Comparing tuberculin skin test and interferon γ release assay (T-SPOT.TB) to diagnose latent tuberculosis infection in household contacts
The Korean Journal of Internal Medicine
; : 486-496, 2017.
Article
in En
| WPRIM
| ID: wpr-138429
Responsible library:
WPRO
ABSTRACT
BACKGROUND/AIMS: The tuberculin skin test (TST) and interferon γ release assay are currently used as diagnostic tools to detect latent tuberculosis (TB) infection; however, there are inconsistencies about the degree of agreement between the tests. We aimed to evaluate the concordance rate between the two tests in household contacts of a country with intermediate TB burden, where most people were vaccinated. METHODS: We recruited household contacts who spent > 8 hours daily with patients with microbiologically confirmed active pulmonary TB, and received both TST and T-SPOT.TB (Oxford Immunotec) simultaneously. The degree of agreement was analysed according to TST cutoff and Bacille Calmette-Guerin (BCG) vaccination status. Relevant factors were analysed to establish the association with TST or T-SPOT.TB. RESULTS: Among 298 household contacts, 122 (40.9%) were spouses, and 250 (83.9%) had received BCG vaccination. In the contact sources, 117 (39.3%) showed a positive result for acid-fast bacillus (AFB) sputum smear and 109 (36.6%) had cavities. The highest agreement rate of 69.5% and κ value of 0.378 were found with a 10 mm cutoff. Spouse, time interval from TB diagnosis to test, and AFB sputum smear positivity were significantly associated with a positive result for T-SPOT.TB. Sex, BCG vaccination, and cavity on chest computed tomography were related to TST positivity. CONCLUSIONS: The present study suggested it was not possible for TST and T-SPOT.TB to replace each other because of considerable discrepancy between the two tests in household contacts in a country with intermediate TB prevalence.
Key words
Full text:
1
Database:
WPRIM
Main subject:
Skin
/
Sputum
/
Thorax
/
Bacillus
/
Tuberculin
/
Skin Tests
/
Tuberculin Test
/
Family Characteristics
/
Prevalence
/
Interferons
Type of study:
Diagnostic_studies
/
Prevalence_studies
Limits:
Humans
Language:
En
Journal:
The Korean Journal of Internal Medicine
Year:
2017
Document type:
Article