Latent tuberculosis infection: Difference between revisions
From IDWiki
(→) |
No edit summary |
||
| Line 1: | Line 1: | ||
| − | = Definition = |
+ | == Definition == |
* Prior exposure to TB |
* Prior exposure to TB |
||
* Goal is to identify those who are at increased risk of developing active TB and would benefit from treatment |
* Goal is to identify those who are at increased risk of developing active TB and would benefit from treatment |
||
| − | = Investigations = |
+ | == Investigations == |
* Tuberculin skin test (TBST) |
* Tuberculin skin test (TBST) |
||
| Line 12: | Line 12: | ||
** Preferred for those who have received BCG after infancy |
** Preferred for those who have received BCG after infancy |
||
| − | = Positive TBST = |
+ | == Positive TBST == |
# Is it truly positive? |
# Is it truly positive? |
||
| Line 28: | Line 28: | ||
#* baseline liver enzymes and vision testing |
#* baseline liver enzymes and vision testing |
||
| − | = Further Reading = |
+ | == Further Reading == |
* [http://blogs.jwatch.org/hiv-id-observations/index.php/common-curbsides-the-tuberculin-skin-test-and-igra-that-dont-agree/2014/11/10/ TBST vs. IGRA for latent TB] |
* [http://blogs.jwatch.org/hiv-id-observations/index.php/common-curbsides-the-tuberculin-skin-test-and-igra-that-dont-agree/2014/11/10/ TBST vs. IGRA for latent TB] |
||
| − | = Tools = |
+ | == Tools == |
* [http://www.tstin3d.com/en/calc.html TST in 3D online TBST/IGRA Interpreter] |
* [http://www.tstin3d.com/en/calc.html TST in 3D online TBST/IGRA Interpreter] |
||
Revision as of 11:23, 17 August 2019
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
Further Reading
Tools
References
- ^ Canadian Tuberculosis Standards. 7th edition. ed. Template:ISBN. OCLC 978699031.
