An Early Morning Sputum Sample Is Necessary for the Diagnosis of Pulmonary Tuberculosis, Even with More Sensitive Techniques: A Prospective Cohort Study among Adolescent TB-Suspects in Uganda

Table 2

Mycobacterial yield from EM and spot sputum samples by different culture methods (n = 1862).

Culture method	Results	Spot samples; n (%)	EM samples; n (%)	EM and spot samples; n (%)	Total; n (%)
LJ (P < 0.001)	MTBC positive	1 (0.1)	2 (0.1)	3 (0.2)	6 (0.3)
	MOTT	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)
	Culture negative	1831 (98.3)	1806 (97.0)	1859 (99.8)	1772 (95.2)
	Contaminated	30 (1.61)	54 (2.9)	0 (0.0)	84 (4.5)
MGIT (P < 0.001)	MTBC positive	6 (0.3)	12 (0.6)	3 (0.2)	21 (1.1)
	MOTT	106 (5.7)	119 (6.4)	0 (0.0)	225 (12.1)
	Culture negative	380 (20.4)	301 (16.2)	1859 (99.8)	681 (36.6)
	Contaminated	436 (23.4)	499 (26.8)	0 (0.0)	935 (50.2)

EM: early morning; MTBC: mycobacterium tuberculosis complex, MOTT: mycobacterium other than tuberculosis, LJ: Lowenstein Jensen, MGIT: mycobacterium growth indicator tube. IY: incremental yield, LJ: Lowenstein Jensen, MGIT: mycobacterium growth indicator tube.