Abigail: seeing as we haven't seen hide nor hair of BSE for years now, and seeing as there is no obvious ramp-up in vCJD (which you'd expect from an epidemic, even a long incubation epidemic, since some people get ill faster) then I think the justified conclusion on BSE is more like "it doesn't seem to jump the species gap regardless of exposure except in incredibly rare susceptible individuals". Appalling losses? Sure, financial losses, from the panic.