Researchers now believe they know the cause of mad cow disease, offering insight into how farmers and consumers can take precautionary measures to avoid its re-emergence.
When the disease first reared its head in the United Kingdom in the 1980s, researcher presented several hypotheses surrounding the cause of bovine spongiform encephalopathy, a neurodegenerative disease dubbed ‘mad cow disease’. None of which were verified.
Belonging to a family of ailments involving misfolding proteins know as prions, the mad cow disease has a cousin that also effect sheep, scrapie. The Creutzfeldt-Jakob disease, which effects humans, also belongs to the same family as mad cow disease.
By injecting mice with a scrapie variant, researchers were able to produce the prion of bovine origin following genetic manipulation.
This finding allowed them to demonstrate not only that the illness had the ability to transfer from one species to another, but that the transmuted mice developed mad cow disease.
The genetically modified mice were “a very good model, which works well in terms of knowing what would happen if one exposed cows to those prions,” Olivier Andreoletti, a researcher with the French National Institute for Agronomic Research (INRA), which led the study.
“These results are explained by the presence of quantities of classic mad cow disease” which are present in natural form in the scrapie variant prions injected, INRA stated.
“For the first time, these data bring an experimentally underpinned explanation to the appearance”
Mad cow disease then spread in cattle across Europe, North America and numerous other regions. The process aided by their consumption of foodstuffs including cereals and giblets from other cows with the disease.
Obviously, contact with the products from the infected cattle led to the disease being transferred to humans, mutating into the disease Creutzfeldt-Jakob.
After the 1990s, Europe introduced a variety of measures to counter the spread of the illness including banning animal cereals, tougher surveillance of cross-contaminations and destruction of the highest risk tissue.
“These measures are still in place—but they are very expensive, leading in some quarters to calls for their elimination and “to resume recycling of good quality proteins” Andreoletti observed.