Table 1.

Comparison of CA and in-house PCR with culture

SpecimensAmplification systemNo. of culture-positive specimensa that were PCR:No. of culture-negative specimensb that were PCR:Sensitivity (%)Specificity (%)NPV (%)PPV (%)
All (n= 1,527)CA5015211,44176.9298.5698.9770.42
In house596351,42790.7697.6099.5862.72
Smear positiveCA2711396.4275.0075.0096.42
 (n = 32)cIn house28031100.0025.00100.0090.32
Smear negativedCA2314201,43862.1698.5699.0353.48
 (n = 1,495)In house316321,42683.7897.6099.5846.20
  • a Includes only specimens growingM. tuberculosis.

  • b Includes 10 culture-positive specimens growing MOTT.

  • c Includes specimens from TB patients only.

  • d Includes six unspecific positive smears and 10 smear-positive specimens from patients infected with MOTT.