Model for the evaluation of different options for the monitoring of Transmissible Spongiform Encephalopathies in cattle in the European Union (C-TSEMM)
The Cattle TSE Monitoring Model (C-TSEMM) has been developed to evaluate different Transmissible Spongiform Encephalopathy (TSE) monitoring regimes in cattle by estimating the trend of the current BSE epidemic within European Member States (MSs). The model has been developed to investigate various sampling scenarios, including the current system of systematically sampling cattle at certain ages and other options such as random sampling of healthy cattle. The model estimates the minimum underlying prevalence in the adult bovine population for each MS which the monitoring regime would be able to detect, together with the sample size from the healthy slaughter stream required for the monitoring regime to detect a specific underlying prevalence of BSE in the adult population (known as the ‘design prevalence’). The model can also be used to assess the ability of those schemes to detect either the re-emergence of an existing TSE or emergence of a new TSE disease in cattle. It is assumed that any new disease can be detected by current testing assays. Given an alternative monitoring scenario, estimates can be made for the number of years taken for a monitoring regime to detect a significant increase in cases due to the re-emergence/emergence of a TSE disease in cattle and the number of detectable cases and infected animals that would occur in this time. Results in this report are produced for the baseline and alternative scenarios for the EU25 based on individual MS BSE test positives data, the number of animals tested between 2001 and 2011, and the standing population. When developing the generic model to cover all EU25 MSs, a number of assumptions were made which need to be highlighted, including selected distributions within the calculations and the use of average prevalences for those countries who have reported no, or few, cases post 2001.