OBJECTIVES: To evaluate individuals at high risk for tuberculosis exposure who had a history of a positive tuberculin skin test (TST) result in order to determine the prevalence of unsuspected negative TST results. To confirm these findings with the QuantiFERON-TB test (QFT), an in vitro whole-blood assay that measures tuberculin-induced secretion of interferon-gamma. METHODS: This survey was conducted from November 2001 through December 2003 at 3 sites where TST screening is regularly done. Detailed histories and reviews of medical records were performed. TSTs were placed and read by 2 experienced healthcare workers, and blood was drawn for QFT. Any subject with a negative result of an initial TST during the study (induration diameter, <10 mm) underwent a second TST and a second QFT. The TST-negative group comprised individuals for whom both TSTs had an induration diameter of <10 mm. The confirmed-negative group comprised individuals for whom both TSTs yielded no detectable induration and results of both QFTs were negative. RESULTS: A total of 67 immunocompetent subjects with positive results of a previous TST were enrolled in the study. Of 56 subjects who completed the TST protocol, 25 (44.6%; 95% confidence interval [CI], 31.6%-57.6%) were TST negative (P<.001). Of 31 subjects who completed the TST protocol and the QFT protocol, 8 (25.8%; 95% CI, 10.4%-41.2%) were confirmed negative (P<.005). CONCLUSIONS: A significant proportion of subjects with positive results of a previous TST were TST negative in this study, and a subset of these were confirmed negative. These individuals' TST status may have reverted or may never have been positive. It will be important in future studies to determine whether such individuals lack immunity to tuberculosis and whether they should be considered for reentry into tuberculosis screening programs.
OBJECTIVES: To evaluate individuals at high risk for tuberculosis exposure who had a history of a positive tuberculin skin test (TST) result in order to determine the prevalence of unsuspected negative TST results. To confirm these findings with the QuantiFERON-TB test (QFT), an in vitro whole-blood assay that measures tuberculin-induced secretion of interferon-gamma. METHODS: This survey was conducted from November 2001 through December 2003 at 3 sites where TST screening is regularly done. Detailed histories and reviews of medical records were performed. TSTs were placed and read by 2 experienced healthcare workers, and blood was drawn for QFT. Any subject with a negative result of an initial TST during the study (induration diameter, <10 mm) underwent a second TST and a second QFT. The TST-negative group comprised individuals for whom both TSTs had an induration diameter of <10 mm. The confirmed-negative group comprised individuals for whom both TSTs yielded no detectable induration and results of both QFTs were negative. RESULTS: A total of 67 immunocompetent subjects with positive results of a previous TST were enrolled in the study. Of 56 subjects who completed the TST protocol, 25 (44.6%; 95% confidence interval [CI], 31.6%-57.6%) were TST negative (P<.001). Of 31 subjects who completed the TST protocol and the QFT protocol, 8 (25.8%; 95% CI, 10.4%-41.2%) were confirmed negative (P<.005). CONCLUSIONS: A significant proportion of subjects with positive results of a previous TST were TST negative in this study, and a subset of these were confirmed negative. These individuals' TST status may have reverted or may never have been positive. It will be important in future studies to determine whether such individuals lack immunity to tuberculosis and whether they should be considered for reentry into tuberculosis screening programs.
Authors: Christina Lancioni; Melissa Nyendak; Sarah Kiguli; Sarah Zalwango; Tomi Mori; Harriet Mayanja-Kizza; Stephen Balyejusa; Megan Null; Joy Baseke; Deo Mulindwa; Laura Byrd; Gwendolyn Swarbrick; Christine Scott; Denise F Johnson; LaShaunda Malone; Philipa Mudido-Musoke; W Henry Boom; David M Lewinsohn; Deborah A Lewinsohn Journal: Am J Respir Crit Care Med Date: 2011-10-27 Impact factor: 21.405
Authors: Benjamin D Fox; Mordechai R Kramer; Zohar Mor; Rachel Preiss; Victoria Rusanov; Leonardo Fuks; Nir Peled; Ilanit Haim; Meir Raz; David Shitrit Journal: Lung Date: 2009-10-15 Impact factor: 2.584
Authors: M Pai; R Joshi; S Dogra; A A Zwerling; D Gajalakshmi; K Goswami; M V R Reddy; A Kalantri; P C Hill; D Menzies; P C Hopewell Journal: Int J Tuberc Lung Dis Date: 2009-01 Impact factor: 2.373
Authors: Denise F Johnson; LaShaunda L Malone; Sarah Zalwango; Joy Mukisa Oketcho; Keith A Chervenak; Bonnie Thiel; Harriet Mayanja-Kizza; Catherine M Stein; W Henry Boom; Christina L Lancioni Journal: PLoS One Date: 2014-05-05 Impact factor: 3.240
Authors: Joel Monárrez-Espino; José Antonio Enciso-Moreno; Lucie Laflamme; Carmen J Serrano Journal: Mem Inst Oswaldo Cruz Date: 2014-11 Impact factor: 2.743