ACMSF 40th meeting minutes

Minutes of the 40th meeting of the Advisory Committee on the Microbiological Safety of Food held on 21 March 2001 at Skipton House, Elephant and Castle, London SE1 starting at 10.30am. Papers are available at the bottom.

ACM/MIN/40 (final)


Chairman: Professor D L Georgala

Members: Mr D Clarke
Mrs P Jefford
Professor A M Johnston
Dr M J Painter
Professor S R Palmer
Dr T A Roberts
Dr N A Simmons
Mrs B W Thomas
Dr T D Wyatt

Assessors: Mr P J R Gayford (MAFF)
Professor C H McMurray (NIDARD)
Dr R Skinner (FSA)

Secretariat: Dr J Hilton (Medical Secretary)
Mr C R Mylchreest (Administrative Secretary)
Mrs E A Stretton

Others: Dr J R Bell (FSA)
Dr J P Back (FSA)

1. Chairman's introduction

1.1 The Chairman welcomed Members to the Committee's fortieth meeting. He noted that Mr Clarke, Dr Clayton, Mr Kilsby, Dr Painter, Dr Palmer, Dr Roberts, Dr Simmons, Dr Stevens and Mrs Thomas would all be retiring from the Committee after 31 March 2001. He thanked all of the retiring Members for the tremendous contribution they had made to the work of the Committee, and its Working Groups, over the years. He was particularly grateful for the willingness they had displayed to work as part of a team and for their assistance in managing some long and difficult agendas. He offered his best wishes for their future endeavours.

1.2 In relation to his own position, Professor Georgala reported that he had accepted the invitation of the Chairman of the Food Standards Agency (FSA), Sir John Krebs, to serve for one further 3-year term from 1 April 2001.

1.3 Professor Georgala introduced Dr Jon Bell, the Food Standards Agency (FSA)'s Director of Food Safety Policy and its Deputy Chief Executive. Dr Bell explained that he was deputising for Sir John Krebs who, in view of the impending retirement of so many of the Members, had originally hoped to be present at this meeting of the Committee. In the event, a prior commitment had prevented Sir John's attendance but he was keen to attend a future meeting.

1.4 Dr Bell said that the FSA had put food safety right at the top of its agenda. The effectiveness of the Agency would be judged in part against the challenging targets it had set itself for the reduction both of foodborne disease and Salmonella, contamination of UK-produced retail chicken. Microbiological food safety was a key aspect of food safety - the current food and mouth disease crisis served as a reminder of the continuing vulnerability of the food chain to risks from microorganisms. The ACMSF was regarded by the FSA as very much a frontline source of advice. The Agency greatly valued the contribution made by ACMSF Members, and the time they gave over to Committee business, for little personal reward.

1.5 Dr Bell said that the FSA Chairman and Deputy Chair had been very interested in the outcome of the ACMSF's first open meeting on 5 December 2000. The Agency was fully committed to the principle of openness - FSA Board meetings had been held in public - and was very supportive of the steps taken by the ACMSF.

1.6 Dr Bell said that the Agency would be embarking upon a review of the interaction between the FSA and the scientific advisory committees later in the year. This did not indicate dissatisfaction with the service the committees were providing. Rather, the review was intended to examine whether the current set up was appropriate to the needs of both the Agency and the committees. Dr Bell envisaged that the ACMSF would continue to advise the FSA for many years to come.

2. Apologies for absence

2.1 Apologies for absence were received from 4 Members - Dr Clayton, Ms Lewis, Professor Smith and Dr Stevens - and one Departmental Assessor - Dr Donaghy.
3. Minutes of the 39th meeting

3.1 Members agreed ACM/MIN/39 (Revised) as a correct record of the 39th meeting.

4. Matters arising

4.1 A summary of matters arising is at Annex A to these minutes.

5. Public Health Laboratory Service presentation on LACOTS/PHLS examination of ready-to-eat (RTE) foods with added spices

5.1 The Chairman reported that Dr Sarah O¿Brien (PHLS Communicable Disease Surveillance Centre), had been due to present a paper on ready-to-eat foods to which spices had been added under this agenda item. She had also intended to present a paper under agenda item 6 updating the information presented to the Committee by the PHLS in June 2000 on the microbiological status of fresh fruit and vegetables. However, Dr O'Brien was currently heavily engaged in the investigation of a food poisoning outbreak and was thus unable to attend the meeting. She sent her apologies to Members. Professor Georgala said that agenda items 5 and 6 would therefore be deferred until a later meeting.

6. PHLS update on microbiological status of fresh fruit and vegetables

6.1 See paragraph 5.1.

7. Progress reports

Joint FSA/Scottish Executive Task Force on E. coli O157

7.1 Dr Simmons reported on meetings of the Task Force which he had attended on 12 December 2000 and 23 February 2001 on behalf of the ACMSF. A summary of his oral report is at Annex B.

FSA Conference on Mycobacterium avium subsp. paratuberculosis (MAP)

7.2 Dr Hilton reported that plans were now well advanced for the FSA MAP Conference which would be held in London Docklands on 23-24 May 2001. The Conference would consider possible measures on-farm and in dairy processing (in addition to pasteurisation) to reduce human exposure to the organism in milk. There would also be a general paper by Dr Eileen Rubery about the link between the organism and human disease, and the on-farm element would be informed by the report of the MAFF-funded review by the Scottish Agriculture College of Johne's disease. Mr Gayford reported that the final report had now been received by MAFF and would be available publicly in early April. He would be able to provide Members with copies.

Surveillance Working Group

7.3 Mr Clarke, the Chairman of the Surveillance Working Group, gave an oral summary of the report (ACM/511) of the Group's first meeting held on 13 February. Dr Skinner was invited by the Chairman to respond to the Working Group's comments, particularly in relation to the FSA chicken survey.

7.4 Dr Skinner expressed the FSA's gratitude for the Working Group's comments which had been taken into account in the further development of the protocol for the chicken survey. He reminded Members that the survey was being carried out in order to establish baseline data against which progress could be mapped towards achievement of the Agency¿s target of reducing Salmonella contamination of UK retail chicken by at least 50 per cent over the next 5 years. The Agency recognised that there were different views on the best approach to sampling and had tried to go for the most practicable option. However, to avoid criticism, it was felt that the survey needed to be representative of the raw chicken and raw chicken products actually on sale to the public. Dr Skinner said that the potential dangers of over-analysis of survey data were fully recognised. The survey would be under the close control of the FSA, and this would provide a safeguard against analysis being carried out which could not be justified in relation to the number of samples obtained. He also confirmed that the intention was for the survey to be completed, and the results published, by Summer 2001. Dr Skinner acknowledged the advantages of involving the ACMSF at an early stage. However, planning for the chicken survey had given rise to complex issues which had taken some time to resolve. Moreover, preparatory work had progressed against a tight timetable. However, the Agency had, he hoped, learned the lessons from this first engagement with the Surveillance Working Group and these were reflected in the approach adopted in relation to the proposed egg survey. In response to a further question posed during discussion, Dr Skinner confirmed that the chicken survey was being set up in such a way as to make it possible to obtain separate baselines for each of the constituent parts of the UK. He noted comments made about the importance of molecular typing in the differentiation of the different Campylobacter serotypes colonising flocks.

Ad Hoc Group on Sewage Sludge

7.5 Dr Simmons, the Chairman of the Ad Hoc Group, provided an oral report on a meeting held on 13 February. This is summarised at Annex C. It was noted in discussion that, although the Ad Hoc Group had no objections in principle to the modelling approach, concerns had been expressed about reliance upon a multiple hurdle approach particularly when it was based on a set of assumptions with which Group Members disagreed, including, for example, that organisms behaved in the same way in all soils.

Working Group on Mycobacterium bovis

7.6 Professor Johnston, the Chairman of the M. bovis Working Group, reported on the Group¿s first meeting, held on 28 February. An excellent team had been assembled to review the possible health risks associated with consumption of meat from animals with evidence of M. bovis infection, including animals with no post-mortem evidence of disease which had reacted positively or inconclusively to the tuberculin test. The Group had also been asked to advise on the adequacy of current control measures. There had been a useful first meeting at which the Group had considered material on the epidemiology of M. bovis infections in animals and humans; disease trends in cattle and humans in the UK; diagnosis of the disease in cattle; UK meat inspection procedures and the implementation of EU requirements; and the surveillance of pathology in slaughtered animals.

7.7 The Group was next scheduled to meet on 2 April. The questions which needed to be answered had been identified. It was hoped that those answers could be found in time for the Group to report to the full Committee at its 27 June meeting.

Epidemiology of Foodborne Infections Group

7.8 Dr Hilton reported on the January 2001 meeting of EFIG. The main data considered had been:

  1. animal data to September 2000 : there had been nothing dramatic to report. There had been a continuing decline in Salmonella typhimurium in cattle, although this remained the second most common serotype. The decline had not been seen in pigs where S. typhimurium was the most common serotype across the UK. There was a continuing decline in S. enteritidis. There had been a slight increase in salmonellas in cattle and chickens (although not in Scotland) due to serotypes other than S. typhimurium and S. enteritidis;
  2. human data: these showed a continuing fall in salmonellas (mainly reflecting the fall in S. enteritidis PT4). There had been a slight fall in Campylobacter in England and Wales, but not in Scotland. VTEC seemed to be stable at around 900-1,100 p.a, depending on outbreaks. PT21/28 was now the most common phage type. It was planned to look at the epidemiology of phage types. There had been two large S. typhimurium outbreaks - one DT104 (over 300 cases) centred on the West Midlands; the other DT204B, international - both lettuce-associated epidemiologically. There had been S. enteritidis PT5A and 6c outbreaks in Scotland. Otherwise, there had been a general decrease in outbreaks - particularly of PT4 - across the UK. There had been a number of small VTEC outbreaks reported;
  3. surveillance study results: these were as reported to the ACMSF in December 2000. They highlighted S. typhimurium in pigs and Campylobacter in all animals (particularly C. jejuni in cattle and sheep; pigs had the highest levels, but mostly of C. coli). There had been a significant incidence of Yersinia isolations in animals but this was not reflected in humans where there was very little yersiniosis.
  4. Campylobacter sentinel surveillance: about 12 million of the population were covered by participating laboratories. Surveillance included detailed microbiology and a questionnaire. The purpose was to generate hypotheses for further testing. About 20 per cent of infections had been acquired abroad; about 10 per cent had been hospitalised. Species differences in risk factors had been suggested.
  5. poultry-associated outbreaks : data had been considered for the period 1992-99. The ratio of chicken to turkey outbreaks was more or less in accordance with consumption ratios (74 per cent chicken: 25 per cent turkey). Sixty per cent of outbreaks were of Salmonella, 34 per cent of Clostridium perfringens, 6 per cent of Campylobacter. There had been a large fall over time, with the exception of Cl. perfringens.

8. Government's interim response to the Phillips Report of the BSE Inquiry

8.1 In view of the shortage of time available to consider this document (ACM/513), it was agreed that Members should be consulted in correspondence, with a view to a coordinated ACMSF view being assembled for transmission to the BSE Inquiry Liaison Unit. Members were asked to submit their comments to the Secretariat as soon as possible. One Member stressed the great importance of local field investigation in identifying risk factors. This had not happened in relation to vCJD. Unless proper field investigations were carried out, relevant data would not be discovered. Despite constant reminders of this fact, there had been no improvement in the situation over time.

9. Review of lessons from first ACMSF open meeting

9.1 Professor Georgala introduced ACM/514 which consisted of an aide-memoire on the main features of the Committee's first open meeting on 5 December 2000. He hoped that it would help inform consideration of the lessons to be learned from this first meeting which could be applied to future open meetings. The next was scheduled for 5 December 2001 and was likely to be held in the FSA's new headquarters building, Aviation House in Holborn.

9.2 The general view amongst Members was that the first meeting had gone very well. The presence of the public had not served to inhibit Members in the conduct of Committee business. Some of the topics had been potentially headline-grabbing but discussion of these during the course of the meeting had helped clarify the various issues for members of the public present and had served to avoid creating scare stories. It was felt that, as with the first meeting, the next open meeting should be advertised as widely as possible. There was general satisfaction with the way arrangements had been made to ensure that the public access to the work of the Committee was not disrupted by the requirements of the media. Members were content that the media had been asked to conduct any interviews during the break for lunch or at the end of the meeting. There had been a certain amount of feedback indicating satisfaction with the time allocated for public discussion and with the quality of the minutes.

9.3 A number of suggestions were offered for further consideration. One Member felt that the meeting would have benefited from having members of the public closer to the Committee. And another Member thought that there would be advantages in holding the second open meeting at a 'neutral' venue (like the Insurance Hall, where the first had been held) rather than at the FSA's headquarters, to help emphasise the essentially independent character of the ACMSF. It was noted that the agenda for the first meeting had been very full and that there had consequently been significant time pressures in dealing with all of the day's business. It was suggested that this should be borne in mind in planning the second open meeting. Finally, Members expressed their appreciation for the efforts of the Secretariat in planning and arranging the first open meeting.

10. Food Standards Agency's foodborne disease and poultry strategies

10.1 In May 2001, the FSA Board will be considering strategies to achieve the Agency's 2 foodborne disease targets. Dr Hilton presented latest drafts of the proposed foodborne disease strategy (ACM/519 and ACM/519/SUPP) and the poultry target strategy (ACM/520). The foodborne disease strategy would run from April 2001, the date on which the FSA would begin to receive the funding allocated in the Comprehensive Spending Review.

Foodborne disease strategy

10.2 Dealing first with the strategy for reducing the incidence of foodborne disease by 20 per cent by April 2006, Dr Hilton explained that ACM/519 contained an analysis of the main organisms causing foodborne disease, those causing significant morbidity and mortality, the main food vehicles and the organisms involved in outbreaks. There was then a sector-by-sector action plan identifying measures to control pathogens in food and to improve food handling and preparation. The paper went on to consider a strategy for reducing Campylobacter infection, and priorities for action. Amongst the priorities to emerge from the Foodborne Disease Workshop held in November 2000 were the wider implementation of HACCP strategies and enhanced training, education and user-friendly guidance. Following on from the Workshop, a series of measures had been identified in each sector to address foodborne disease and these were incorporated into a plan of action contained in ACM/519. Finally, the paper covered budgetary issues, measuring success and the next steps.

10.3 The foodborne disease strategy paper was supplemented by a further paper (ACM/519/SUPP) which discussed options for establishing the baseline for the foodborne disease target and for enabling progress towards its achievement to be monitored. In introducing this, Dr Hilton stressed that the baseline paper had been provided as background to the strategy paper. It had also been revised in the period since it had first been considered by members of the Surveillance Working Group (the earlier version appearing as Annex D to ACM/511), to reflect comments from Working Group members and from external expert epidemiologists. The revised baseline paper focused on 2 particular options, namely,

  1. a system based on laboratory reporting of all gastrointestinal pathogens; and
  2. a system based on laboratory reporting of selected pathogens.

10.4 The paper recommended the latter option. Under this system, the target would be expressed as a reduction in reports of those pathogens which were most often foodborne and which caused severe morbidity and mortality. Views were invited on whether this approach would provide a reasonable basis for establishing a baseline and providing a robust assessment of foodborne illness. There were also a number of other detailed questions to be addressed. Which pathogens should be included? There was a clear case for including Salmonella, Campylobacter and VTEC O157, but it was for consideration whether SRSVs, Cl. perfringens, Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus should also be included. There was also the question of whether the target should be based on all reports of the individual target pathogens or whether there should be some adjustment to reflect the proportion of foodborne cases (the former approach would avoid the risk of accusations of manipulating the data). Members views were also invited on whether cases acquired abroad should be excluded from the target; whether the target should include an independent measure of the trend in IID; and whether statutory notifications should be explicitly excluded.

10.5 By way of introduction, Professor Georgala recalled that the Committee had, over time, offered wide-ranging advice on tackling foodborne illness. The strategy reflected much of that advice, including that on the greater use of HACCP, improving the microbiological status of poultry meat, helping consumers protect themselves from the risk of food poisoning, addressing the question of foodborne viral infections, etc. The object of the current exercise was not to repeat that process but instead to address the technical issues raised in the papers. It was important for Members to bear in mind the specific purpose of the strategy. It was not designed as a total strategy for ensuring the safety of food and thus did not reflect what, for example, the food industry needed to be doing, day-by-day, in relation to food safety. Nor did it cover such areas as the ACMSF's published advice on vacuum packaging and associated processes and the associated industry code of practice. Rather, it was a targeted strategy for reducing the incidence of foodborne disease by 20 per cent by April 2006. Professor Georgala thought that perhaps these were points worth mentioning in ACM/519.

10.6 In discussion of ACM/519, the following points were made:

  1. whilst the necessities underlying the development of the foodborne disease target were appreciated, the ACMSF saw its role as providing an objective, scientific view on the strategy proposed. Members generally felt that the Committee might have been in a position to provide more helpful advice on developing the strategy had they been consulted earlier;
  2. there were huge variations in current estimates of the level of food poisoning in the UK. These uncertainties would make it extremely difficult to establish a meaningful baseline for foodborne disease and to measure a 20 per cent reduction;
  3. a more guarded assessment of the contribution made by particular industry schemes in reducing levels of Salmonella in poultry and eggs than that given in the paper might be justified (as signalled, for example, in the ACMSF's forthcoming Second Report on Salmonella in Eggs);
  4. the paper contained a number of references linking Cl. perfringens with meat-associated foodborne disease. In fact, the primary causes of such incidents were incorrect cooking, incorrect cooling or incorrect re-heating;
  5. the difficulty with the suggestion that caterers should be encouraged to source their supplies from reputable suppliers was the means by which a caterer would identify a reputable supplier;
  6. the current difficulties in developing a coherent strategy for tackling the problem of Campylobacter represented a significant impediment to the target of reducing foodborne disease by 20 per cent by 2006. It was necessary to avoid the suggestion that further research was the only current available option. Greater focus was needed on practical options;
  7. thermal decontamination should be mentioned in relation to the red meat sector. Also in relation to red meat, there were likely to be limited gains from measures to improve ante-mortem inspection, in the absence of microbiological examination;
  8. a major target in the milk sector should be the improvement of on-farm pasteurisation;
  9. the global approach to reducing foodborne disease implied that there was a single problem, amenable to a single solution. What were needed were tailored measures linked to particular pathogens. Intervention also needed to be targeted according to available evidence about the causes of disease. A broad-brush approach was unlikely to be fully effective. The approach needed to tackle Cl. perfringens, for example, would be completely different to the strategy needed to address SRSV-associated illness;
  10. whilst there was support for the central role of HACCP in any strategy for reducing foodborne disease, legislation, licensing and enhanced enforcement were all likely to be required to ensure satisfactory application of HACCP across the board. New approaches were likely to be required in order to promote a better understanding of hazard control among, eg. small and medium size enterprises, including those catering from home for large functions;
  11. in selecting targets for intervention, it would be preferable to focus on action to improve the microbiological status of particular pathogens in particular areas (eg. Salmonella in eggs or Campylobacter in poultry meat) rather than to take action on particular pathogens on a broad front (eg. reducing foodborne Salmonella generally). It would also be essential to be able to measures progress consistently in the period up to April 2006;
  12. it would be important to establish confidence intervals when measuring reductions in the level of foodborne disease;
  13. with the probable decline in Salmonella in eggs, it was likely to be extremely difficult to measure any future prevalence in absolute terms (eg 1 in 600). Rather, it was likely to be necessary to measure prevalence in 'less than' terms (eg
  14. in terms of establishing baseline data, advantage was seen in using sentinel laboratories linked to GP sentinel practices. Standards protocols for laboratories were regarded as essential. Safeguards were also needed to cover, eg, reporting trends. Salmonellosis mortality statistics were an option that could be considered. A panel approach would be likely to provide better data on population trends for, eg, infections acquired as a result of foreign travel;
  15. the advisability of including in the strategy paper the report of the foodborne disease workshop was questioned, given the mix of participants who had attended the workshop and their varied expertise;
  16. the importance of viruses should not be overlooked.

Poultry target strategy

10.7 Dr Hilton introduced the draft poultry target strategy (ACM/520). The Agency's target was to reduce levels of Salmonella in UK-produced retail chicken by 50 per cent by April 2005. She said that the draft strategy had been based on the outputs from the multidisciplinary stakeholder workshop which the FSA held in October 2000 as well as reflecting existing legislation, codes of practice, etc. It was proposed that, in the first instance at least, the main area of focus for the strategy should be the broiler growing farm (through testing of flocks and scheduling of slaughter so that positive flocks were processed at the end of the day; improved cleansing of poultry crates, and enhanced biosecurity).

10.8 In response, the Chairman welcomed the approach of involving key stakeholders and then synthesising the output into a strategy. The identification of specific targets, as in ACM/520, was a useful starting point. In wider discussion of the paper:

  1. there was agreement on the need to address the problem of effective crate washing;
  2. the operation of the spot market was seen as a limiting factor in relation to effective slaughter scheduling;
  3. it was pointed out that the strains of concern in human health terms were often different from the strains found in livestock. This suggested that more precise targeting of specific strains would be required if intervention was to prove fully effective;
  4. the legislative barriers to the use of terminal decontamination were noted, as was the suggestion that there was little or no benefit to be derived from the use of chlorine to decrease carcass contamination.

11. Any other business

Foot and mouth disease (FMD)

11.1 Mr Gayford drew attention to the likely impact of the foot and mouth disease crisis on prospective on-farm surveillance and research programmes. He would endeavour to provide more specific information for the Committee's next meeting.

11.2 Professor Johnston felt that there might well be some indirect FMD-related issues in the aftermath of the current crisis which were of relevance to the ACMSF and agreed to provide some headings as a basis for future consideration by Members.

High pressure processing

11.3 Dr Simmons (who was also a member of the Advisory Committee on Novel Foods and Processes (ACNFP) reported that ACNFP had received approaches from 2 companies interested in manufacturing high pressure treated fruit based products. The companies had sought a scientific opinion indicating that, with the exception of increasing the shelf life, the process had no effect on the nutritional or organoleptic qualities of the products compared to similar, untreated products. The ACNFP had noted that neither application was supported by sufficient information in a number of areas including operating conditions, the effectiveness of bacterial kill, and the acidifier to be used. ACNFP had therefore proposed a joint Working Group with ACMSF to look at generic issues associated with high pressure processing, with a view to producing operating guidelines similar in nature to those previously produced by the ACMSF in respect of vacuum packaging and associated processes. Dr Simmons had encouraged the ACNFP Secretariat to make a formal approach to the ACMSF, and this they intended to do.

11.4 It was agreed that the question should be considered once the ACNFP's formal request had been received. Attention was drawn to the parallel with the request for ACMSF advice on Sainsbury's in-shell eggs pasteurisation process, and on the difficulties which Members had faced in responding to the request for advice on that issue, given that, unlike ACNFP, ACMSF had no role with regard to process or product approval or authorisation.

12. Dates for remaining meetings in 2001

12.1 Members were reminded that meetings for the rest of 2001 were scheduled for 27 June, 19 September and 5 December, the latter being an open meeting.




3.2 Post ACM/MIN/38 (FINAL) on ACMSF website Posted on website in January 2001
4.3 Professor Georgala to report on meeting with Food Standards Agency (FSA) about in-shell pasteurised egg-type questions Chairman discussed the matter with FSA Chief Executive (Geoffrey Podger) and Deputy Chief Executive (Dr Jon Bell) on 12 December 2000. It was agreed that, for the future, Professor Georgala would be consulted informally to assess whether, and in what form, particular cases should be put to the ACMSF. This would help ensure that matters were dealt with in a way that was likely to elicit the most useful advice.
4.4 Finalise Salmonella in Eggs Report Chairman formally submitted final Report to FSA Chairman on 2 January 2001. Sir John Krebs replied on 14 February agreeing to the Report being published and launched with an ACMSF media briefing.
4.5 M. bovis Working Group The Working Group held its first meeting on 28 February 2001 (agenda item 7).
6.1 Finalise ACMSF Annual Report 2000 Secretariat sent a second draft, reflecting the outcome of the 5 December 2000 meeting, to Members on 10 January 2001. Report formally submitted by Professor Georgala to Sir John Krebs on 1 February 2001. Sir John replied, agreeing publication, on 27 February 2001.
9.12 Scottish Joint E. coli O157 task Force See ACM/MIN/40 (agenda item 7).
11 Zoonotic potential of Norwalk-like calicivirues and rotavirus. Dr Simmons obtained comments from Professor Banatvala on ACM/502 and these were circulated by the Secretariat to the Members on 23 February 2001.
12.5 Advise FSA on recommendations made by Ad Hoc Group on Risk Assessment Secretariat sent FSA two letters : the first, on 16 January 2001 drawing attention to a recommendation for generic risk control models for small and medium size enterprises; and the second, on 17 January 2001, on the importance of consumer advice within the FSA's communications strategy.
14 Respond to letters from Sir John Krebs and Chief Medical Office, Professor Liam Donaldson about how the ACMSF can accommodate the recommendations of the Group led by Sir Robert May (the Government's (then) Chief Scientific Adviser) on risk assessment procedures.
Secretariat to prepare regular information papers on work of other scientific advisory committees.
Secretariat wrote to Sir John Krebs and Professor Donaldson on 15 January 2001.
See ACM/515.

I have attended 2 meetings, the first on 12 December 2000 and the second on 23 February.

A draft Interim Progress Report by the Task Force was issued on 26 January 2001. I will comment on each of these items separately.

Meeting on 12 December 2000

At this, the fifth meeting of the Task Force, food issues were considered and presentations were given on surveillance, food safety, end process treatments and current research. A paper giving an update on the Pennington and ACMSF recommendations, controls in the food chain (including meat, vegetables and retailers), and an update on legislation in Scotland was presented. Some of the points that emerged included:

  1. the transmission of E. coli through animal contact might now be more significant than through food;
  2. the routine surveillance of food for O157 is probably a waste of time;
  3. an economic study of the West Lothian outbreak concluded that the cost over the next 30 years, per person affected, would amount to 168,000;
  4. that consideration should be given to extending butchers licensing provisions to all high risk businesses.

The Task Force heard of some novel processing procedures, including pulsed power technology, pulsed electric fields, pulsed UV light, and plasma treated liquids. Papers were presented on T sticks (these change colour when the desired temperature has been reached) and on methods of ensuring the safety of salad vegetables, including sprouted vegetables. Other presentations were given on the following potential sources of E. coli infection - meat, farmers' markets, bottled water, and small scale cheese producers.

Meeting on 23 February 2001

This meeting was concerned principally with risk assessment, and presentations were given on risk assessment in respect of the following potential sources of E. coli infection - drinking water, farms, the recreational use of animal pasture, open farms, occupational risks, waste and food. In respect of the risk assessment in food, areas of action were divided into high, medium and low priority:

High priority

  1. the safety of fruit, salad and vegetables, as there is no further control of fresh produce between harvesting and sale/consumption. Control measures include education at the domestic level of the importance of washing food and hands;
  2. the supply of beef products, as they have the highest association with faecal contamination. Control measures include the enforcement of cattle ante/post mortem and other current controls;

Medium priority

  1. small scale cheese production is included in this category as cheese production has recently been addressed. Control measures could include enforcement of current provisions;
  2. catering establishments, bottled waters, and farmers¿ markets are included, as there are existing controls on catering, markets and bottled waters. Bottled waters should already be undergoing Quality Control. Control measures could include guidelines and training for the specific sectors.

Low priority

  1. extended licensing is included in this category, as this requires long-term solutions;
  2. new technology is included, as the effects/benefits are unquantifiable;
  3. enhanced labelling is included, as this must be a part of a wider food control initiative.


  1. control contamination at source;
  2. education reinforcement at all stages of consumption;
  3. focus on enforcement of existing controls, enhancing where deficient.


  1. irradiation could help to resolve some food safety issues;
  2. any messages given on food safety should be kept simple;
  3. education and training is preferable to legislation;
  4. concern was expressed regarding the lack of understanding of why food safety precautions are taken;
  5. training should cover the risk from all pathogens, not just O157;
  6. ensure there is no contamination of the product at the primary production stage, thus ensuring that O157 does not enter the domestic environment;
  7. education and evaluation of training is required;
  8. it is for the Task Force to identify the messages, and for other professional bodies to convey these messages.

Interim Report and Guidance

This stated interim findings, namely :

'While much of our Report cannot be finalised until the work is further advanced, the following general themes are emerging clearly:

  1. information and education on the risks and responses to the organism need to be developed so that an understanding of this relatively new and dangerous organism is significantly improved in a way that facilitates change across all sectors of the community such as primary healthcare, farming and recreation;
  2. some of the responses required to combat E. coli O157 are simple and readily achievable (eg. washing hands, cooking foods, separating clean and dirty operations), which may lead to these crucial factors being undervalued by those who need to adopt them;
  3. animal sources, especially excretion to farmland, will receive a high priority in the Task Force's further work;
  4. the protection of private water supplies will similarly be a major concern for the Task Force;
  5. there is a need to reconvene the Working Group under Professor Cairns Smith on outbreak investigation and management;
  6. it will be necessary to recognise the changes that can and cannot be made with the current state of understanding.'

The full report of the Task Force is due in May and should be available on the Web. The website will be the Food Standards Agency website

Dr N A Simmons
March 2001

1. The ACMSF's first consideration of sewage sludge was in the preparation of its Report of Foodborne Viral Infections, Annex E of which describes the treatment and disposal of sewage sludge.

2. There are 3 kinds of treatment:

  1. primary, allowing most of the solids to settle out by gravity;
  2. secondary, a biological treatment stage where microorganisms oxidise the settled sewage; and
  3. tertiary, to enhance the effluent quality, and which may include disinfection.

3. Under the current code of practice, sewage sludge may be used on agricultural land, but safeguards are applied. However, the food industry refused to accept the safeguards and agreed on the Safe Sludge Matrix with Water UK, to govern the application of sewage sludge to agricultural land. This Matrix is shortly to be incorporated into regulations.

4. The disposal of raw sewage at sea is now contrary to EU Regulations. In 1998, UK Water Industry Reseach Ltd (UKWIR), the Environment Agency, and the Department of the Environment, Transport and the Regions jointly commissioned research to characterise the risks associated with the beneficial utilisation of sewage sludge in agriculture. Administration of the research work is performed by UKWIR.

5. The objective of the research work is to assure the safety of current recycling of treated sewage sludge and application techniques, specifically:

  1. to develop analytical procedures for determining human and animal pathogens in sewage sludge;
  2. to study the fate of pathogens during the treatment of sewage sludge; and
  3. to establish, by means of a risk assessment methodology, whether current sewage sludge recycling operations have an observable risk with respect to human and animal pathogens.

6. Phase 1 has been completed and the report is in press. Phases 2 and 3 are on-going, the latter being the subject of independent peer review by the ACMSF. The meeting of the Ad Hoc Group on 13 February was to consider Phase 3. It was essentially a mathematical model about which the Group had a number of reservations which are set out in ACM/512. The water industry delegation asked if the ACMSF could continue to give assistance in the future.

Dr N A Simmons
March 2001