Latent tuberculosis infection
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Revision as of 02:28, 15 August 2019 by Aidan (talk | contribs) (Aidan moved page Mycobacterium tuberculosis Latent tuberculosis Latent tuberculosis (LTBI) to Latent tuberculosis Latent tuberculosis without leaving a redirect)
Latent tuberculosis infection (LTBI)
Definition
- Prior exposure to TB
- Goal is to identify those who are at increased risk of developing active TB and would benefit from treatment
Investigations
- Tuberculin skin test (TBST)
- Sens 90%, Spec >95
- Interferon-gamma release assay (IGRA)
- Sn 95%, Sp >95%
- Preferred for those who have received BCG after infancy
Positive TBST
- Is it truly positive?
- Consider IGRA
- BCG vaccine can be considered a cause of false positive when
- vaccine given after 12 months of age, and
- patient has no risk factors, and
- either Canadian-born non-Aboriginal, or not from endemic country
- Rule out active TB
- signs/symptoms
- CXR or CT chest
- Sputum x3 if coughing or cavitary lesions
- Evaluate risk of reactivation treatment
- INH 300 daily x9 mo with pyridoxine
- baseline liver enzymes and vision testing
Reading
Tools
References
- ^ Canadian Tuberculosis Standards. 7th edition. ed. Template:ISBN. OCLC 978699031.
