Preliminary evaluation of a simple method for detection of bovine tuberculosis: the glutaraldehyde test

The glutaraldehyde test (GT) is performed by mixing whole blood with a 1.25% glutaraldehyde solution. Gelification time is shorter in tuberculous cattle. This test was performed in blood samples obtained from: (a) 48 cattle with bacteriologically confirmed tuberculous lesions; (b) 61 animals with no evidence of tuberculosis at the time of slaughterhouse inspection, 14 of which had hydatid cysts; (c) 260 tuberculin-negative apparently healthy animals, and (d) 21 cattle, also tuberculin-negative but serologically positive for brucellosis. Sensitivity for detecting tuberculosis was 85.4% (41 of 48 animals). The test was negative in 298 out of 307 healthy animals (97.1% specificity). This specificity decreased when the test was applied in animals with evidence of diseases other than tuberculosis. This simple, rapid and inexpensive method could play a complementary role to the tuberculin test for detecting tuberculous cattle, especially in endemic areas with scarce resources and facilities.