Mad cow disease in the UK: What is BSE and what are the symptoms?

The Welsh government has confirmed a dead cow in Wales has been found with the disease

A dead cow has been found to carry “mad cow disease” in Wales, with authorities claiming the meat had not entered the human food chain and there was no risk to public health.

What is mad cow disease?

Medically referred to as Bovine spongiform encephalopathy (BSE), “mad cow disease” is a neurodegenerative disease that can mutate and spread to humans. This strain is known as Variant Creutzfeldt-Jakob disease (vCJD).

When did the disease first appear in the UK?

The first confirmed case in Britain was 1986. However, the disease is notoriously hard to track as its incubation period can be anything from a few months to eight years.

What causes the disease?

It is caused by a deficient protein called a prion. Although there is still huge discussion within the scientific community in the origin of the disease, a British and Irish inquiry into the outbreak concluded it had been caused in the UK by feeding cattle the remains of infected cows.

How dangerous is it to humans?

There have been 177 cases to date of the human strain of mad cow disease in the UK. The last was in 2012.

How do humans catch it?

According to the World Health Organisation (WHO) vCJD is most frequently caught by eating beef infected with BSE. There have been only four cases globally of infection by blood transfusion.

What are the symptoms?

Humans – WHO notes patients usually experience “depression, apathy or anxiety”. They also report victims have difficulty walking and controlling their limbs. By the time of death victims are “completely immobile and mute.”

Animals – Cattle have generally been seen to become increasingly aggressive, as their nervous system deteriorates and they lose control of movement. Their milk production also drops, with some showing signs of anorexia and lethargy.

When was the last outbreak?

The last major outbreak was in 1992.

What was the cost of the last outbreak?

An estimated 180,000 cattle were affected and killed. 4.4 million cows were killed. 156 people died in the 1990s as a result of contracting the variant of BSE. To date, that number has risen to 177.

During the outbreak in the 1990s, the domestic sales of beef fell by 40 per cent with household consumption down a quarter on the previous year. The cost of beef also dramatically fell. The overseas market was crippled by an EU ban – only lifted in 2006.

Financially the cost was estimated between £740 million and £980 million to the UK economy.