Mad Cow Disease Facts

The mad cow disease is also referred to as bovine spongiform encephalopathy (BSE). It was officially recognized as an entity or a disease, in 1986. It is speculated that at least 400,000 cattle infected with the BSE entered the human food chain, since 1980. The disease causes degeneration of the neurons present in the brain and spinal cords of the cattle.

The brains of the affected cattle appear spongy and filled with holes due to the structural changes induced by this disease. The mad cow disease spreads in humans due to the use of contaminated meat and bone of a diseased animal that is ground up into a protein supplement for animal feed.

The disease is believed to have originated from a feed containing meat from sheep with a disease called scrapie. BSE had a crippling effect on the beef industry, resulting in the ban on the import of beef and considerable loss to the beef producers and consumers. The humans too, can contract it by eating the infected meat.

The control and coordination of muscles becomes difficult in the infected cattle. This leads to difficulty in standing and walking, and therefore their movement becomes sluggish. Even though the diseased animal continues to eat normally, it starts losing weight.

A significant decrease in the production of milk can also be noticed. The disease also induces changes in the behavior of the affected cattle.

When this disease infects humans, it is known as variant Creutzfeldt-Jakob disease (vCJD). The symptoms are anxiety, insomnia, and memory loss. All these symptoms may affect an individual's normal life.

The affected person may also exhibit behavioral disorder, which may culminate and cause fatigue, and in extreme cases, even death. It causes slow dementia, especially in people who are 50-70 years old. In humans, the disease may take as long as 40 years to show its symptoms.

Let us take a look at some interesting facts make us aware of the ground realities about the disease, and the efforts put in by the government and the researchers to reduce its threat to human life.

• The first case of the mad cow disease occurred in the United Kingdom, in 1984, when a cow died soon after it developed strange symptoms. This was followed by more mysterious deaths, which lead to scientific research to find the exact cause. Finally, in November, 1986, the British scientists made their first diagnosis of BSE.

• BSE is not caused by an invasive microorganism, but because of a mutated protein called prion. This protein affects the nervous system of a mammal and results in the deterioration of brain tissue.

• It can spread when healthy animals ingest tainted tissues from other animals carrying this disease.

• In this disease, the consumed mutated prion causes deformation of cellular prion proteins present in the brain cells. This leads to a chain of reaction, wherein the normal prion protein is deformed. The deformed prion protein comes together to form a plaque fiber in the brain.

• A change in British law, permitting the sterilization of the meat and bone to be added to the cattle feed at a lower temperature, also contributed to the spread of the disease.
• The disease spreads in humans when one consumes a nerve tissue from the spine or brain of an infected cow.

• It is estimated that the chances of contracting the vCJD is only one person per million.
• Since 1986, after the first reported case, at least 200 people have lost their lives to the vCJD.
• In the United States, there is no report of the variant Creutzfeldt-Jakob disease affecting humans.

• According to the CDC, 3 cases of BSE were reported in the United States.
• In the United Kingdom, there were 184,500 cases of BSE between 1993 and 2010. The numbers have dropped from 1,443 in 2000, to 225 in 2005.

• In April 2012, the 4th case of BSE was confirmed in California by United States Department of Agriculture (USDA).
• As of 2015, single cases of BSE were reported in Canada, Ireland, Norway and Slovenia and two in Britain.
• An isolated case of BSE was reported in Scotland in October, 2018.

It is quite normal to be worried about the risk posed by this disease; however, it must be noted that there are no cases of the mad cow disease in Australia and New Zealand. This is because the cattle in these countries feed on grass. Their feed is not supplemented with proteins like in Europe.

In the aftermath, most of the countries have come up with stricter laws regarding what goes into the animal feed. The calamities caused by this disease can be successfully averted by following these laws.

Disclaimer: The mentioned particulars are for informative purposes only, and should not be used as a replacement for expert medical advice.