreasing

Question 2

how many people are infected worldwide

Answer 2

2 billion

Question 3

how is TB spread?

Answer 3

Airborne

Question 4

are all AAFBs are TB

Answer 4

no

Question 5

can tb be spread by Mycobacterium bovis, which can be spread by consumption of unpasteurized infected cows’ milk ??

Answer 5

yes common in uk

Question 6

whats the immunopathology of activated macrophages?

Answer 6

goes to epithelioid cells which creates langhan’s giant cells

Question 7

whats the immunopathology of Accumulation of macrophages, epithelioid & Langhan’s cells

Answer 7

granuloma

Question 8

what does the Th1 cells do?

Answer 8

Eliminates / Reduces number of invading mycobacteria

Question 9

what is tissue destruction a consequence of?

Answer 9

activation of macrophages

Question 10

what part of the body spreads mycobacteria?

Answer 10

lymphatics to draining hilar lymph nodes

Question 11

what are symptoms of tb with primary infection

Answer 11

usually no symptoms, can be fever, malaise
erythema nodosum
rarely chest signs

Question 12

what are the fates of primary infection

Answer 12

progressive disease
contained latent
cleared cured

Question 13

what are the 2 otcomes with primary infections?

Answer 13

Primary infection progresses to Tuberculous bronchopneumonia

Miliary TB (looked like millet seeds on autopsy) develops, with hematogenous spread of bacteria to multiple organs

Question 14

what happens when primary infection progresses to Tuberculous bronchopneumonia

Answer 14

Primary focus continues to enlarge - cavitation
Enlarged hilar lymph compress bronchi, lobar collapse
Enlarged lymph node discharges into bronchus

Question 15

what would it look like on an xray if you had miliary tb

Answer 15

fine mottling

Question 16

do animals develop post-primary disease?

Answer 16

no humans do though

Question 17

what are clinical presentations of TB

Answer 17

cough, fever, sweats, weight loss,

Question 18

what are the tests to determine TB?

Answer 18

Sputum; 3 samples, 8-24hrs gap, at least 1 early morning sample
Induced sputum
Bronchoscopy with BAL
Endobronchial ultrasound (EBUS) with biopsy
Lumbar puncture in CNS TB
Urine in urogenital TB
Aspirate/biopsy from tissue ( lymph-node, bone, joint, brain, abscess …)
Mantoux or IGRA are NOT routinely used in diagnosing active TB

Question 19

what is the treatment of tuberculosis?

Answer 19

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 20

whats the standard treatment for TB?

Answer 20

2 R/H/Z/E + 4 R/H Standard 70kg patient takes 12 tablets daily
6 months duration
7-9 months ( Monoresistance)
12 months (CNS TB, H monoresistance extensive disease)
9-12-18-20 months (MDR-RR TB)

Pyridoxine (Vitamin B6) with isoniazid to reduce risk of neuropathy
Steroids (CNS, Milliar, Pericardial)
Vitamin-D substitution ?

Question 21

side effects of rifampicin

Answer 21

Orange ‘Irn Bru’ urine/tears/lenses

Induces liver enzymes, prednisolone, anticonvulsants

All hormonal contraceptive methods ineffective

Hepatitis

Question 22

side effects of isoniazid

Answer 22

Hepatitis

Peripheral neuropathy (pyridoxine B6)

Question 23

side effects of Pyrazinamide

Answer 23

Hepatitis

Gout

Question 24

side effects of Ethambutol

Answer 24

Optic neuropathy (check visual acuity)

Question 25

who is given the BCG vaccination?

Answer 25

Neonates, or unvaccinated children under 5, whose parents/grandparents were born in a country with an annual incidence of TB of 40/100,000 or greater

Question 26

whats screening for latent TB

Answer 26

Contacts of people with active pulmonary or laryngeal TB who are aged ≤65 years (hepatotoxicity increases with age)
New entrants from high endemic areas
‘Pre-biologics’ (TNF-alpha inhibitors)
Outbreaks

Question 27

treatment for latent TB

Answer 27

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