A Department of Agriculture expert has predicted that BSE should be virtually eliminated by the end of 2005. The disease has cost the Irish taxpayer tens of millions of pounds over the last 10 years.
Mr David Lynch, a senior veterinary expert with the Department of Agriculture, told a press briefing that because of controls being operated by the Department, no animal born after January 1st, 1998, had been exposed to the disease.
Increased levels of testing for the disease meant the number of cases this year should peak. Next year there should be a slight decline in cases and there should be an accelerated decline in the following years.
Both Mr Lynch and Ms Hazel Sheridan, an epidemiologist in the Department, agreed that the oldest animal identified with BSE was 19 years, and "stray" cases would continue to be found.
"However, we are predicting that there should be a major decline in the number of cases, as the majority of cases of BSE in the Irish herd have been diagnosed in five and six-year-old cattle," said Ms Sheridan.
She said all cases diagnosed to date involved cattle born prior to 1997 and up until Friday last there had been 660 cases of BSE identified in the national herd since 1989.
Of these, she said, 627 had been identified by passive surveillance, 17 identified by active surveillance when sick animals and casualties were tested, and 16 cases found in follow-up tests when animals were being slaughtered on farms where the disease was identified.
She said the youngest Irish animal diagnosed with BSE had been 42 months old and the oldest 15 years, and for that reason she suspected a small number of cows infected in the early 1990s would be coming through the system for some years to come.
There was also a seasonal pattern to the disease, with most cases showing up in the winter.
Ireland had a very low incidence risk, with 16.9 cases per million animals aged over 24 months.
Mr Lynch outlined the controls which had been put in place since 1989 and said the total elimination of any possible contamination of animal feed from infected meat-and-bone meal from January 1998 should lead to an accelerated decline in the number of cases from next year on.
Dr Michael Gunn of the Department dealt with the question of the burial of infected animals on farms, a practice which had continued until last year. Now the carcasses were frozen until they could be incinerated, he said.
British research showed the likelihood of the most exposed person ingesting sufficient material to cause infection in one year from a landfill burial site where infected carcasses had been buried ranged from one in 10,000 million to one in one million years.
The risk from waste water from a rendering plant where infected animals were disposed of showed that the most exposed person ingesting in one year sufficient material to cause infection was in the order of one in a billion.
The secretary general of the Department, Mr John Malone, said most local authorities had asked the Department to locate the carcasses of BSE-infected animals which were buried on farms so they could be removed.
BSE, he said, had cost the State tens of millions of pounds in compensation, support to renderers and payment for the storage of meat-and-bone meal, which cannot be fed to farm animals in the EU.