Although scientists haven't yet determined whether bovine spongiform encephalopathy (BSE) has already entered Great Britain's sheep population, laboratory studies have demonstrated that sheep can become infected through eating nervous system tissue from infected cattle. Such a finding raises an important question: If BSE was in fact transmitted to British sheep flocks through contaminated feed supplements, what risk does it pose to human health?
To address this question, researchers at Imperial College in London have developed and tested a mathematical model to estimate possible best- and worst-case scenarios for the human impact of BSE in sheep (Nature. 2002;415:420-424). Their analysis shows that if BSE entered the sheep population in the past and some spread occurred, then sheep BSE would pose a greater current health risk to humans than BSE in cattle—a difference largely due to the more stringent controls in place to prevent exposure to cattle BSE.
Stephenson J. "Mad Sheep" Disease?. JAMA. 2002;287(6):706. doi:10.1001/jama.287.6.706-JWM20002-3-1