Factors Associated with Missed Detection of Mycobacterium tuberculosis by Automated BACTEC MGIT 960 System

Table 1

Proportion of false-negative culture results determined by MGIT among specimens belonging to different grades of AFB smear.

Grade of AFB smear	Total	Number of positive cultures (%)
		MGIT positiv	MGIT false negative
Negative	494	59 (11.9)	4 (0.8)
Scanty	11	9 (81.8)	1 (9.1)
1+	23	20 (87.0)	1 (4.3)
2+	22	21 (95.5)	1 (4.5)
3+	18	17 (94.4)	0 (0.0)
4+	9	7 (77.8)	1 (11.1)
Total	577	133 (23.1)	8 (1.4)

: BACTEC MGIT 960; , .