M03006: Bioassay of BSE infectivity in non-neural tissues by intracerebral inoculation of cattle
Wednesday 25 June 2003
This research project aims to determine the infectivity of different types of cattle tissue by whether BSE can be transmitted to cattle by injecting them with the tissues.
Background
To determine qualitatively infectivity in certain tissues, including Specified Bovine Material (SBM), of cattle infected orally with 100 grams BSE-affected brain and killed at specified times after exposure, using a within-species bioassay. This provides the most sensitive means of detection of infectivity in the tissues in order to identify public health risks from exposure to bovine tissues.
Research Approach
The study provides the most sensitive available assay of BSE infectivity in bovine tissues which form a potential human health risk or have been identified as SBM. The results will indicate qualitative differences in the use of cattle versus mice for bioassay of BSE infectivity in experimentally, orally infected cattle. They will also provide information for use in quantitative analysis of risks of human exposure to infected bovine tissues and necessity to retain restrictions on SBM entering the human food chain. To date transmissions that have occurred in the cattle are consistent with previous mouse bioassay data. Only positive control tissues (ileum and CNS) have transmitted so far.