A CASE of atypical bovine spongiform encephalopathy (BSE) has been discovered in a six-year-old beef cow in the US state of Florida, US media sources are reporting this morning.

The US Department of Agriculture is yet to issue an official statement on the detection, but Reuters and other US agencies and media are claiming the USDA confirmed the case yesterday.

The animal tested positive for atypical H-type BSE on August 26 at a Colorado veterinary diagnostic laboratory, as part of routine surveillance of cattle that are found to be unfit for slaughter, USDA told Reuters.

The cow was destroyed, and no body parts entered the food chain.

“At no time did the animal present a risk to the food supply, or to human health in the United States,” USDA said in a statement.

Atypical BSE occurs rarely and spontaneously in cattle, so there is no association with contaminated feed or ingestion of infected materials, a spokeswoman for the US Animal and Plant Health Inspection Service said.

As part of the investigation, officials will look at offspring of the affected animal, as well as animals that were born and raised in the same location at the same time as the affected animal, Reuters was told.

There are two forms of BSE: atypical and classic. Yesterday’s discovery is the sixth detection of BSE in the US. Of the five previous US cases, the first, found in Washington State in 2003, was a case of classical BSE from a cow imported from Canada.

The other five subsequent cases have been atypical (H- or L-type) BSE, which occur spontaneously. They were discovered in Texas in 2005, Alabama in 2006, California in 2012, and Alabama in 2017.

More recent cases of atypical BSE in the US have aroused little or no concern among consumer groups, the meat trade, o export customers.

Ireland last year also reported an atypical case of BSE.

Australia has never detected a case of BSE, but the possibility exists that a spontaneous atypical form of the disease may some day be found in an animal, as it has occasionally in the US. Australia, like the US, maintains a rigorous targeted surveillance and testing process for both at-risk animals and random cattle at slaughter.

First detected in Britain in the 1980s, classic BSE decimated beef herds in parts of Europe and later, Japan. The first classic case of BSE discovered in the US dramatically disrupted beef trade flows into key export markets for some years.

Classic BSE is linked to the brain-wasting Creutzfeldt-Jakob disease in humans. In 1997, a worldwide ban was instituted on the use of cattle feed containing brain or spinal tissue, which can result in transmission of the disease. Australia had imposed such a ban decades earlier, leading to the OIE recognising Australia as one of the lowest risk countries in the world for BSE.