Abstract
This study aimed to address concerns about varied test accuracy for diagnosing bovine brucellosis in the field by estimating the sensitivity (Se) and specificity (Sp) of three commonly used serological tests in naturally-infected smallholder farms in Pakistan.
Materials and methods: Between February and June 2015, a cross-sectional study was conducted in five districts
of Punjab and two districts of Sindh. Sera from cattle (n = 441) and buffalo (n = 621) were diagnosed using the Rose Bengal test (RBT), indirect ELISA (I-ELISA) and competitive ELISA (C-ELISA). A Bayesian latent class analysis was used to estimate the Se and Sp of these in the absence of a gold standard test. The model was fitted under the assumption of conditional independence between the three tests and also conditional dependence. In addition, the model was also fitted with three different prior information of beta distributions to incorporate the prior information from the published literature.
Results: The test with the highest Se was the C-ELISA, with a range from 76.1 to 81.2%. The RBT was found to have the highest Sp (99.1 to 99.4%) of the tests. The results of present study identified discrepancies in Se of
these tests with the published literature, especially for RBT which is usually thought of as a very highly sensitive test. Results echo anecdotal reports and show that RBT has lower Se and higher Sp when used in the field
conditions of the current study. Therefore, we raise issues regarding the reliability of using RBT as a screening test in such conditions, as its use may result in false negative results.
Conclusion: Consequently, we recommended that none of the evaluated tests should be performed in isolation in smallholder scenarios, with the use of RBT and C-ELISA in parallel combination producing optimum Se and Sp for field condition in Pakistan
Materials and methods: Between February and June 2015, a cross-sectional study was conducted in five districts
of Punjab and two districts of Sindh. Sera from cattle (n = 441) and buffalo (n = 621) were diagnosed using the Rose Bengal test (RBT), indirect ELISA (I-ELISA) and competitive ELISA (C-ELISA). A Bayesian latent class analysis was used to estimate the Se and Sp of these in the absence of a gold standard test. The model was fitted under the assumption of conditional independence between the three tests and also conditional dependence. In addition, the model was also fitted with three different prior information of beta distributions to incorporate the prior information from the published literature.
Results: The test with the highest Se was the C-ELISA, with a range from 76.1 to 81.2%. The RBT was found to have the highest Sp (99.1 to 99.4%) of the tests. The results of present study identified discrepancies in Se of
these tests with the published literature, especially for RBT which is usually thought of as a very highly sensitive test. Results echo anecdotal reports and show that RBT has lower Se and higher Sp when used in the field
conditions of the current study. Therefore, we raise issues regarding the reliability of using RBT as a screening test in such conditions, as its use may result in false negative results.
Conclusion: Consequently, we recommended that none of the evaluated tests should be performed in isolation in smallholder scenarios, with the use of RBT and C-ELISA in parallel combination producing optimum Se and Sp for field condition in Pakistan
| Original language | English |
|---|---|
| Pages | 120-120 |
| Number of pages | 1 |
| Publication status | Published - 2018 |
| Event | 15th International Symposium of Veterinary Epidemiology and Economics - Chiang Mai, Thailand Duration: 12 Nov 2018 → 16 Nov 2018 |
Conference
| Conference | 15th International Symposium of Veterinary Epidemiology and Economics |
|---|---|
| Country/Territory | Thailand |
| Period | 12/11/18 → 16/11/18 |