BSE: Science & research - The persistence of TSEs in the environment
It is known that TSE infectivity is resistant to heat and other processes which normally inactivate infectious agents. Therefore it is important to determine whether TSE infectivity persists in the environment. Recent studies from overseas have suggested disease-associated prion protein adheres to soil minerals and remains infectious, even after a number of years.
How could TSE infectivity enter the environment?
Prion infectivity may enter soil environments via shedding from diseased animals or decomposition of infected carcasses.
- Research is underway to investigate the infectivity of tissues and fluids produced during lambing in sheep and also faeces, urine and other secreted fluids in animals infected with TSEs (projects SE1856 & SE1859);
- Ongoing research looking at the transmission of scrapie within a flock has shown that exposure to contaminated pasture alone, without any direct animal to animal contact, appears sufficient to initiate an infection (project SE1845).
Ongoing research investigating the persistence of TSE infectivity in the environment
Two research projects are underway to investigate the environmental persistence of TSE infectivity:
- A special site has been constructed to examine the survival of TSEs in buried bovine heads and the persistence and migration of TSE infectivity within soil. During the first phase of this experiment, methods to recover disease-associated prion protein (PrPSc) from soils were developed (project SE1433);
- The second study will characterise the binding and retention of PrPSc and TSE infectivity in a range of UK soils types within a laboratory setting. Both cattle BSE and sheep scrapie are being studied and any differences between TSE strains in terms of deposition in soil and persistence of PrPSc and infectivity will be investigated (project SE1858).
Page last modified: 7 March, 2008