Tuberculosis Flashcards
What type of bacteria causes TB?
mycobacterium tuberculosis
small rod shaped bacteria
acid fast bacilli
What specialist stain is required to detect mycobacterium tuberculosis?
Zeihl-Neelsen Stain (turns them red against blue background)
How is TB spread?
by saliva droplets from infected people
Where is the most common site of TB?
lungs
What is meant by extra pulmonary TB?
TB outwit the lungs - in lymph nodes, CNS, bones
Describe a TB cold abscess.
firm painless neck abscess caused by TB
no redness, inflammation or pain typically expected from infected abscess
What are the risk factors of TB?
close contacts
high prevalence areas
immunocompromised
malnutrition, homelessness, drug users, smokers, alcoholics
What is the name of the test used to determine whether someone has or had TB?
Mantoux test
Who receives the BCG vaccine?
for those at higher risk of TB and TB negative
How does TB present?
chronic, gradually worsening symptoms
cough/ haemoptysis
lymphadenopathy
lethargy, fever, night sweats, weight loss
erythema nodosum
spinal pain
What two tests can be used to test for an immune response to TB?
Mantoux test
interferon gamma release assay
What investigations are carried out on someone with active TB?
chest x-ray
cultures - deep cough sputum samples
How does the Mantoux test work?
inject tuberculin into forearm
infection creates bleb under skin
after 72 hours, test is read
then measure the induration on the skin and if 5mm or more, positive test
What signs are seen on a chest x-ray in primary TB?
patchy consolidation
pleural effusions
hilar lymphademopathy
How is latent TB treated?
isoniazid + rifampicin for 3 months
or isoniazid for 6 months
How is active TB treated?
rifampicin for 6 months
isoniazid for 6 months
pyrazinamide for 2 months
ethambutol for 2 months
RIPE
Is TB a notifiable disease?
yes
How are patients with active TB kept in hospitals?
in negative pressure rooms
What are the side affects of rifampicin?
red/ orange discolouration of urine/ tears
reduces effects of combined oral contraceptive pill (targets cytochrome p450 enzymes)
What is the side effect of isoniazid?
peripheral neuropathy
What is the side effect of pyranizamide?
hyperuricaemia (high uric acid levels)
results in gout and kidney stones
What are the side effects of ethambutol?
colour blindness
reduced visual acuity
