Will bovine spongiform encephalopathy transmit to humans?BMJ 1995; 311 doi: https://doi.org/10.1136/bmj.311.7017.1415a (Published 25 November 1995) Cite this as: BMJ 1995;311:1415
- Jeffrey W Almond, professora
- aSchool of Animal and Microbial Sciences, University of Reading, Reading RG6 2AH
The possibility that bovine spongiform encephalopathy might transmit to humans has been acknowledged since the disease was first recognised in British cattle. Indeed, one of the control measures introduced in 1989--that of removing certain offals from bovine carcasses--was designed to minimise the risk of transmission to humans. The proscribed offals were those which were known to contain high levels of infectivity in sheep infected with scrapie and in mouse models of transmissible spongiform encephalopathies, there being (at that time) no information about the tissue distribution and levels of infectivity of bovine spongiform encephalopathy in bovine tissues at the various stages of the disease. Reassurance was provided by the observation that transmissible spongiform encephalopathies from other animals showed no evidence of transmission to humans. This is in spite of the fact that, for sheep scrapie at least, there is widespread exposure to, and consumption of, infected animals. Nevertheless, transmissible spongiform encephalopathies can transmit from one species to another, and for any given donor species there is no way of predicting which recipient species will be susceptible.
How can the risk to humans be assessed in light of current knowledge? One question is whether bovine spongiform …