University of Jos Institutional Repository >
Medical Sciences >
Medical Laboratory Sciences >

Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/1695

Title: Identifying ELISPOT and Skin Test Cut-offs for Diagnosis of Mycobacterium Tuberculosis Infection in The Gambia
Authors: Jeffries, D. J.
Hill, P. C.
Fox, A.
Lugos, M.
Jackson-Sillah, D. J.
Adegbola, R. A.
Brookes, R. H.
Keywords: PPD skin test
Issue Date: 2006
Publisher: International Journal of Tuberculosis and Lung Disease (IJTLD)
Series/Report no.: Vol. 10;No. 2; Pp 192–198
Abstract: SETTING: An urban area, The Gambia. OBJECTIVE: To identify ELISPOT and PPD skin test cut-offs, targeting sensitivity and specificity equivalence. DESIGN: Tuberculosis cases 15 years of age and their household contacts underwent ELISPOT, HIV and PPD skin tests. Cases and contacts sleeping in a different house were used to estimate sensitivity and specificity, providing two planes for estimating cut-offs. Specificity was adjusted for infection from previous exposure using a multivariate discrimination algorithm. RESULTS: The point on the line of intersection of the planes that maximised sensitivity and specificity equivalence occurred at 4 spots (95% confidence interval [CI] 3.5–5, multiplier 0) for CFP-10 and 5.5 spots (4.5–8, multiplier 0 for ESAT-6), yielding a sensitivity and specificity of 76% for both antigens. Combining ESAT-6 and CFP-10 using an ‘or’ statement yielded a maximum equivalence sensitivity and specificity of 76.5% at 6 spots for ESAT-6 and 11.5 spots for CFP-10. For the PPD skin test sensitivity and specificity, an equivalence of 78% occurred at 11 mm induration (9–13 mm). CONCLUSION: An ELISPOT cut-off for ESAT-6 or CFP- 10 could be set at 4–8 spot forming units (20–40 spots per million), with little benefit from combining the results. A cut-off of 9–13 mm for the PPD skin test is reasonable when comparing with the ELISPOT
URI: http://hdl.handle.net/123456789/1695
Appears in Collections:Medical Laboratory Sciences

Files in This Item:

File Description SizeFormat
identifying elispot and skin ....pdf631.93 kBAdobe PDFView/Open
View Statistics

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


Valid XHTML 1.0! DSpace Software Copyright © 2002-2010  Duraspace - Feedback