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Báo cáo khoa học: "Economic Aspects of Disease Monitoring with Special Reference to Bovine Paratuberculosis"

Tuyển tập các báo cáo nghiên cứu về bệnh thú y được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành thú y đề tài: Economic Aspects of Disease Monitoring with Special Reference to Bovine Paratuberculosis. | Acta vet. scand. 2001 Suppl. 94 17-25. Economic Aspects of Disease Monitoring with Special Reference to Bovine Paratuberculosis By Larry G. Paisley National Veterinary Institute Norway. Present address Danish Veterinary Laboratory Bulowsvej 27 DK-1790 Copenhagen V Denmark. Email lpa@svs.dk Monte Carlo simulation models were used to evaluate the feasibility and potential results of a proposed national survey of the prevalence of bovine paratuberculosis PTB in dairy herds in Norway. The expected herd prevalence was assumed to be 0.2 in the simulations. Infected herds were classified as detected if 1 animal was sero-positive. With a sample size of 6000 herds at least 1 truly infected herd was detected in 99 of the iterations. The low sensitivity of the ELISA test the assumed low herd prevalence the typical low within-herd prevalence of PTB and the small herd sizes in Norway all present problems in detection of the disease. The results showed that the ratio between false-positive herds and true positive herds detected had a median of 70 1. At the assumed herd prevalence of 0.2 and a cost test of 70 NOK the median cost of detecting 1 infected herd was approximately 900 000 NOK. If 2 positive reactors were needed to classify a herd infected the median cost of detecting 1 infected herd was 5 055 000 NOK. Our results suggest that a randomized national prevalence survey would not be feasible due to the low probability of detecting infected herds and because of the high number of false-positive reactions that would be expected. Mycobacterium paratuberculosis Bovine paratuberculosis ELISA Monte Carlo simulation surveillance Introduction For many years the Norwegian cattle population was apparently free of paratuberculosis PTB . PTB was not diagnosed in Norway during the period 1979 through 1996. Because of import restrictions no cattle were imported between 1987 and 1990. From 1991 through 1997 approximately 1200 predominately beef cattle were imported. In order to prevent .