Mary Ann's joke about eating brains is too true to be very funny.
There is a lot of concern in the UK about the risk of catching CJD from beef.
Sometime in the early 1980s, cattle food manufactures started adding processed
waste meat, including heads and offal, to cattle feeds to increase the protein
content. The agent that causes this type of disease is very resistant to heat
and is unlikely to be distroyed by cooking. As a result, either sheep scrapie
was transfered to cattle or possibly a varient that existed at a very low
level in cattle was spread to a large nunber off animals. Either way, a new
disease of cattle BSE (Bovine Spongiform Encephalopathy) popularly known as
mad cow disease, was recognised around 1986.
The disease was found to concentrated in the brain and nerve tissues of the
animal and consequently:-
Meat could no longer be used in cattle feed.
All diseased animals were to be incinerated.
The brain and various other parts were banned from human food.
The outbreak has been slow to die down and there are still about 350 new cases
per week. There was concern that BSE could produce CJD in humans but there was
no evidence that BSE could be passed to other species and the above actions kept
infected meat out of human food. Unfortunately, the disease has no obvious
symptoms for some years and cattle incubating the disease have certainly been
slaughtered for food. Recently, some zoo animals have developed a very similar
disease and it would seem that the disease is not confined to cattle.
The story has been around for amost 10 years and there has been no increase
in the incidence of CJD. However, the incubation period in humans is thought
to be up to 20 years and recently there have been several deaths of young
adults which is unusual and there have been more deaths of farmers than
would be expected. Hence CJD is headline news again.
For some reason, BSE seems to be confined to the UK so most of you have no need
to worry.
Nigel Cockle
