Comparison between comparative tuberculin and gamma-interferon tests for the diagnosis of bovine tuberculosis in Ethiopia

Citation
G. Ameni et al., Comparison between comparative tuberculin and gamma-interferon tests for the diagnosis of bovine tuberculosis in Ethiopia, TROP ANIM, 32(5), 2000, pp. 267-276
Citations number
14
Categorie Soggetti
Veterinary Medicine/Animal Health
Journal title
TROPICAL ANIMAL HEALTH AND PRODUCTION
ISSN journal
00494747 → ACNP
Volume
32
Issue
5
Year of publication
2000
Pages
267 - 276
Database
ISI
SICI code
0049-4747(200010)32:5<267:CBCTAG>2.0.ZU;2-7
Abstract
A study to determine and compare the sensitivities and specificities of the comparative cervical tuberculin (CCT) and gamma-interferon (IFN-gamma) tes ts for the diagnosis of bovine tuberculosis was conducted on 30 zebu oxen. The results of the tests were compared with the presence of acid-fast bacil li found by bacteriological culturing and histopathological examinations. T he sensitivity and specificity of CCT test were found to be 90.9% and 100%, respectively. Those of the commercial IFN-gamma test were determined to be 95.5% and 87.7%, respectively. No significant differences were found betwe en the sensitivities (Yates' corrected chi(2) = 0.32; p = 0.57) or the spec ificities (Yates' corrected chi(2) = 2.54; p = 0.11) of the two tests. Furt hermore, a positive correlation (r = 0.76) was recorded between the increas e in skin thickness following injection of bovine purified protein derivati ve (PPD) and the optical density in the gamma-interferon assay with bovine PPD. On the other hand, the correlation (r = 0.47) between the change in sk in thickness following injection of avian PPD and the optical density in th e gamma-interferon assay with avian PPD was relatively weak. On the basis o f this preliminary investigation, it was concluded that the choice between the two tests depends on their cost and simplicity and on livestock managem ent and time factors rather than on their respective diagnostic value.