Sacred disease of our times: failure of the infectious disease model of spongiform encephalopathy.

BACKGROUND Public health and agricultural policy attempts to keep bovine spongiform encephalopathy out of North America using infectious disease containment policies. Inconsistencies of the infectious disease model as it applies to the spongiform encephalopathies may result in failure of these policies. METHODS Review of historical, political and scientific literature to determine the appropriate disease model of spongiform encephalopathy. PRINCIPAL FINDINGS Spongiform encephalopathy has always occurred sporadically in man and other animals. Hippocrates may have described it in goats and cattle. Transmission of spongiform encephalopathy between individuals is too uncommon for it to be usefully considered an infection. Spongiform encephalopathy is a somatic disorder whose dissemination within a host or transmission between individuals is more like cancer than infectious disease. Spongiform encephalopathy transmission within a species is facilitated in comparison to transmission between species so that cannibalism may amplify the prevalence of the disease. CONCLUSION Agricultural policy should be directed toward an absolute prohibition on occult cannibalism and away from surveillance, quarantine and slaughter, the principal measures of infectious disease containment used to control bovine spongiform encephalopathy.