What risk groups should be treated based on a > 5mm TST?
- HIV +
- close TB contacts
- Suggestive CXR
- immunocompromised individual
What risk groups should be treated based on a > 10mm TST?
- Recent US immigrants from TB areas (asia, africa, russia, E. europe, L. America)
- IV drug user
- Frequenters of population dense areas
- Mycobacteriaology workers
- Children < 4
- Minors exposed to high-risk adults
What risk groups should be treated based on a > 15mm TST?
Those with no known factors for TB
Who is a close TB contact?
Recenr/prolonged exposere to known/suspected TB.
What are factors for TB transmission?
- Infectiousness of TB
- Type of envirnonment exposed
- Duration of exposure
- Virulency of bacilli
How should close TB contacts be handled?
- evaluated for LTBI and TB disease
- + TST/IGRA --> LTBI Tx
- - TST/IGRA --> retest in 8-10 weeks
When can you start TB treatment on close contacts with a negative TST/IGRA?
- Less than 8-10 weeks have passed since exposure:
- Children < 5
- Living with HIV
What is the progression of TB treatment?
- Initial Phase - 8 wks = 4 drugs used
- Continuation Phase - > 8 wks = drugs used
What's the initial regimine for TB?
Isoniazid, Rifampin, Pyrazinamide, Ethambutol
What are benefits of QFT-G test over TST?
- Only 1 pt visit
- Results in 24 hrs
- No booster phenomenon
- Less likely incorrect reading
- No BCG FP
What are disadvantages of QFT-G testing?
- Samples must be processed in 12 hrs
- Errors in running/interpreting test
- Limited data for minors, immunosuppresive, HIV, blood disorders
What's the basis for the QFT-G test?
- Blood samples mixed with Ag for 16-24 hrs
- Blood cells recognized Ag and release IFN-g
- Results based on amount of IFN-g released