A critical appraisal on antibody detector-serodiagnostics for Bovine Tuberculosis

Abstract

Bovine tuberculosis is a worldwide disease that causes great economic losses to the dairy industry and constitutes a serious human public health hazard. In the present study, two types of commercially available immunochromatographic lateral flow kits, namely, IQRT Anigen Rapid Bovine TB Ab kit and Ubio quick VET Bovine Tuberculosis Antibody kit were evaluated for their sero-diagnostic sensitivity and specificity of bovine tuberculosis through the detection of Mycobacterium bovis-specific antibodies in tested serum samples. The results obtained by these kits were compared with the ELISA test, bacteriological examination, and tuberculin skin testing. In this study, out of 3750 dairy cattle tested by single intradermal tuberculin skin test, 69 (1.8%) animals reacted positively. From the slaughtered tuberculin-positive cattle 51 animals (73.9%) showed visible lesions on postmortem examination while the remaining 18 animals (26.1%) showed no visible lesions. Using bacteriological examination of tissue specimens collected, 48 out of the 69 positive tuberculin reactor animals (69.6%) were positive and M. bovis was successfully isolated. Using ELISA for serological examination of serum samples collected prior to skin testing from the 69 positive tuberculin reactors, only 26 cases (37.7%) were positive. The serodiagnosis of bovine tuberculosis using the IQRT Anigen lateral flow kit, which employed recombinant M. bovis MPB70 antigen as capture and detector, could identify only 21 positive cases, which represent 43.8% of 48 bacteriologically identified cases and 30.44% out of the 69 tuberculin positive cases. On the other hand, the Ubio quick VET kit has detected zero% of bovine tuberculosis-positive cattle. It is concluded that the use bovine tuberculosis Antibody Rapid Test Kit alone may be unreliable for the detection of tuberculosis-infected cattle.