Tuberculosis Flashcards
What organism is tuberculosis caused by?
Mycobacterium tuberculosis
What kind of bacteria is mycobacterium tuberculosis?
Acid fast bacteria
Cell wall rich in lipids
V.hydrophobic, resistant to drying and weak disinfectants
Name the 4 organisms causing M.tuberculosis complex
M.tuberculosis
M.bovis
M.africanum
M.microti
What is first inhaled in primary tuberculosis?
Bacilli
Macrophages do not destroy what in primary tuberculosis?
Bacilli
Where does M.TB multiply and for how long?
inside macrophages for 7-21 days
What happens after a cell mediated response is initiated in primary tuberculosis?
Tubercules form
What are the symptoms of TB?
Cough Afternoon fever Weight loss Blood stained sputum Night sweats
How can active TB be diagnosed?
Clinical examination
Chest x-ray
Sputum test; smear and/or cultures
How can you diagnose latent TB?
Tuberculin skin test
Molecular assays
What would count as a positive skin lesion for tuberculin skin test?
Skin lesion >10mm diameter after 48-72hr
What vaccine is used to prevent TB?
BCG vaccine
What are the first line anti-TB drugs?
Rifampicin, Isoniazid, Pyrazinamide, Ethambutol
What are the side effects of rifampicin?
Liver damage
Hypersensitivity
Decrease activity of other drugs.
Red colour in body fluids
How is rifampicin administered?
IV, IM or oral
What are the side effects of rifampicin?
Hpersensitivity
Peripheral neuropathy
Liver toxicity
Decrease efficacy of hormonal birth control
How is pyrazinamide administered?
Orally
What are the side effects of pyrazinamide?
Joint pain
Liver damage
Hypersensitivity
How is ethambutol administered?
Orally
What are the side effects of ethambutol?
Optic neutitis:reversible
Joint pain
What is the site of action of isoniazid?
Inhibits cell wall synthesis
What is the site of action of of ethambutol?
Inhibits cell wal synthesis
What is the site of action of rifampicin?
Inhibits RNA synthesis
What is the site of action of pyrazinamide?
Disrupts plamsma membrane
Disrupts energy metabolism
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What are the 2nd line anti-TB drugs?
Streptomycin Capreomycin Cycloserine Ciprofloxacin Azithromycin
What is the treatment of active TB?
Rifampicin & isoniazid for 6-9 months.
Pyrazinamide for 2 monhts & ethambutol
What is the treatment of latent TB?
Isoniazid 6 months
OR
Rifampicin & isoniazid 3 months