Mad Cow Disease and Englishmen: Dementia of Humans—Prions: Folding Protein Transmissible Diseases

This chapter studies mad cow disease. In 1985–1986, bovine spongiform encephalopathy (BSE), or mad cow disease, was first identified in cattle of southern England, and within two years, over 1,000 instances of infected cattle surfaced in more than 200 herds. Epidemiologic investigations indicated that the addition of meat and bone meal as a protein supplement to cattle feeds was the likely source of that infection. By 1993, cases of mad cow disease peaked at over 1,000 per week. In addition to controlling the BSE epidemic in cattle, procedures were established to gauge whether this disease was a human health problem and to safeguard the population from the potential risk of BSE transmission. As a defense measure, in 1990, a national Creutzfeldt-Jakob disease (CJD) surveillance unit was established in the United Kingdom to monitor changes in the disease pattern of CJD that might indicate transmission of BSE to humans. Although CJD is the most common form of transmissible spongiform encephalopathies in humans, it is a rare disease with a uniform world incidence of about 1 case in 1 to 2 million persons per year.