[Model calculation to explain the BSE-incidence in Germany].

The future development of BSE-incidence in Germany is investigated using a simple epidemiological model calculation. Starting point is the development of the incidence of confirmed suspect BSE-cases in Great Britain since 1988, the hitherto known mechanisms of transmission and the measures taken to decrease the risk of transmission as well as the development of the BSE-incidence in Germany obtained from active post mortem laboratory testing of all cattle older then 24 months. The risk of transmission is characterized by the reproduction ratio of the disease. There is a shift in time between the risk of BSE transmission and the BSE incidence caused by the incubation time of more than 4 years. The observed decrease of the incidence in Germany from 2001 to 2003 is not a consequence of the measures taken at the end of 2000 to contain the disease. It can rather be explained by an import of BSE contaminated products from countries with a high BSE incidence in the years 1995/96 being used in calf feeding in Germany. From the future course of the BSE-incidence in Germany after 2003 a quantification of the recycling rate of BSE-infected material within Germany before the end of 2000 will be possible by use of the proposed model if the active surveillance is continued.