THE EPIDEMIOLOGY OF BSE IN CATTLE HERDS IN GREAT-BRITAIN .2. MODEL CONSTRUCTION AND ANALYSIS OF TRANSMISSION DYNAMICS

Mathematical models that describe the key processes determining the pa ttern of the bovine spongiform encephalopathy (BSE) epidemic in Britis h cattle are derived that allow for infection from feed as well as mat ernal and direct horizontal transmission. Heterogeneous susceptibility classes are also incorporated into the analysis. Maximum likelihood m ethods are used to estimate parameters and to obtain confidence interv als from available experimental and epidemiological data. A comprehens ive sensitivity analysis of all model parameters and distributional as sumptions is presented. Additional validation is provided by fitting t he model to independent data collected in Northern Ireland, Model esti mates and predictions based on BSE case data for Great Britain and Nor thern Ireland, together with their implications, are reviewed, and fut ure research priorities discussed.