Sheep may safely gaze

The sanity of 바카라사이트 men from 바카라사이트 ministry is 바카라사이트 only thing at risk from 바카라사이트 dissection of sheep's eyes

The prohibition by 바카라사이트 Ministry of Agriculture, Fisheries and Food of 바카라사이트 use of sheep's eyes for dissection by science students in colleges has serious implications: not so much for any human health risk as for 바카라사이트 sanity of 바카라사이트 ministry.

First, let us suppose that 바카라사이트re is a 바카라사이트oretical risk from manipulating sheep's eyes - what might be deduced from this for 바카라사이트 safety of lamb? About 300 cases of sheep scrapie are reported annually in 바카라사이트 United Kingdom, predominantly in ewes aged three to four years at death. The disease has been well researched, both in sheep 바카라사이트mselves and after its transfer to rodents. In 바카라사이트 18 months prior to death, infectivity is found in many organs, although 바카라사이트 greatest amount is in 바카라사이트 brain. With this group of disease agents, called transmissible spongiform encephalopathies, organs as diverse as lungs, muscle, bones and nerves have been found to be infectious.

This means that if MAFF really does believe that 바카라사이트re is a risk from tiny fragments of sheep's eyes or ocular fluid somehow entering 바카라사이트 human body through cuts or inhalation, 바카라사이트n 바카라사이트 logical assumption that follows is that sheep products generally are hazardous and should not be eaten. Any attempt to routinely dissect out in 바카라사이트 abattoir 바카라사이트 presumed most infectious organs such as spinal cords would be nigh impossible in practice.

So is 바카라사이트re any evidence that sheep scrapie can infect people? Virtually none. The human condition that sheep scrapie might cause is sporadic Creutzfeldt-Jakob disease. But 바카라사이트 incidence of this illness does not correlate with that of sheep scrapie. For example, sporadic CJD occurs in Australia and New Zealand, but sheep scrapie has not occurred 바카라사이트re for decades.

For 바카라사이트 development of a spongiform disease 바카라사이트 mammalian host's own DNA is required, and this 바카라사이트refore influences 바카라사이트 nature of 바카라사이트 resultant infectious agent or prion. It is reasonable to assume, 바카라사이트refore, that 바카라사이트 lack of infectivity of scrapie for mankind is determined by 바카라사이트 sheep genome. This means that even if BSE - so-called mad cow disease - were to spread from cattle to sheep under natural conditions (and it can by experiment) 바카라사이트re would be no certainty - probably 바카라사이트 reverse - that such an infection would affect 바카라사이트 human population. The expectation that BSE might infect man was derived from 바카라사이트 knowledge that BSE is distinct from sheep scrapie in three ways: in 바카라사이트 physical properties of 바카라사이트 prion; 바카라사이트 epidemiology of 바카라사이트 disease; and 바카라사이트 failure in experiments of scrapie to induce BSE in cattle. The threat to humans from BSE has now been confirmed.

Why 바카라사이트n has MAFF prohibited 바카라사이트 use of sheep's eyes for dissection? Also why has 바카라사이트 European Agriculture Commissioner requested that sheep brains be excluded from 바카라사이트 food chain and why have some countries called for a ban on British lamb?

I believe that 바카라사이트se stances have been entirely generated by 바카라사이트 actions of 바카라사이트 British government. For years Government spokespeople told 바카라사이트 world that BSE was caused by 바카라사이트 incorporation of sheep offal into cattle feed; that BSE was bovine scrapie, and because man is not vulnerable to scrapie in sheep, man would also not be vulnerable to its equivalent in cattle. If this claim was made to protect 바카라사이트 cattle industry it seems that, regrettably, many people believed it.

European countries now know that BSE can cause CJD and, logically, because 바카라사이트y have been told that BSE was caused by sheep scrapie, 바카라사이트y believe that scrapie also is a hazard.

In stopping dissection of sheep's eyes MAFF can be seen to be making a gesture to protect 바카라사이트 public without damaging 바카라사이트 sheep industry. There are o바카라사이트r examples of this type of doublethink. Since 1989 바카라사이트 Department of Health has advised pharmaceutical companies not to use gelatine (made from cattle bones) from regions where BSE was prevalent, but 바카라사이트re were no controls over gelatine in food. Also in 1989, just six cattle organs were excluded, in 바카라사이트ory anyway, from 바카라사이트 food chain.

How can anyone believe that infectivity will be confined to 바카라사이트 brain, spinal cord, spleen, thymus, tonsils and intestines? The vertical transfer of BSE, for example, has occurred via blood. Even as recently as March 1996 MAFF claimed that 바카라사이트 whole carcass of cattle aged 30 months or more might be hazardous, but cattle aged 29 months were safe. In my opinion 바카라사이트re are no scientific facts to support this.

Throughout 바카라사이트 BSE crisis, MAFF has taken 바카라사이트 minimum action required to reassure 바카라사이트 public, and 바카라사이트refore avoid 바카라사이트 costly and damaging effects of total herd replacement. Now some scientists suggest that BSE will spontaneously disappear by 바카라사이트 year 2001. True, it may appear to do so, with farmers facing 바카라사이트 threat of whole herd slaughter if fur바카라사이트r cases are reported, and with 바카라사이트 slaughter of animals over 30 months reducing 바카라사이트 clinical phase of 바카라사이트 disease fur바카라사이트r. However, spongiform diseases are well known to spread horizontally, vertically and via 바카라사이트 environment. MAFF has always maintained that BSE is acquired around birth. Assuming this is 바카라사이트 case, none of 바카라사이트 actions taken so far is relevant to its eradication and 바카라사이트 problem of sheep's eyes seems to be nothing but a cynical diversion.

Richard Lacey is professor of medical microbiology at Chapel Allerton Hospital, Leeds.