Public summary of the meeting on
20th September 1999

The Spongiform Encephalopathy Advisory Committee met at the offices of the Ministry of Agriculture, Fisheries and Food, Tolworth on the 20th September 1999. This was Professor Peter Smith's first meeting as Acting Chairman of the Committee and Professor Ian McConnell's first meeting following his recent appointment to the Committee.

The Committee conducted its regular review of research findings and epidemiological information on BSE and vCJD. 

The Committee noted that the total number of confirmed vCJD cases in the UK had risen to 44 (since the meeting a further three cases have been confirmed). The Committee was informed that the CJD Surveillance Unit had undertaken a further analysis of the geographical distribution of vCJD cases the results of which had confirmed earlier analyses that there was no evidence of any geographical clustering of cases.

At the request of the Department of Health (DH) the Committee considered whether the advice it had given in June with regard to contact lenses should also apply to trial or diagnostic contact lens fitting sets and ophthalmic devices that come into contact with the eye. After careful consideration the Committee provided advice to Ministers. 

The Committee reviewed the action being taken in the UK to reduce the theoretical risk of transmitting vCJD through blood and blood products. This review was undertaken following the recent decision of the USA and Canadian authorities not to accept blood and plasma donations from people who had spent six months or more cumulatively in the UK between 1980 and 1996 and the results of recently published research. The Committee were pleased to note that following their earlier advice and that of the Committee on Safety of Medicines, all licensed blood products are now manufactured using non-UK plasma, and all blood collected in the UK will be leucodepleted from 1 November 1999. Having considered the available evidence, the Committee concluded that no further steps were currently necessary to ensure the safety of UK blood.

The Committee considered a report on action being taken by the DH to reduce the risks of iatrogenic transmission of vCJD through surgical procedures. The Committee confirmed its earlier view that rigorous implementation of washing, decontamination and general hygiene procedures were key measures in minimising the risk of infection. They noted the comprehensive package of guidance recently issued by DH to the NHS and independent sector reminding them of the action they should be taking with regard to the cleaning and decontamination of instruments and that an audit was planned to verify compliance with this guidance.

The Committee was provided with updated information from mathematical risk assessment models for assessing the possible risk of transmission of vCJD from contaminated instruments. They noted that the huge uncertainty about the possible number of people who might be incubating vCJD remained a key factor in determining conclusions. The Committee recommended that a group of experts be convened to review the model and report back to the Committee. 

The Committee concluded that although the theoretical risk of iatrogenic transmission could depend on a number of factors, it was likely to be greatest from operations involving central nervous system and ophthalmic tissue, followed by lymphoid tissue. The Committee considered that, wherever practicable, the use of disposable instruments for such surgery was to be encouraged. Tonsillectomies were identified as a discrete operation where specific practical steps might readily be taken and the Committee noted that DH was examining the feasibility of the use of disposable tonsillectomy instruments. The results of this assessment were expected shortly.

On research being undertaken into vCJD, the Committee accepted that most of the major areas were being addressed. The Committee recognised that it would be some time before many of these projects produced results but that these research findings would increase considerably understanding and knowledge of the disease. The Committee did however reiterate its view that the search for a diagnostic test using blood should be a key priority and recommended that the DH explore with urgency all possible means of securing such a test.

The Committee conducted their usual review of BSE research and epidemiology. The BSE epidemic in cattle continues to decline although the rate of decline has slowed as the tail of the epidemic is reached. The Committee noted that it was expected that updated epidemiological analyses of the epidemic would be available for its meeting in November. The Committee agreed to postpone discussion of the Over Thirty Month rule until that meeting so that it could take these analyses into account. 

In April 1999 the Committee published a report from its subgroup on research and surveillance for TSEs in sheep. Members considered an interim report on progress and noted the complexities associated with some of the recommended research. The Committee continued to accord very high priority to research on the possible presence of BSE in sheep. They requested a position paper to enable them to identify problems and track progress. They also agreed that a subgroup should consider the objectives and options for further surveys of TSEs in sheep.

Members noted a proposal for a further study of maternal transmission of BSE in cattle. They deferred making a recommendation on the proposal until the November meeting when it could be considered in the light of fresh epidemiological analysis. 

The next meeting of the Committee will be held on the 29th November 1999.

SEAC
October 1999