BSE test proposals
The test
On the 22nd December 1989 I made an application to MAFF for a grant of £10,000 over 2 years to fund the evaluation of the touch test. I was told at the beginning of 1990 that the reason that my grant application had been turned down was that there was limited funding. Within a matter of days the Minister announced that some £10 million additional funds were being made available for BSE research.
However MAFF did not want to know. Mr Ray Bradley at MAFF (MAFF's BSE research co-ordinator) told me in January 1990 that BSE was like scrapie in sheep. He said that there was no risk to humans. It was a dead-end disease as far as cattle were concerned. He told me that my test was very sensitive and that the Minister was fully aware that affected cattle were going through the abattoirs. He told me that my test was too sensitive and that the Minister did not want my rubber stamp merely to prove that they were affected. When I suggested that we might do the study privately for our own knowledge to find out what percentage of animals were infected if any, he told me that results eventually would become public knowledge and this would cause a big headache for MAFF and the Government.
Under current rules, all cattle up to thirty months of age - except those showing obvious signs of BSE - are deemed fit for human consumption. Of those animals deemed fit, however, some will be harbouring BSE without showing any outward symptoms of the disease. Currently, the Ministry of Agriculture Food and Fisheries (MAFF) has no live test to determine whether or not those are diseased. Hence, the public will never be protected against BSE, nor will BSE ever be eradicated, unless all cattle are subjected to a live BSE test as a practical way of distinguishing healthy animals from diseased ones.
I have developed such a simple BSE test - actually, of cattle urine. Time and again, however, MAFF and serial Secretaries of State for Agriculture have refused to give my test a formal trial.
I am prepared to offer the urine test - free - to whichever government body or agency will guarantee to oversee its proper use. Mr Bell publically gave the impression that he was helping without finecial rewards for himself
Although the science of BSE is complicated, I will try to describe in layman's terms - here, below - the background to the urine test for BSE.
Histopathological studies
Scrapie - a sheep disease roughly equivalent to BSE - is diagnosed when spongy changes are found in sheep brain sections examined by microscope. Typically, vacuoles - holes - occur in neurons of the central nervous system (CNS), whilst apparently no other changes are seen in the animal's other organs, although they also carry the infective agent. The extent of these holes in the CNS is variable. In naturally occurring scrapie, out on the farm, the holes are less numerous compared to an artificial, experimentally induced infection. These holes - or "spongiform" appearance have become the most well recognised diagnostic hallmarks of scrapie, BSE and CJD.
Relationship of clinical symptoms (while the animal is still alive) and vacuoles, or holes (seen at post-mortem)
Identifying preclinical cases of BSE is one of the main priorities if we are ever to clean the national herd of this disease. BSE, like other spongiform diseases, has a very long, symptom-free incubation period followed by a protracted clinical course, with increasingly severe symptoms occurring over months or even years. Spongiform holes only appear, however, when clinical symptoms in the animal are apparent. The two coincide.
But there is another tell-tale sign of disease even before the first symptoms appear. For over 10 years it has been known - from chronological studies of experimental scrapie and Creutzfeldt-Jakob disease – that so-called tubulofilamentous particles will appear in the brain before any spongy holes or outward symptoms have appeared. (See published papers – H Narang, Virus Research, 9: 293-306,1989; PP Liberski et al, Acta Neuropathol 79:349-354, 1990)
Cattle over 30 months old may or may not be infected. However, it is now the rule that cattle over 30 months old cannot be used for human or animal consumption. But except for physical, visual examination, the Ministry of Agriculture Fisheries and Food (MAFF) have no diagnostic method to detect infected but symptom free animals. In one MAFF experiment, in order to establish co-relation of brain changes with clinical symptoms, BSE-inoculated cattle were killed at a regular interval of 3 months. These brains were then examined by MAFF's standard histopathological method, and spongiform changes were only seen in the brains of cattle that had been killed after clinical signs had appeared. In other words, MAFF's standard post-mortem test for BSE - the only one they have - cannot possibly be used to identify live, symptom-free animals which are incubating BSE.
The development of a "touch technique"
Narang et al (1987) developed a "touch technique" which could reveal yet another tell-tale, pre-symptom sign of disease - so-called scrapie associated fibrils (SAF)/ or nemavirus particles. (This method has been used for humans [H Narang, R H Perry. Lancet, 335:663-664, 1990], but the same applies to BSE in cattle). Further, a chronological study of scrapie-infected hamster brains revealed that NVP and SAF are seen 10 days post-inoculation from the inoculated right side of the brain, and from 18 days post-inoculation from both sides of the brain. In a random study, cow brains from apparently healthy cattle over four years old were collected from a local abattoir. Examination by this "touch technique" revealed 29% of the animals were positive for SAF/nemavirus. They were harbouring BSE.
MAFF, in a comparative study, compared my touch-technique with their standard centrifugal extraction technique for detecting SAF, using scrapie sheep brains that were showing clinical disease (Stack et al, Research in Veterinary Science, 59:247-254, 1995). The authors suggested that my touch technique was no better than their centrifugal extraction technique.
But the authors failed to acknowledge that the touch technique was not only a far simpler, easier and quicker means of diagnosing BSE or CJD. With less handling of infective tissue involved, it also minimises the risk of exposure to those doing the work. Most important, however, is that the touch technique works when the animals are not showing any clinical symptoms, and are less than a quarter of the way into BSE's incubation period.
At the peak of the BSE epidemic, MAFF did a comparative study using scrapie-infected sheep brains. Although common scrapie is in many ways similar to BSE, it is not at all identical. BSE kills cattle and humans, for example, but common scrapie doesn't. So ask yourself a simple question. Why - when cattle were dying of BSE in their tens of thousands - didn't MAFF use BSE brains for their comparative study?
All that aside, the simple urine test I developed for BSE remains on offer both for official validation and for general, urgent use in combating BSE and its continuing threat to humans. (For other tests, which can be used, please see the main web site. What is involved to this test, ask a Biochemist).