Comparison of Alternative Meat Inspection Regimes for Pigs From Non-Controlled Housing - Considering the Cost of Error.

Denmark has not had cases of bovine tuberculosis (bovTB) for more than 30 years but is obliged by trade agreements to undertake traditional meat inspection (TMI) of finisher pigs from non-controlled housing to detect bovTB. TMI is associated with higher probability of detecting bovTB but is also more costly than visual-only inspection (VOI). To identify whether VOI should replace TMI of finisher pigs from non-controlled housing, the cost of error - defined here as probability of overlooking infection and associated economic costs - should be assessed and compared with surveillance costs. First, a scenario tree model was set up to assess the ability of detecting bovTB in an infected herd () calculated for three within-herd prevalences, (1, 5 and 10%), for four different surveillance scenarios (TMI and VOI with or without serological test, respectively). was calculated for six consecutive 4-week surveillance periods until predicted bovTB detection (considered high-risk periods ). 1- was probability of missing all positives by each . Next, probability of spread of infection, and number of infected animals moved were calculated for each . Costs caused by overlooking bovTB were calculated taking into account , 1-, eradication costs, and trade impact. Finally, the average annual costs were calculated by adding surveillance costs and assuming one incursion of bovTB in either 1, 10 or 30 years. Input parameters were based on slaughterhouse statistics, literature and expert opinion. Herd sensitivity increased by high-risk period and within-herd prevalence. Assuming =5%, reached median 90% by 2nd for TMI, whereas for VOI this would happen after 6th . Serology had limited impact on . The higher the probability of infection, the higher the probability of detection and spread. TMI resulted in lowest average annual costs, if one incursion of bovTB was expected every year. However, when assuming one introduction in 10 or 30 years, VOI resulted in lowest average costs. It may be more cost-effective to focus on imported high-risk animals coming into contact with Danish livestock, instead of using TMI as surveillance on all pigs from non-controlled housing.