300,000 mad French cows since the 1980's

Jul 3 2004

According to new French research reported in le figaro more than 300,000 French cows would have been infected by the agent BSE (Bovine Spongiform Encephalopathy ) since the 1980's. This contradicts official government figures of only 923 bovine infections since the dies ease was officially confirmed present in France in 1991.

These new figures call into question the French government's capacity to supervise the animal disease and has highlighted weaknesses in the overall management of the epidemic.

The research has been published in the Review of Veterinary Research, by Virginia Supervie and Domenica Costagliola, of Inserm.

The BSE epidemic in the United Kingdom was discovered in 1986. BSE is thought to have spread by the practice of feeding cattle meat and bone meal, a high-protein substance obtained from the remnants of butchered animals. This practice allowed the accumulation of prions over many generations. The use of meat and bone meal as a protein supplement in cattle feed was widespread in Europe prior to about 1987. Soybean meal is the primary plant-based protein supplement fed to cattle. However, soybeans do not grow well in Europe, so cattle raisers throughout Europe turned to the less expensive animal byproduct feeds as an alternative.

Of the 152 human cases so far, 143 occurred in the United Kingdom, 6 in France, and one in Italy. Three cases of variant Creutzfeldt-Jakob Disease occurred in people who had lived in or visited Britain--one each in Ireland, Canada and the United States. There is also some concern about those who work with (and therefore inhale) cattle meat and bone meal, such as horticulturists who use it as fertilizer.

Variant Creutzfeldt-Jakob Disease (vCJD) is distinguished from the classical type (Creutzfeldt-Jakob Disease) by its early onset (usually in the 20s) and a predominance of psychiatric and sensory symptoms. The prions in this form are thought to be transmitted by consuming the meat of bovines with so-called mad cow disease (Bovine Spongiform Encephalopathy), although there is no definite proof of this association as yet. However over 95% of identified cases of vCJD are in Britain.

BSE is a chronic progressive degenerative disease affecting the central nervous system of cattle. There is no treatment, and affected cattle die. BSE is classified as a transmissible spongiform encephalopathy (TSE). The causative agent for BSE has not been determined. Some believe it is a "slow virus" or a "virino" while others believe it is a "prion" (an aberrant form of a normal prion protein) that causes the normal protein to conform to its aberrant shape, which leads to a cascade of abnormal proteins accumulating in brain cells. The accumulation of protein plaques causes cell death and leaves holes in the brain giving a "sponge-like" appearance. The etiologic agent is extremely resistant to destruction.