A qualitative immunoassay as complementary test with tuberculin skin test for detection of tuberculosis in dairy cattle

Document Type : Original Article


1 Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 6511, Egypt.

2 Department of Tuberculosis, Bacterial Diagnostic Products Veterinary Serum and Vaccine Research Institute, Cairo, Egypt.

3 General Authorities for Veterinary Services.


Bovine tuberculosis, caused by Mycobacterium bovis, is a zoonotic disease causing
approximately 6% of total human deaths. Its economic losses are not only a
reduction of 10-20% in milk production and weight, but also infertility and
condemnation of meat. Many serological tests are applied for detection of
tuberculosis. ELISA test has the highest sensitivity and specificity than the other
serological tests for the diagnosis of tuberculosis. Several forms of new technology
were brought into the diagnostic approach to mycobacterial infection. The aim of
this work was to detect bovine tuberculosis by application of different serological
tests. Tuberculin skin test was applied on 2650 cattle, only 63(2.4%) were positive.
Forty eight (76.2%) of the slaughtered positive animals showed visible lesions (VL)
while the other 15 (23.8%) had non-visible lesions (NVL). The bacteriological
examination of the 63 samples revealed isolation of M. bovis from 47 processed
samples (74.6%). The results of the immunoassay test have detected 27 out of the
tuberculin positive cattle, while the ELISA has detected 34 out of the positive
reactor cattle. It was concluded that immunoassay and ELISA tests act as
complementary tests for tuberculin skin test especially in anergic cattle.


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