Table 2. Secondary analysis of the performance of THM-GC-EI/MS compared to smear microscopy and culture on Lowenstein Jensen.

	Culture positive Smear positive	Culture positiveSmear negative	Culture negative	Total samples
THM-GC-EI/MS positive	152	9	34	195
THM-GC-EI/MS negative	53	34	109	196
Indeterminate #	1	1	2	4
Total samples	206	44	145	395

A refined algorithm for interpreting the THM-GC-EI/MS chromatograms, developed by using knowledge from an initial analysis of 395 samples, was applied in a second round of blinded analysis by a newly trained operator.

^#Four samples were not determined due to overloading of the GC column and were excluded from further analysis.