US records 7th-ever case of mad cow disease in South Carolina but onward transmission ‘unlikely’

America has discovered its seventh-ever case of mad cow disease at a South Carolina slaughterhouse, health officials say.

The five-year-old cow was diagnosed with the disease at the factory after she was deemed ‘unfit’ for slaughter.

The US Department of Agriculture said the animal did not enter the country’s beef supply and officials are not concerned about further transmission.

The disease, technically called bovine spongiform encephalopathy, causes lesions on the brains of animals, giving them a spongy appearance and causing aggression and movement problems. It is always fatal.

People who eat meat from infected livestock can also become infected with the disease, which causes epileptic seizures and is fatal in seven to 10 patients. Four people in the US have developed the disease so far, all of whom have died.

The case is the seventh ever in the US (US cases in orange) and the first since 2018

Health officials are on high alert about mad cow disease, as it is almost always fatal to humans.

Millions of cattle had to be culled in the UK in the 1980s and 1990s when they developed the disease after eating feed containing ground meat and bones from cattle that had the disease.

The disease was also discovered in France, Germany, Italy and a host of other European countries, but it wasn’t picked up in the United States until 2003, when it was discovered in a cow imported from Canada.

Mad cow disease is caused by a misfolded protein in the brain – called a prion – that disrupts communication between cells and leads to the symptoms.

Animals can pick up this protein by eating the flesh of others who have the disease, the classic form of the disease, or it can arise spontaneously when a mutation causes the protein to misfold in them, the atypical form.

It can take years for animals with the atypical form to show symptoms.

The South Carolina cow was diagnosed with the atypical form of the disease.

It was tested after officials deemed the animal ‘unfit’ for slaughter, likely because it showed warning signs of the disease.

The animal also carried a radio frequency tag that linked it to a herd in Tennessee.

The U.S. Department of Agriculture, which brought the matter to light, said: “This animal has never entered slaughterhouses and at no time posed a risk to the food supply or human health in the United States.”

They have not disclosed when the case was discovered or whether other animals are now being tested.

They also did not reveal the fate of the cow, although it is likely that the animal has now been euthanized and the body has been safely disposed of.

The case is the seventh ever discovered in the United States and the first to be revealed since 2018.

It is also the sixth case of the atypical form of the disease in the US, with only one case of the classic form dating back to 2003.

Experts said it was unlikely that the US would face restrictions on livestock sales domestically or internationally as a result of the diagnosis.

Simon Quilty, an analyst at Global AgriTrends in Colorado, shared ABC News that the last time a case was discovered in 2018, it had no impact on trade.

“So you can only assume that the same thing will happen this time,” he said.

The largest beef exporters from the US are Japan, South Korea, China and Mexico.

Asked if China would consider restricting beef trade given the current trade war between the nations, Mr Quilty said this was unlikely.

“According to the US-China trade agreement, they said that no ban can be placed on an atypical BSE case, should it occur,” he added.