Table 2. New sampling methods and laboratory techniques
TechniqueReferenceCommentDiagnostic yield
    Expectorated sputum[5]Older children<15%
    Induced sputum[65, 66]No age limitation if completed by suction at the end of the inductionIncreases diagnostic yield by 20%
Obtaining two samples is advised
    NPA[67]Young children30% if Xpert used
No equipment required
    GLAThree samples are advised, or carry out in association with induced sputum38%
    FNAB[63]Peripheral lymph nodeHigh diagnostic yield
    TBNA[68]Mediastinal lymph node through fibroscopy, trained endoscopist50%
    String test[69]Children aged >3 years
Bacteriological laboratory
    Smear[5]Low sensitivity (15%)
    MGIT (gold standard)Shortened time versus Löwenstein–JensenLED fluorescence facilitates interpretation
    MODSLess costly than MGIT [72, 73]Less sensitive and specific than MGIT
    Xpert MTB/RIF[70, 71]Twice as sensitive as a smearLower sensitivity than culture (57%)
Allows concomitant rifampicin resistance detection
Immediate resultsShorter time to diagnosis useful in extrapulmonary TB
  • NPA: nasopharyngeal aspirates; GLA: gastric liquid aspirates; FNAB: fine-needle aspiration biopsy; TBNA: transbronchial needle aspiration; MGIT: mycobacterial growth indicator tube; MODS: microscopic observation drug susceptibility; TB: tuberculosis.