Performance of Comparative Cervical Tuberculin Test and Serological Methods with Culturing of Nasal Swab in Diagnosis of Bovine Tuberculosis in Cross Breed Cattle Baghdad Iraq: A Comparative Evaluation

Abstract

This study was designed to assess the diagnostic value of Rapid Antigen bovine TB antibody test kit (RAT) and any association with cervical comparative tuberculin test (CCTT), (iELISA) and nasal swabs culturing, among based detection of M. bovis infection. A herd of 21 animal s aged 1 - 8 years c ross bread cattle of college of veterinary medicine . 19 (90.47%) animal s ha d good body condition scores, two bulls included, and 2 (9.52%) cows were fair. Serum samples were collected, analyzed for anti-bovine TB antibody using RAT and iELISA . Also the herd was screened by CCTT . The tests were carried out twice, more than ten month interval, and twelve nasal swabs were taken within second survey. The first survey results revealed prevalence rate: 4 (19.04%) animals considered positive results (one positive and 3 suspected results) for CCTT, while the prevalence rate according to RAT wa s 10 (47.61%). The difference between the two prevalence rate was significant (McNemar chi-statistic = 4.50, p-value = 0.03) Kappa = 0.215 95% confidence interval: f rom -0.128 to 0.558 ; t he strength of agreement is considered to be “ fair ”. The study interprets: sensitivity 30% ; s pecificity 99%. The s econd survey results revealed prevalence rate according to CCTT was 4 (36.36%), while prevalence rate according to RAT was 5 (45.45%) . The difference between the two prevalence was not significant (McNemar chi-statistic = 0.33, p-value = 0.56). Kappa = 0.441 95% confidence interval: f rom -0.087 to 0.968 ; the strength of agreement is considered to be “ moderate ”; sensitivity: 60% ; specificity: 83%. All serum samples and nasal swabs gave negative results for iELISA and culturing respectively. The study concluded that RAT was highly specific, easy, labor and time saving, suggesting its use as screening test in bovine tuberculosis, and CCTT could be used to confirm positive animals screened by RAT, while there wa s no association between RAT, CCTT with body condition scores, iELISA and nasal swabs culture results.