1: Pulmonary TB Flashcards
1
Q
What is TB
A
Infection mycobacterium tuberculosis
2
Q
In which gender is TB more common
A
Males
3
Q
Which countries have a higher incidence of TB
A
India Indonesia China Nigeria Pakistan
4
Q
What type of organism is mycobacterium TB
A
Gram positive acid-fast bacilli
5
Q
what causes TB in 95%
A
Mycobacterium tuberculosis
6
Q
what does mycobacterium bovis cause
A
GI TB
7
Q
what causes mycobacterium bovis infection
A
Ingestion cow’s milk
8
Q
what are 5 RF for mycobacterium TB
A
- Immunosuppressed
- Alcoholism
- DM
- Malnutrition
9
Q
what are at-risk groups for TB
A
- Healthcare workers
- Prison workers
- Immigrants
- Alcoholics
- HIV
10
Q
when is TB contagious
A
during active infection
11
Q
what are constitutional of TB
A
- Weight Loss
- Night sweats
- Lymphadenopathy
- Malaise
- Fever
- Fatigue
12
Q
what are pulmonary symptoms of TB
A
Dyspneoa
Haemoptysis
13
Q
how does TB lymphadenitis present
A
painless enlarged cervical and supra-clavicular nodes
14
Q
which region does GI TB usually affect
A
ileocaecal valve
15
Q
how does GI TB present clinically and why
A
- colicky abdominal pain and vomiting. Inflammation leads to strictures which causes secondary BO
16
Q
what is pott’s disease
A
Tuberculosis spondylitis
17
Q
how does spinal TB present
A
Tenderness and pain over spine
Rare to have neurological symptoms
18
Q
what is miliary TB
A
Dissemination multiple foci (2mm) around the lung - giving a millet seed appearance on CXR
19
Q
what is CNS TB
A
infection brain and meninges
20
Q
what are 3 risks for CNS TB
A
HIV
Immunocompromised
Under 3-years
21
Q
what is GU TB
A
Infection GU tract presents with flank pain, dysuria and haematuria
22
Q
what can GU TB cause in women
A
Infertility
23
Q
what can GU TB cause in men
A
Prostatitis
24
Q
what is cardiac TB
A
Pericarditis
25
what skin deformity does TB cause
lupus vulgaris: red-brown nodules on the face which then rupture and develop into ulcers
26
Explain primary tuberculosis infection
TB enters lungs (Inferior) where it is phagocytosed by macrophages. TB inhibits fusion of lysosome and phagosome enabling proliferation of bacteria = primary infection
27
What happens after primary infection
3W later: cell mediated response amounts which forms a granuloma surrounding TB. Cells in middle die making it a caseous necrosis
28
Explain Ghon Focus
Granuloma and caseous necrosis
29
What is a Ghon complex
TB in granuloma may spread directly to lymph nodes which is then termed a goon complex
30
What happens if individual becomes immunocompromised
TB may re-activate and spread to upper part of the lung
31
Why does TB spread to upper region of lung
More aerated
32
What happens once TB has spread
May spread haematogenously - causing miliary TB
33
what will be seen on CXR in TB
- Hilar lymphadenopathy
| - Ghon complex (Lower/Middle lobe)
34
what does upper lobe cavitation on CXR indicate
re-activation of TB
35
what else can be seen on CXR in TB
miliary seed appearance
36
what investigations are ordered in TB
```
CXR
Sputum Smear
- and NAAT
Sputum Culture
HIV Test
```
37
how many specimens are required for sputum smear
3 specimens - one must be early morning sample
38
what is used to test for TB on sputum smear
Zeihl-Neelsen stain
39
how will TB present on ziehl nelson stain
Red
40
what medium is used to culture TB
Lowenstein-Jensen
41
what is gold-standard for TB diagnosis
Sputum culture
42
what is problem with sputum culture
Liquid: 1-3W
| Solid culture: 4-8W
43
how will TB present in lowenstein-jensen agar
Rough, Buff and Tough
44
what test is used for rapid TB diagnosis
NAAT
45
explain nucleic acid amplification testing
- looks for DNA or RNA of M.tuberculosis in sputum.
| - results take less than 8h
46
what test should be offered for all individuals with TB
HIV Test
47
what is offered to household contacts of someone with TB
Mantoux testing
48
what is tuberculin skin testing also called
Mantoux testing
49
what is the Mantoux test
Purified protein derivative of TB is injected into the skin. Left 48-72h and then size of induration is measured
50
what is the Mantoux test used for
Screen for latent TB
51
what diameter of induration is negative for TB
<6mm
52
what does 5mm diameter on Mantoux mean
- Has not been exposed to TB or is unvaccinated
53
how should those less than 6mm be managed
- Give BCG vaccine
54
what does induration 6-15mm mean
Hypersensitive to TB - either due to previous vaccination or exposure
55
what does induration more than 15mm mean
Hypersensitive to TB - due to previous infection
56
what is a test used when Mantoux test is equivocal
Interferon gamma release assay (IGRAS)
57
what does IGRAS do
Measures concentration of interferon released from T-cells
58
explain notification of TB
TB is a notifiable disease - inform CDC in 3-days
59
what are 5 causes of false negatives on Mantoux test
- Lymphoma
- Miliary TB
- Sarcoidosis
- Young Child
- HIV
60
explain drug management in TB
4 for 2 and 2 for 4:
Give rifampicin, isoniazid, pyrazinamide and ethambutol for two months.
Give rifampicin and isoniazid for 4-months
61
how is treatment success defined
completion therapy and negative sputum smear
62
how is CNS TB managed
RIPE - for 2 months
RI for 10 months
+ dexamethasone
63
why are steroids given in CNS TB
as TB cells rupture release antigens causing further immune response which can cause oedema and raise ICP
64
what are 2 side effects of rifampicin
- Orange secretions
| - Hepatotoxicity
65
what are 2 side effects of isoniazid
- Hepatoxocitioy
| - Peripheral polyneuropathy
66
what is given with isoniazid to prevent peripheral polyneuropathy
Pyroxidine (vitamin B6)
67
what. are 4 side effects of pyrazinamide
- High Uric Acid
- Hepatotoxicity
- Arthralgia
- Myopathy
68
what is a side effect of ethambutol
Optic neuritis
69
how is ethambutol monitored
Decease colour vision
70
what is multi drug-resistant TB
Resistant to rifampicin and isoniazid
71
what is extensively drug resistant TB
Resistant to rifampicin, isoniazid, one other injectable agent and fluoroquinolone
72
how is TB infection prevented
BCG vaccine
73
what infants are vaccinated against TB
Infants born in region where TB incidence is more than 40 in 100,000
74
if exposure to someone with TB how is person investigated
CXR
| Tuberculin skin test
75
if positive following exposure what is done
treat for active TB
76
if negative following exposure what is done
treat for latent TB (vaccinate)
