Tuberculosis Flashcards
bacteria that causes tuberculosis?
mycobacterium tuberculosis
why is mycobacterium tuberculosis protected from macrophages?
mycolic acid capsule
why must body form granuloma to section off TB, i.e. why can the macrophages just not kill the mycobacterium tuberculosis?
mycolic acid capsule
main transmission for mycobacterium tuberculosis ?
droplets
how does mycobacterium tuberculosis travel through the body systemically?
lymph (nodes)
4 statuses of TB infection, and define each.
primary - you first get it but contain via granuloma
latent - infection now harboured and you are asymptomatic
secondary - latent activates, happens in immunocompromised
miliary -spreads systemically
how many people have latent TB worldwide?
1.7 billion
Where globally is TB the most prevalent?
- 2 places
South Asia + Sub-Sahara Africa
can TB effect other organs aside the lungs?
yes
purpose of forming granuloma?
section off the TB so it can not spread
what does granuloma contain?
tubercle laden macrophages
% wise how many immunocompetent will successfully form granuloma to section off TB.
90%
risk factors for TB infection?
- 6
Homelessness
Alcohol/drugs/smoking
Immunocompromised: HIV, steroids use, malnutrition.
Silicosis: impairs macrophage
are people who get primary TB will usually asymptomatic.
yes, usually asymptomatic.
most serious complication of TB?
TB meningitis
someone has TB with cavity.
if cavity ruptures what complication will they now get?
pneumothorax
why is right middle lobe syndrome a complication of TB?
big hilar lymph nodes crush the R middle lobe
a latent TB reactivates in an immunocompromised person.
what type of TB is this called now.
secondary active TB
screening test for TB?
mantoux test
what is injected in the classic screening test for TB?
-name, how much, where, route
0.1ml PPD Tuberculin
arm
intradermally
on doing mantoux test how long do you wait before measuring the swelling?
48 hours
pt has mantoux test
swelling is <5mm.
interpretation?
negative
pt has mantoux test
swelling is 5-14mm.
positive
pt has mantoux test
swelling is >14mm.
strongly positive
HIV pt has mantoux test
swelling is 3mm.
is this is a negative result?
no because pt has HIV/
a granuloma calcifies to form what?
and when this thing combines with hilar lymph nodes, what is it called then?
ghon lesion
ghon complex
vaccine for TB and leprosy?
BCG
4 people in which the BCG vaccine is contraindicated?
HIV
history of TB, +ve
Mantoux text
>35 years old
3 people who should get BCG vaccine?
prisoners
healthcare workers
homeless
typical systemic symptoms for TB, (common for lots of infections)?
-4
Fever
weight loss
night sweats
lymphadenopathy
symptoms of TB?
- 8
Haemoptysis Dyspnoea Cough with mucus Chest pain fever weight loss night sweats lymphadenopathy
TB causes a cough.
is there or is there not mucus with the cough?
mucus is present
TB causes haemoptysis.
typically is it small bleeding or lots of bleeding?
small amounts of blood
auscultating on someone with TB,
what may heard (sometimes)?
-1
crackles
you examine someone with TB.
what sign may be present for someone with long-standing TB
clubbing
is CXR diagnostic for TB?
no
is sputum culture diagnostic for TB?
yes
CXR finding for someone with TB?
- 3 things
upper zone cavities
consolidation
big hilar
pt can not tolerate sputum sample.
what is 2nd line Ix that can be done instead?
Bronchoscopy and lavage
what does NAAT stand for?
is this a slow or fast test?
Nucleic acid amplification Test
fast
gold. S test for TB
sputum culture
pt suspected of TB.
how many cough sputum must be taken?
1 of these samples must be taken at a particular time of the day, when is it?
3
early morning
stain used for tuberculosis?
ziehl-neelsen stain
in total how long is active TB management?
after this period what test should you do and why?
6 months
sputum sample, check TB is gone
pt diagnosed with active TB.
what is the Mx?
name of drugs + duration
RIPE for two months
(rifampicin, isoniazid, pyrazinamide, ethambutol)
RI for 4 months.
pt diagnosed with active TB CNS.
Mx for this patient?
- 2 features
antibiotics for 10 months
+
dexamethasone/prednisolone
TB pt has large pleural effusion.
what additional drug class do you give alongside the antibiotics?
steroids
are most TB pts treated as outpatient or inpatients?
outpatient
what is latent nutshell MX.
- 2 options
3 months isoniazid (+pyridoxine) & rifampicin
OR
6 months isoniazid (+pyridoxine)
what is pyridoxine?
vit B6
why is pyridoxine given with isoniazid?
stop peripheral neuropathy side effects
isoniazid:
moa?
SE?
stops mycolic acid synthesis
peripheral neuropathy
rifampicin
moa?
SE?
which pt group often affected by TB are also particularly prone to the said SE?
inhibits bacterial DNA dependent RNA polymerase preventing DNA being transcripted into mRNA
hepatitis
HIV - (hepatits)
Pyrazinamide
moa?
SE? (3)
inhibits fatty acid synthesis
hyperuricaemia (gout), arthralgia, myalgia
inhibits the enzyme arabinosyl transferase which polymerizes arabinose into arabinan:
name of drug?
SE?
Ethambutol
optic neuritis
what is a lung cavity?
colour of it on cxr?
a thick wall of gas in the lung
black
