TB Flashcards
1
Q
Reasons for false negative TST
A
Testing during incubation period (2 - 10w) Malnutrition Severe miliary disease or meningitis Young age Immunosuppression Concurrent infection
2
Q
IGRA assay
Detects what
Affcted by BCG or environmental mycobacterium?
A
Interferon gamma released by lymphocytes sensitised to TB specific antigens
These antigens not present on BCG or environmental mycobacterium
3
Q
Why are multiple antibiotics required for TB treatment
A
TB multiplys slowly, lies dormant, drugs only work when replicating
Resistance exists in large population naturally, even prior to treatment commencement
4
Q
What vitamin is depleted by isoniazid?
Who needs supplementation?
A
Pyridoxine
Peripheral neuritis or convulsions
Breast fed, diet low in meat and milk, pregnancy
5
Q
BCG vaccines
Derived from
Effective against
A
Mycobacterium bovis
TB
Leprosy
Variable extent
Reduced risk of miliary and meningitis
