Matope G., Muma J.B., Toft N., Gori E., Lund A., Nielsen K., Skjerve E.
Department of Paraclinical Veterinary Studies, University of Zimbabwe, P.O. Box MP 167, Mount Pleasant, Harare, Zimbabwe; Department of Disease Control, University of Zambia, School of Veterinary Medicine, P.O. Box 32397, Lusaka, Zambia; Department of Preclinical Veterinary Studies, University of Zimbabwe, P.O. Box MP 167, Mount Pleasant, Harare, Zimbabwe; Department of Animal Health, National Veterinary Institute, P.O. Box 8156 Dep., N-0033 Oslo, Norway; Ontario Laboratories (Fallowfield), Canadian Food Inspection Agency, 3851 Fallowfield Road, Nepean, ON, K2H 8P9, Canada; Department of Large Animal Sciences, Faculty of Life Sciences, Copenhagen University, Grønnegaardsvej 8, DK 1870 Frederiksberg C, Denmark; Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, P.O. Box 8146 Dep., 0033 Oslo, Norway
Matope, G., Department of Paraclinical Veterinary Studies, University of Zimbabwe, P.O. Box MP 167, Mount Pleasant, Harare, Zimbabwe; Muma, J.B., Department of Disease Control, University of Zambia, School of Veterinary Medicine, P.O. Box 32397, Lusaka, Zambia; Toft, N., Department of Large Animal Sciences, Faculty of Life Sciences, Copenhagen University, Grønnegaardsvej 8, DK 1870 Frederiksberg C, Denmark; Gori, E., Department of Preclinical Veterinary Studies, University of Zimbabwe, P.O. Box MP 167, Mount Pleasant, Harare, Zimbabwe; Lund, A., Department of Animal Health, National Veterinary Institute, P.O. Box 8156 Dep., N-0033 Oslo, Norway; Nielsen, K., Ontario Laboratories (Fallowfield), Canadian Food Inspection Agency, 3851 Fallowfield Road, Nepean, ON, K2H 8P9, Canada; Skjerve, E., Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, P.O. Box 8146 Dep., 0033 Oslo, Norway
The sensitivity (Se) and specificity (Sp) of the Rose Bengal test (RBT), competitive ELISA (c-ELISA), serum (sFPA) and blood (bFPA) fluorescence polarisation assay for brucellosis were evaluated using latent class analysis using sera and whole blood collected from infected cattle reared in smallholder dairy farms of Zimbabwe. The latent class model allowed estimation of Se and Sp in the absence of a gold standard test. The c-ELISA had the highest Se (99.0%; 95% credible posterior interval (CPI): 94.8; 100%), while the RBT and sFPA had the highest Sp (99.0%; 95% CPI: 98.0; 99.6%). The bFPA had the lowest Se (71.3%; 95% CPI: 56.2, 83.5%), while its Sp (96.3%; CPI: 93.9; 98.0%) was marginally higher than that of the c-ELISA (95.4% CPI: 93.7; 96.8%). Therefore based on these data, test regimen using the RBT and c-ELISA could be suitable for diagnosis of brucellosis in smallholder dairies in Zimbabwe. Based on cost and ease of performance, the sFPA may be adopted as a confirmatory test, but its performance may be optimised by altering cut-off points to suit the Zimbabwean conditions. Thus, latent class models provide an alternative method for evaluating Se and Sp of diagnostic tests, which could be used to optimise test performance in different cattle populations. © 2011 Elsevier B.V.