BSE: Science & research - Tests for detecting TSE infection in live animals
There is currently no approved technique to diagnose BSE and other TSEs in animals while they are alive.
Aims
- To develop a live animal (ante-mortem) diagnostic test for scrapie and BSE in affected sheep before the appearance of clinical disease.
- To develop a cost-effective method for screening large numbers of sheep.
- To develop an ante-mortem diagnostic test for BSE in affected cattle prior to the appearance of clinical disease.
Development of live animal TSE tests that detects PrPSc
Research is being funded in the following areas:
- Live test for sheep based on using lymphoid tissue
- Blood as the basis of a live test
- Implementing a live test
Live test for sheep based on using lymphoid tissue
The recto-anal mucosa associated lymphoid tissue (RAMALT) is abundant and readily accessible for biopsy. Through testing a relatively large number of sheep naturally and experimentally exposed to scrapie, it was shown that abnormal prion protein (PrPSc) could be reliably detected in the RAMALT of sheep clinically affected with scrapie (project SE1788). The RAMALT test shows promise to be used for ante-mortem diagnosis of preclinical cases of scrapie. It will, however, only be useful where PrPSc is present in peripheral tissues.
Blood as the basis of a live test
It is known that BSE and scrapie can be transmitted by blood transfusion from sheep infected with the TSE to other sheep (Hunter, N et al. (2002) J. Gen. Virol. 83:2897-2905).
Defra-funded research is investigating the following areas:
- Discovering which blood fractions (e.g. cells, serum, plasma) are infectious.
- Identifying at what stage of the disease TSEs are detectable in the blood.
- Applications of existing assays and new experimental techniques for PrPSc detection in blood. (Projects SE1778, SE1780, SE1793, SE2004, SE2006, SE2008, SE2010, SE2011).
Implementing a live test
As well as the laboratory work required to develop a live test, work on how to implement the use of such a test is also important. Two projects (SE0249 & SE0250) are establishing models to explore how a rapid live animal test could be applied to control classical scrapie in affected flocks and to undertake a cost/benefit analysis of its use.
Links to other information
Page last modified: 7 March, 2008