Bovine cysticercosis and taeniosis: The effect of an alternative post-mortem detection method on prevalence and economic impact

Abstract

In Europe, bovine cysticercosis (BCC) is detected by routine meat inspection (MI) at the slaughterhouse. The prevalence of BCC in Belgium based on MI is estimated at 0.23%. MI has a known low sensitivity for animals with localised infections and alternative detection techniques should be considered. A mathematical scenario-analysis model was built to determine the current prevalence of BCC in Belgium based on MI results combined with results of dissection of the predilection sites (PS) and the B158/B60 Ag-ELISA on serum of 614 carcasses found negative on MI. Additionally, the impact of the introduction of the B158/B60 Ag-ELISA at slaughter on the prevalence of BCC and taeniosis and on the economic impact related to Taenia saginata was estimated for Belgium. Data for estimating the economic impact were gathered from multiple sources within the meat and human health sectors and included value loss for infected carcasses, inspection costs, carcass destruction costs, cattle insurance costs and costs related to taeniosis (consultation physician, drugs and laboratory test). The model estimated the current prevalence of BCC to be 42.5% (95% CI: 32.4-60.7%) and the sensitivity of the MI for viable and degenerated cysticerci at only 0.54% (95% CI: 0.37-0.71%). A total of 213,344 viable cysticerci (95% CI: 122,962-386.249) were estimated to be present in the infected carcasses in one year and only 408 (95% CI: 356-464) of these were present in the carcasses detected at current MI. The annual number of human taeniosis cases is estimated at 11,000 by using the sale numbers of niclosamide in Belgium. Implementation of the Ag-ELISA at slaughter (Se = 36.37%; Sp = 99.36%) would greatly reduce the prevalence of BCC to 0.6% and the number of taeniosis cases to 89 in year 10. Unfortunately, the accompanying resulting increase in costs for the animal owners, slaughterhouses and the insurance company, would be extremely high in the first years. Cattle owners would suffer losses of up to €21 million in the first year after implementation of the Ag-ELISA (compared to an annual loss of €3.5 million in the current situation), slaughterhouses of €10 million (compared to €200,000 currently) and the insurance company of almost €6 million (compared to €2.3 million profit currently). Therefore, implementation of the Ag-ELISA might not be feasible and other options for controlling T. saginata should be investigated.