OBJECTIVE: To analyze factors associated with discordance between tuberculin skin test (TST) and interferon-gamma release assay (IGRA) results among household contacts of pulmonary tuberculosis (PTB) patients. DESIGN: TST (purified protein derivative) and IGRA (QuantiFERON-TB Gold) were performed on household contacts of PTB patients diagnosed between 2006 and 2007 in Salvador, Brazil. Discordant test groups were compared with the TST-/IGRA- group. RESULTS: Of 261 household contacts satisfactorily tested by TST, 145 (55.6%) had positive TST results; of 298 satisfactorily tested by IGRA, 127 (43.1%) had positive results. The test agreement was 0.76 (kappa = 0.53, 95%CI 0.43-0.63). Sixty-one (24%) were discordant: 44 (72%) with TST+/IGRA- and 17 (28%) with TST-/IGRA+ results. Compared to the TST-/IGRA- group, the TST+/IGRA- and TST+/IGRA+ groups were significantly more likely to have a chest X-ray showing old lung scars (OR = 6.8, 95%CI 1.3-35.0; OR = 7.4, 95%CI 2.2-24.4, respectively). The TST-/IGRA+ group was exposed to their index cases for significantly longer than the TST-/IGRA- group (OR = 7.2, 95%CI 1.7-29.3). CONCLUSION: The TST+/IGRA- and TST+/IGRA+ groups shared more similar characteristics with each other than with the TST-/IGRA- group. In a setting endemic for TB, TST results appear to be more suitable in the decision to treat latent TB infection.
OBJECTIVE: To analyze factors associated with discordance between tuberculin skin test (TST) and interferon-gamma release assay (IGRA) results among household contacts of pulmonary tuberculosis (PTB) patients. DESIGN: TST (purified protein derivative) and IGRA (QuantiFERON-TB Gold) were performed on household contacts of PTB patients diagnosed between 2006 and 2007 in Salvador, Brazil. Discordant test groups were compared with the TST-/IGRA- group. RESULTS: Of 261 household contacts satisfactorily tested by TST, 145 (55.6%) had positive TST results; of 298 satisfactorily tested by IGRA, 127 (43.1%) had positive results. The test agreement was 0.76 (kappa = 0.53, 95%CI 0.43-0.63). Sixty-one (24%) were discordant: 44 (72%) with TST+/IGRA- and 17 (28%) with TST-/IGRA+ results. Compared to the TST-/IGRA- group, the TST+/IGRA- and TST+/IGRA+ groups were significantly more likely to have a chest X-ray showing old lung scars (OR = 6.8, 95%CI 1.3-35.0; OR = 7.4, 95%CI 2.2-24.4, respectively). The TST-/IGRA+ group was exposed to their index cases for significantly longer than the TST-/IGRA- group (OR = 7.2, 95%CI 1.7-29.3). CONCLUSION: The TST+/IGRA- and TST+/IGRA+ groups shared more similar characteristics with each other than with the TST-/IGRA- group. In a setting endemic for TB, TST results appear to be more suitable in the decision to treat latent TB infection.
Authors: Jonathon R Campbell; Wenjia Chen; James Johnston; Victoria Cook; Kevin Elwood; Jane Krot; Fawziah Marra Journal: Mol Diagn Ther Date: 2015-04 Impact factor: 4.074
Authors: Shahla Riazi; Barbara Zeligs; Henry Yeager; Stephen M Peters; German A Benavides; Onorina Di Mita; Joseph A Bellanti Journal: Allergy Asthma Proc Date: 2012 May-Jun Impact factor: 2.587
Authors: Gregory James Fox; Nguyen Viet Nhung; Dinh Ngoc Sy; Luu Thi Lien; Nguyen Kim Cuong; Warwick John Britton; Guy Barrington Marks Journal: PLoS One Date: 2012-11-15 Impact factor: 3.240