Volume 11, Number 9—September 2005
Dispatch
Multidrug-resistant Tuberculosis Detection, Latvia
Table 1
Comparison of results from line probe assay for rpoB gene mutations to rifampin susceptibility results on acid-fast bacilli–positive respiratory specimens*†
Line probe rpoB gene mutation results | BACTEC 460 System |
|
---|---|---|
Rifampin-resistant | Rifampin-susceptible | |
Resistant | 31 | 1 |
Susceptible | 2 | 52 |
No amplification | 1 | 1 |
*N = 88; Includes 86 Mycobacterium tuberculosis isolates from BACTEC plus 2 isolates that grew on Löwenstein-Jensen media.
†Compared to results from BACTEC drug susceptibility testing, the line probe assay had a sensitivity of 91% (95% confidence interval [CI] 83–99) and a specificity of 96% (95% CI 92–100). The positive predictive value of the line probe rpoB mutation result for rifampin resistance was 94% (95% CI 88–100), and the negative predictive value was 96% (95% CI 92–100).