Table 2

Decision matrix for the evaluation of performance of the direct smear methods against the different gold standards for the 150 matched samples

Direct smear (DS)DS OutcomeGold standards: MGIT cultures
A: culture positive=72B: culture positive=81C: culture positive=68
PNPNPN
ZNP360829153113
DS+ = 44N367052543769
FMP441636243525
DS+ =60N286245453357
CYP391033163316
DS+ =49N336848533566
PiLEDP432139253925
DS+ =64N295742442957
  • Culture specimen decontaminated by NaOH–NALC: A for 10 min; B for 15 min; C for 20 minutes.

  • DS+=number of samples (out of 150 samples) that were AFB positive by direct smear.

  • AFB, acid-fast bacilli; CY, CysCope fluorescence microscopy; FM, mercury vapour fluorescence microscopy; P, positive; PiLED, Primo Star iLED fluorescence microscopy; N, Negative; ZN, Ziehl Neelsen microscopy.