Lindy Kato (Writer)

Encyclopaedia Britannica

I have been thinking about mad cows. It was the big thing when I left the UK in 1987. The first diagnosed cow was in 1986, but the suspicious death of a cow in Sussex in 1984 was later confirmed as Bovine Spongiform Encephalopathy(BSE a.k.a mad cows). It is likely to have been around fifty years now since the infection was seeded because the incubation period is long (years in cattle) and can be very long (decades in humans).

The source of the infection was most likely an animal feed product of meat and bone meal (MBM). The likely diseased ingredient being rendered down scrapie infected sheep included in the meal which was then fed to cattle.

Agriculture minister John Gummer tried to persuade his four-year-old daughter to eat a beefburger on live TV in 1990. She sensibly refused so he took a bite. The point was to demonstrate to the ordinary citizen that British beef was safe. As far as I am aware he had a long and healthy life. Less fortunate was a family friend of his who was diagnosed with the new variant Creutzfeldt-Jakob disease (vCJD) when she was 21 and died in 2007. This is the variation of mad cows when it appears in people. It is on the top of my worst ways to die although hopefully less likely than the other contenders.

As soon as I saw a TV clip where a farmer mentioning his cat had collapsed in 1986, I realised it would be transmissible to other species. Just as cats were the first victims in Minamata Bay (Japan) from methyl-mercury poisoning which would go on to injure well over two thousand people. Because cats are frequently fed offal or fish gut. The link between mad cows and humans wasn’t made (or made public) until 1996. Funny I guessed a decade earlier that it would be able to jump species. I don’t think it takes a genius to work it out.

The Transmissible Spongiform Encephalopathies (TSEs) turned out to be a previously misunderstood infectious disorder (as well as genetic – see later) transmitted by a misfolded protein, now called a prion. Which had already been suggested by Stanley Prusiner who was thought to be nuts (cracked pots let in the light). He won a Nobel Prize in 1997 for his work. The misshapen proteins multiply in the brain and form clumps, stuffing up usual brain processes. All the TSEs are neurodegenerative and fatal. There is no treatment.

This diagram comes from the Mayo Clinic for medical and educational research (thank you).

Prions can withstand being burnt and turned to ash and additionally are unaffected by sterilising chemicals. The ash remains infectious and surgical equipment used on a sufferer of any TSE must be destroyed. Iatrogenic CJD (iCJD) is the name given to infection caused by ‘treatment’ whether it be dental, surgical, injection, infected blood, donated body parts etc. Burning the cattle simply spread ash far and wide, 4.4 million cows were slaughtered and burnt.

Aside from the ethics of feeding downed sheep to cattle, this is far from the first time a spongiform encephalopathy has spread through dietary means. One of the people my Sweetheart worked for died from Kuru, as did his wife. This occurred after eating human brain in Papua New Guinea. They wouldn’t have known what they were eating, it would likely have been the brain of a warrior and served to them as esteemed guests. They would politely eat whatever was served. It used to be a common funeral ritual to eat the brain of the dead person (now banned). It too, is a horrible way to die.

Vegans needn’t feel safe, transmission has been known from vegetables grown in soil supplemented by blood and bone, a standard plant feed. Another thing I need to make clear is that we need prions (see later), it is only the misfolded prion proteins that cause the problems.

To be clear, vCJD is caused by contaminated meat, meat products and plant supplements deriving from bovine sources, but Creutzfeldt-Jakob disease (CJD) has been around a lot longer (first described in 1920) and appears to occur spontaneously (i.e. no one knows how) with a small (less than 10%) being inherited genetically.

Fatal familial insomnia (FFI) is caused by a mutation in the gene that makes the prion protein and can be inherited or the result of a new genetic mutation. It is very rare and mostly manifests after puberty or even much later but the deal is the same, you don’t sleep, go mad and die. The failure to sleep (drug resistant insomnia) is the basic difference.

Gerstmann–Sträussler–Scheinker syndrome (GSS) is exclusively heritable and found in only a few families all over the world. It could be more common as very rare diseases tend to be attributed to more common causes and so are underreported. It is classified as a TSE because it is caused by the same prion, is fatal and there is no treatment.

It sounds like April Fools Day and I am full of gloom. I’m not because it was thought at one point that there would be huge numbers of cases of vCJD in the UK and it hasn’t happened. The latest information from the Edinburgh surveillance website https://cjd.ed.ac.uk/surveillance/data-and-reports suggests confirmed vCJD deaths total 123 with another 55 probable (and no one currently known to be infected with vCJD). There are 20 possible cases of something known as Variably Protease-Sensitive Prionopathy which may be linked and is likely under-reported because the average age of onset in 70 years and it causes ataxia and dementia. Plus there are 98 known cases of iCJD (five from pre 1990 so may not be bovine related).

Whether an avalanche of cases will happen because the incubation period can be so long, I don’t know, but New Zealand has recently removed the rule that prevented anyone who has been in the UK prior to 1986 from giving blood. Yes, TSEs result in an irreversible and agonising decline in cognitive capacity ending in death. But at least we are aware. Normal prion formation may be critical to brain function, there has been suggestion that they are involved in memory. They have been found to boost survival in yeast. I know you aren’t a yeast so it will be of small comfort.

I think the take home message here is that cows should eat grass.