TABLE 4.

Incident active TB in relation to initial TB1 and TB2 results

TB2 result for cases of incident active TB (n = 55)	No. of patients with TB1 result
	Negative (<0.2 IU/ml)	Borderline negative (0.2–0.34 IU/ml)	Borderline positive (0.35–0.99 IU/ml)	Positive (≥1.00 IU/ml)	Indeterminate	Total
Negative (<0.2 IU/ml)	7	1				8
Borderline negative (0.2–0.34 IU/ml)	1	1				2
Borderline positive (0.35–0.99 IU/ml)		2	3			5
Positive (≥1.00 IU/ml)	1		2	35		38
Indeterminate					2	2
Total	9	4	5	35	2	55