Tuberculosis * Flashcards
What is tuberculosis
Chronic granulomatous caseating disease caused by Mycobacterium Tuberculosis
How is TB transmitted
Airborne
-By inhaling droplets of M.TB
(Last long in the environment)
What are the risk factors for TB
Age Ethnic minority Homeless/ Crowded living IVDU/Alcohol abuse Immunosupressed Travel from India
How does Microbacterium cause TB
Primary (dormant)
-Macrophages engulf TB in Hilar lymph where they are destroyed or trapped by granulomatous tissue
Secondary (Active)
-TB becomes active esp. in immunocompromised @ lung apex were it spreads
What is Milliary TB
TB travels via the blood stream
-Millet seeds visible on x-ray
What is the general and resp presentation of a TB patient
Night sweat and weight loss Fever Chronic cough w/ purulent sputum Haemoptysis (Can get bronchiectasis, pneumonia and pleural effusion)
What are some extrapulmonary signs of TB
Meningitis
Skin change
Pericarditis
Joint pain
What are the investigations of TB
CXR
3x Sputum sample w/ Ziehl Neelsen = Bright red
Biopsy and needle aspiration
Mantoux - for latent with BCG vaccine
What are the RIPE drugs for TB
R- Rifampicin
I - Isoniazid
P - Pyramidine
E - Ethambutol
How long should you give the drugs for active and latent TB
ACTIVE
-RIPE = 2 months -RI = 4 months
LATENT
-RI = 6 months -I = 3 months
What are the SE for Rifampicin
Body fluid = red
What are the SE for Isoniazid
Peripheral neuropathy ( Give Pyrodixin in adjunct)
What are the SE for Pyrazinamide
Hepatitis
What are the SE for Ethambutol (Avoid in CKD)
Eye Problem(Optic Neuritis)
What are the 4 microbacteriums part of the Microbacterium Tuberculosis complex (Cause TB)
M Tuberculosis
M Africarium
M Microtis
M Bovis
Where in the world is TB commonly found
South Asia and Subsahran Africa
What is the pathology of TB
TB resists phagocytosis and form caseous granulomata
T cells cause central caseating necrosis = Ghon Focus in Lung upper lobe
Ghon focus spreads to lymph nodes = Ghon Complex
Systemic TB = Milliary TB
Remains in Granulomata = Latent TB (Can reactivate in Immunosupressed)
Describe the features of the MTC
Non motile and non spore forming
Mycolic acid capsule
-fast acid staining w/ ZN = Bright red
Phagocytosis resistant
Slow growing organisms
How do Ghon focus form in TB
T cells cause central granuloma to undergo caseating necrosis of upper lung
How does a Ghon Complex form
Ghon focus spreads to lymph nodes
Forms latent TB (Bad for IC Patients)
What is millairy TB
When the ghon complex spreads sytematically
What investigation can differentiate between latent and active TB
Monteaux skin test
What is the Gold investigation used in TB
3 sputume cultures
Positive acid fast bacilli on ZN stain
Bright red
Which TB drug is avoided in Liver fail
Pyramidine
-SE is hepatitis
