Advances in Animal and Veterinary Sciences

Research Article
Adv. Anim. Vet. Sci. 9(12): 2176-2183
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H. I. Hosein1*, Amal M. Abdel-Raouf2, Bahaa S. Madkour2, Amira Mazeed3, Sherin R. Rouby1

1Department of Veterinary Medicine, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 62511, Egypt; 2Department of Animal Medicine, Faculty of Veterinary Medicine, Aswan University, Aswan Egypt; 3Department of Brucella Researches, Animal Health Research Institute, Giza, Egypt.

Abstract | In Egypt, Brucella melitensis has been identified in both animals and humans with severe economic losses and public health risk. The Egyptian government still conducts the test and slaughter policy for the control of brucellosis based on sero-testing which is considered the corner stone of surveillance and control programs. However, none of the commonly used serological procedures has been revealed to be 100% consistent as an effective tool for diagnosis of brucellosis. Cattle populations employed in this study included 1738 lactating cows belonged to three dairy herds with history of brucellosis located at Damietta, Behira, and Sharkia Governorates, Egypt. The aim of this study was to assess the sensitivity and the specificity of the commonly used serological tests using different methods. Brucella melitensis biovar 3 could be recovered from the milk of 92 (46. 46 %) out of 198 lactating cows. Assessment of sensitivity, specificity, positive predictive value and negative predictive value of serological tests using Brucella isolation as the gold standard revealed 96.73%, 48.11%, 61.81% and 94.44% respectively. Parallel testing of 960 dairy cows suggests that using BAPAT, RBPT, cELISA and CFT in a parallel manner created the highest overall sensitivity and specificity when considered as their sum and increased the sensitivity of the screening. The combined sensitivity and specificity of RBPT and CFT of 580 dairy cows using a serial interpretation at individual animal level revealed 30 (5.17%) and 26 (4.48%) respectively. It was concluded that the solution to the problems of epidemiological investigation of Brucella outbreaks to ensure precise diagnosis will require employing a battery of tests possessing different tasks of the immune response. Predictive values were found to be more appropriate than are sensitivity and specificity during screening programs.

Keywords | Brucellosis, Predictive values, RBT, Sensitivity, Specificity