Predictors of persistently positive Mycobacterium-tuberculosis-specific interferon-gamma responses in the serial testing of health care workers

Table 3 Characteristics of the subjects with inconsistent QFT-GIT results (n = 12)

							TST results		IFN-γ (IU/ml)
ID No.	Age	Sex	Country of birth	Family history of TB (year)	Profession (department/center) - exposure or risk classification	BCG vaccination	Prior TST*	Recent TST (mm)	Baseline	Follow-up	IGRA time interval (weeks)
Conversions^# (n = 3)
079	54	F	Germany	No	Room cleaning (B) - Contact tracing (SNCP, 90 min)^§	Yes	No	10	0.06	0.46	17
151	39	F	Germany	1967	Administration (Pulmonary/G) - Routine screening (medium risk)	No	No	0	0.01	0.46	52
177	50	F	Germany	1990	Nursing (ER/G) - Routine screening (medium risk)	Yes	Neg. (45)	10	0.26	4.33	54
Reversions^# (n = 6)
008	30	F	Turkey	No	Room cleaning (B) - Contact tracing (SNCP, 20 min)^§	Unknown	No	0	22.66	0.01	17
015	38	M	Germany	No	Nursing (Surgery/B) - Contact tracing (SNCP, 44 h)^§	Yes	Neg. (52)	0	0.41	0.00	19
072	54	F	Germany	1955	Nursing (Surgery/B) - Contact tracing (SNCP, 4 h)^§	No	Neg. (5)	10	0.77	0.16	18
095	39	M	Germany	No	Physical therapy (Rehabilitation/B) - Contact tracing (SNCP, 4 h)^§	Yes	Neg. (57)	0	29.34	0.00	16
124	44	F	Germany	No	Physical therapy (Rehabilitation/B) - Contact tracing (SNCP, 3 h)^§	Yes	Neg. (86)	0	0.41	0.00	17
265	26	F	Germany	No	Administration (ER/H) - Contact tracing (SPCP, 8 h)^§	No	No	0	0.40	0.00	22
Discordantly indeterminate (n = 3)
086	50	F	Germany	No	Nursing (Surgery/B) - Contact tracing (SNCP, 9 h)^§	No	Pos. (37)	0	0.00	0.00^†	17
173	20	F	Germany	No	Nursing (Pulmonary/G) - Routine screening (medium risk)	Yes	No	7	0.01^†	0.01	51
187	26	F	Germany	No	Nursing (Surgery/B) - Contact tracing (SNCP, 67 h)^§	Yes	Neg. (60)	0	0.02	0.03^†	21

*The interval between the prior and the recent TST in months is indicated in parentheses. ^#QFT-GIT conversions are defined as baseline IFN-γ < 0.35 IU/ml and follow-up IFN-γ ≥ 0.35 IU/ml, QFT-GIT reversions are defined vice versa. ^§The mean interval between the last exposure to the source case and the baseline evaluation was 17 weeks in individuals initially included in contact investigations. ^†Indeterminate QFT-GIT result due to insufficient IFN-γ mitogen response. B = Bochum; BCG = Bacillus Calmette-Guérin; ER = emergency room; F = female; G = Großhansdorf; H = Hamburg; IFN = interferon; M = male; QFT-GIT = QuantiFERON^®-TB Gold In-Tube; SNCP = smear-negative, culture-positive (tuberculosis source case); SPCP = smear-positive, culture-positive (tuberculosis source case); TST = tuberculin skin test.

ISSN: 1471-2334