OBJECTIVE: To compare the enzyme-linked immunospot (ELISPOT) assay with the tuberculin skin test (TST) in children for the diagnosis of Mycobacterium tuberculosis infection in the Gambia. METHODS: We divided child contacts of sputum smear-positive tuberculosis cases into 3 age categories (<5, 5-9, and 10-14 years) and assessed agreement between the 2 tests plus their relationship to prior Bacille Calmette-Guerin (BCG) vaccination. We categorized a child's level of M tuberculosis exposure according to where he/she slept relative to a case: the same room, same house, or a different house. The relationship between exposure and test result was assessed by multiple logistic regression. RESULTS: In child contacts of 287 cases, 225 (32.5%) of 693 were positive by TST and 232 (32.3%) of 718 by ELISPOT. The overall agreement between tests was 83% and the discordance was not significant. Both tests responded to the M tuberculosis exposure gradient in each age category. The percentage of those who were TST positive/ELISPOT negative increased with increasing exposure. At the lowest exposure level, the percentage of ELISPOT-positive children who were TST negative was increased compared with the highest exposure level. Neither test had evidence of false positive results because of BCG. CONCLUSIONS: In Gambian children, the ELISPOT is slightly less sensitive than the TST in the diagnosis of M tuberculosis infection from recent exposure, and neither test is confounded by prior BCG vaccination. Evidence of reduced TST sensitivity in subjects with the lowest known recent M tuberculosis exposure suggests that, when maximal sensitivity is important, the 2 tests may be best used together.
OBJECTIVE: To compare the enzyme-linked immunospot (ELISPOT) assay with the tuberculin skin test (TST) in children for the diagnosis of Mycobacterium tuberculosis infection in the Gambia. METHODS: We divided child contacts of sputum smear-positive tuberculosis cases into 3 age categories (<5, 5-9, and 10-14 years) and assessed agreement between the 2 tests plus their relationship to prior Bacille Calmette-Guerin (BCG) vaccination. We categorized a child's level of M tuberculosis exposure according to where he/she slept relative to a case: the same room, same house, or a different house. The relationship between exposure and test result was assessed by multiple logistic regression. RESULTS: In child contacts of 287 cases, 225 (32.5%) of 693 were positive by TST and 232 (32.3%) of 718 by ELISPOT. The overall agreement between tests was 83% and the discordance was not significant. Both tests responded to the M tuberculosis exposure gradient in each age category. The percentage of those who were TST positive/ELISPOT negative increased with increasing exposure. At the lowest exposure level, the percentage of ELISPOT-positive children who were TST negative was increased compared with the highest exposure level. Neither test had evidence of false positive results because of BCG. CONCLUSIONS: In Gambian children, the ELISPOT is slightly less sensitive than the TST in the diagnosis of M tuberculosis infection from recent exposure, and neither test is confounded by prior BCG vaccination. Evidence of reduced TST sensitivity in subjects with the lowest known recent M tuberculosis exposure suggests that, when maximal sensitivity is important, the 2 tests may be best used together.
Authors: S A Clark; S L Martin; A Pozniak; A Steel; B Ward; J Dunning; D C Henderson; M Nelson; B Gazzard; P Kelleher Journal: Clin Exp Immunol Date: 2007-08-02 Impact factor: 4.330
Authors: Annie F Luetkemeyer; Edwin D Charlebois; Laura L Flores; David R Bangsberg; Steven G Deeks; Jeffrey N Martin; Diane V Havlir Journal: Am J Respir Crit Care Med Date: 2007-01-11 Impact factor: 21.405
Authors: K Okada; T E Mao; T Mori; T Miura; T Sugiyama; T Yoshiyama; S Mitarai; I Onozaki; N Harada; S Saint; K S Kong; Y M Chhour Journal: Epidemiol Infect Date: 2007-11-08 Impact factor: 2.451
Authors: Ifedayo M O Adetifa; Martin O C Ota; Brigitte Walther; Abdulrahman S Hammond; Moses D Lugos; David J Jeffries; Simon A Donkor; Richard A Adegbola; Philip C Hill Journal: PLoS One Date: 2010-09-01 Impact factor: 3.240