Up to 400,000 people could be infected by a single cow with BSE entering the food chain, according to a report by an official EU scientific committee. The report, issued in Brussels, also warns that there is evidence that high-risk material from brains and spines is being used in meat products such as pates and sausages.
Ireland has just recorded its worst year for BSE cases. A record 95 cattle infected with BSE were detected during 1999, compared with 83 cases in 1998.
This is still far below the number recorded in the UK, which runs into thousands.
The report was prepared by the EU Scientific Steering Committee on human exposure risks of BSE via the food chain. It has just been released on the Internet.
It points out that it is not known what the threshold dose for infection is, or what effect repeated low doses of infected meat might have.
Its worst scenario involved a single infected animal entering the food chain, with the full carcass being processed into food products including the so-called "specified risk materials" (SRM) - the brain, spinal cord and certain internal organs. It suggested that up to 400,000 people could be exposed to infected material in such a circumstance.
"Recent evidence suggests that in countries with a reported low incidence, the actual rate of BSE infected animals entering the food chain is not nil," the report stated. "Presently available methods to prevent an infected animal entering the food chain are far from being satisfactory."
A single infected animal could contaminate up to 116 tonnes of minced meat product.
The SRM tissues presented the greatest risk to human health because they contained the highest concentration of BSE infectivity. "Intestines used from young infected animals are of particular concern since they become infectious in an early stage of the BSE incubation.
"The SSC is aware of the direct human consumption of both intestines and brain material by many population groups within the EU and now has evidence of brain and spinal material being used in common meat products such as pates and sausages."
The report takes away any comfort to be drawn by those countries such as Ireland with a relatively low BSE infection rate.
"Since there is inter-memberstate transfer of animals, cross-border trading in animal organs and marketing of offals, ingredients and processed foods into and out of most EU memberstates, it is reasonable to conclude that the risk of human exposure to BSE infectivity within any one country is not necessarily linked to the geographical burden of infectivity in the cattle within that memberstate."
It said the "ideal level" of protection of consumers from exposure to BSE infectivity is "the absence of infected animals from the human food chain." If this could not be reasonably guaranteed, the second level of protection involved "the removal of SRMs" from processing. "Failure to do so is likely to expose a large number of consumers to an unnecessary risk."
The risk of BSE-infected meat is associated with its transfer to humans in the form of variant Creutzfeld Jacob Disease. The disease is invariably fatal but so far is comparatively rare. About 50 cases have been diagnosed in the UK, including one in Northern Ireland. One has been found in the Republic.
