ACMSF minutes: 18 September 2003

Minutes of the 49th meeting of the Advisory Committee on the Microbiological Safety Of Food held on 18 September 2003 at Aviation House, 125 Kingsway, London at 10.30am.


Professor D L Georgala

Dr G R Andrews
Ms S Davies
Dr K M Hadley
Professor T J Humphrey
Professor A M Johnston
Mr A Kyriakides
Ms E Lewis
Mr P Mepham
Dr S J O'Brien
Mr B J Peirce
Mr D J T Piccaver
Dr T D Wyatt

Mr H Bailie (DEFRA)
Dr J Hilton (FSA)
Dr M Patterson (NIDARD)

Mr C R Mylchreest (Administrative Secretary)
Mrs E A Stretton
Miss C L Wilkes
Mr S Rahman

Ms G V Hoad (FSA): for agenda item 8

1. Chairman's introduction

1.1 The Chairman welcomed ACMSF Members to the Committee's 49th meeting. He also welcomed members of the public and others present (details at Annexe I). He extended a particularly warm welcome to Ms Lewis and Dr Wyatt who were returning to the Committee after periods of ill health. Ms Lewis explained the reasons for her long absence.

1.2 The Chairman briefly outlined the format of the day's proceedings and dealt with a number of housekeeping matters.

2. Apologies for absence

2.1 Apologies for absence were received from the following Members: Dr Brown, Professor Gasson, Professor Hunter and Dr Sandifer.

2.2 Apologies were also received from the following Assessors: Mr Gayford (DEFRA), Mr Bailie deputising; Dr McIlroy (NIDARD), Dr Patterson deputising; and Mr Wearne (FSA/Wales). There were also apologies from the Scientific Secretary, Dr Cook.

3. Declarations of interest

3.1 The Chairman reminded Members of the need to declare interests in any of the agenda items. He drew attention to the fact that more general interests were recorded in the ACMSF's Annual Reports. He explained that the Secretariat would shortly be approaching Members for details of their current interests, which would be recorded in the Committee's Annual Report for the 2003 calendar year.

3.2 Dr Andrews declared interests in connection with agenda items 8 and 9. Northern Foods plc were manufacturers of baby foods and vacuum packaged convenience foods.

3.3 Mr Kyriakides declared an interest in relation to agenda items 8, 9 and 11. Sainsbury's were retailers of baby foods, vacuum packed foods, and raw mushrooms.

3.4 Mr Piccaver declared an interest in relation to agenda item 9. His companies produced vacuum packaged salads.

4. Minutes of the 48th meeting (ACM/MIN/48 (REV.1))

4.1 Members approved draft minutes ACM/MIN/48 (REV.1) as a correct record of the previous meeting. The Secretariat would now have these posted on the Committee's website. Action: Secretariat

5. Matters arising (ACM/650)

5.1 Members noted ACM/650, prepared by the Secretariat, charting progress in dealing with the various matters arising from the minutes of the previous meeting.

6. ACMSF Second Report on Campylobacter (ACM/651)

6.1 The Chairman introduced ACM/651, a nearly complete first draft of the Campylobacter Working Group's Report, and invited Members' comments. The aim would be to submit the draft to the Food Standards Agency (FSA) once the ACMSF was content with it. He explained that work was still needed in a number of areas, eg. in relation to the efficacy of freezing and heat treatment; the planned Chapter on poultry meat other than chicken meat; and the proposed changes in European Union meat hygiene inspection procedures. There was also a certain amount of editorial work required, particularly in relation to the references.

6.2 The Chairman explained that the Campylobacter Working Group would meet again on 8 October to finalise the draft, including reflecting any comments emanating from the current meeting. Because the draft Report was not yet complete and had not been submitted to the FSA, it was not currently being posted on the ACMSF's website. It was hoped that any additional or revised material generated by the Working Group could be cleared with Members of the full Committee in correspondence during October/November.

6.3 The Chairman anticipated that a complete draft of the Report would be publicly available towards the end of the year, and that the final Report would be published around the middle of 2004, following a period of public consultation. He said that getting the Report to the FSA as early as possible, thus maximising its value to the Agency in developing its campylobacter strategy, had been a constant feature of the Campylobacter Working Group's deliberations. For that reason, the Group had not addressed the medium and longer-term research opportunities and needs where there were significant knowledge gaps. The Working Group would consider meeting again at a later date to review possible research requirements and the need to prepare a research supplement to the Report.

6.4 In the ensuing discussion, Members made a number of detailed comments on the draft report. The Secretariat was asked to summarise these for consideration by the Campylobacter Working Group on 8 October 2003. Action: Secretariat

7. Mycobacterium bovis in meat (ACM/652)

7.1 The Secretary introduced ACM/652 which discussed preliminary results from FSA-funded research to investigate whether M. bovis was present in the edible tissue of salvaged carcasses of cattle that had reacted positively to the tuberculin test. These results showed that viable M. bovis was present in about 21% of 135 cattle with no visible lesions or with a single lesion, and in just under 5% of edible tissues from such cattle. At the FSA's request, Members were being asked to assess the impact of the results on the ACMSF's risk assessment, published in January 2002.

7.2 The Secretary said that ACM/652 concluded that, because the Committee's risk assessment was based on human M. bovis TB data, not meat inspection data, the FSA research results should not affect the outcome of the assessment. The paper drew attention, however, to a number of pertinent developments – the proposal to discontinue the arrangement under which cattle over thirty months of age were kept out of the food chain; the increasing incidence of M. bovis in cattle; and the increase in numbers of reactor cattle. These factors could lead to an increase in M. bovis-contaminated meat and the level of human exposure. The paper therefore recommended drawing fresh attention to ACMSF recommendations on enhanced surveillance of human M. bovis TB cases, and certain risk management options.

7.3 In the ensuing discussion, the following points were made:

  • in relation to paragraph 15 of the paper, not all meat from cattle was thoroughly cooked;
  • it was not clear from the preliminary results of the FSA-funded research whether viable M. bovis had been found in muscle meat and it would have been helpful to have had this information;
  • in response to a question about possible risk from M. bovis in milk and dairy products, it was stressed that ACMSF's estimate of a maximum of 24 new M. bovis TB cases a year would cover all food exposure pathways (not just meat);
  • it was noted that the European Food Safety Authority (EFSA) was currently considering the heat treatment option (one of the risk management options suggested in the ACMSF's M. bovis Report). Since 20 months had now elapsed since that report had been published, Members hoped that EFSA would make its recommendations to the European Commission quickly.

7.4 In conclusion, the Committee agreed that the preliminary results from the FSA-funded research did not alter the outcome of the ACMSF's risk assessment. However, Members agreed that fresh attention should be drawn to the Report's recommendations about maintaining enhanced surveillance of human M. bovis TB and alerting the FSA to any significant indications that eating meat from M. bovis-infected cattle constituted a health risk. Members also agreed that the ACMSF should recommend to the FSA that it review its decisions on the heat treatment option and the proportionality of the cold storage option.

8. Infant botulism: precautions for the processing of baby foods (ACM/653)

8.1 Ms Hoad introduced ACM/653. She said that it had come to the FSA's attention that new types of food product, for babies from 4 to 12 months old, were being manufactured and sold in the UK. There was concern that these new products, which were chilled or frozen pureés, had not been heat processed sufficiently to destroy Clostridium botulinum spores. There was thus a potential risk of infant botulism, a very rare disease in the UK. Ms Hoad summarised the information contained in ACM/653 and invited the ACMSF's view on the risk associated with these types of product, specifically in relation to Cl. botulinum and infant botulism. She explained that the FSA had received requests from local authorities and food manufacturers on the safety of these new baby foods and the ACMSF's views would help inform the Agency's response.

8.2 In discussion of the issues raised in ACM/653, it was agreed that infant botulism was rare in the UK but that there was a potential risk if the products concerned were not being heat processed sufficiently to destroy Cl. botulinum spores which babies could then ingest. It was noted that encouraging product diversification could mean that smaller sized enterprises which did not have the scientific or technical expertise available to the major food manufacturers might now be producing these types of product. Even product made by the major manufacturers would constitute a potential risk if it were not subject to appropriate heat processing. On the other hand, it was also noted that many foods, both commercially and home-produced, given to babies are not, nor have ever been, sterilised to destroy the spores of Cl. botulinum.

8.3 Members agreed that an Ad Hoc Group should be set up to assemble further information about the products and processes concerned, and to formulate advice which could be considered by the full Committee for submission to the FSA. Action: Chairman/Secretariat The Chairman thanked Ms Hoad for her presentation.

9. Clostridium botulinum: precautions for vacuum packaged/modified atmosphere packaged products (ACM/654)

9.1 Dr Hilton introduced ACM/654: FSA guidance on the safety and shelf-life of VP/MAP chilled foods with respect to psychrotrophic Cl. botulinum. She recalled that the need had been seen for a simplified version of the advice contained in the ACMSF's Report on Vacuum Packaging and Associated Processes, as amplified, and the industry's Code of Practice. The ACMSF had already commented on an earlier draft of the advice. The current draft reflected those comments, as well as setting the context for the guidance, and identifying the target audience. Members were invited to comment on the content of the guidance document in advance of its going to public consultation.

9.2 In discussion of the guidance, the point was made that many exporters to the UK market regarded the ACMSF guidance as disproportionate given the rarity of food-associated botulism in the UK. Expecting UK manufacturers to comply with the guidance could result in increased import penetration. The danger of post-retail temperature abuse was also noted.

9.3 On the other hand, it was pointed out that the ACMSF was bound to frame its advice in the light of the best scientific information available, and against the background of the very high mortality rates associated with botulism. The Chairman also reminded Members that they were being asked to consider whether the FSA guidance faithfully reflected the ACMSF's advice, not to review the Committee's Vacuum Packaging Report.

9.4 Members agreed that the guidance did indeed reflect the ACMSF's advice and that it was suitable for public consultation. The Chairman said that manufacturers would have an opportunity during the consultation process to comment on proportionality and this question could then be addressed by the FSA.

10. Avian Influenza risk assessment: progress report

10.1 The Secretary reported that it had been intended that Dr Brown should provide an oral progress report on his work to assess the risk to humans of Avian Influenza through food chain exposure pathways. Unfortunately, he had been delayed abroad and had thus been unable to attend the meeting. However, since the Committee's 26 June 2003 meeting, Dr Brown had had an opportunity to consult external experts and he now hoped to be in a position to present a formal risk assessment to the ACMSF on 4 December 2003. Action: Dr Brown

11. Raw mushrooms: consumer advice (ACM/655)

11.1 Dr Hilton introduced ACM/65. She explained that, as a result of testing of catering and wholesale mushrooms sampled by environmental health officers in Lancashire in spring 2001, Salmonella kedougou had been found in raw mushrooms from Northern Ireland. The FSA had therefore issued advice to consumers to wash, peel and cook mushrooms prior to use. The source of the contamination had been identified as sugar beet lime from the casing material. The mushroom industry had agreed to cease using sugar beet lime in casing manufacture until such time as they could provide evidence that it was pathogen-free. A code of practice for mushroom casing in Northern Ireland and the Republic of Ireland had been produced (Annexe C of ACM/655). Salmonella testing of casing and mushrooms had also been introduced (Annexe D). Only one sample, of compost (in May 2001), had tested positive (for Salmonella typhimurium).

11.2 Dr Hilton said that, against the background of the work undertaken by the mushroom industry since the incident, the FSA was now seeking an ACMSF view on whether the Agency's advice to consumers 'to peel and cook' mushrooms before use could now be withdrawn (ie. advice to wash them would remain in place).

11.3 A number of points were raised in discussion, including:

  • mushrooms were more likely to be wiped than washed as they tended to absorb water (although it was noted that tests carried out in the aftermath of the S. kedougou episode had tended to suggest that uptake of water was minimal);
  • although the original advice to consumers had been contained in press releases issued by the FSA and the Food Safety Authority of Ireland, there were difficulties inherent in keeping advice before the public. Point of sale material was probably the most effective medium.

11.4 Noting that the advice had been introduced in response to a particular problem which had subsequently been addressed and eliminated, Members indicated that they were content for the 'peel and cook' element of the Agency's advice to be withdrawn. However, Members asked for it to be made clear that they were referring to commercially-cultivated mushrooms only, not to wild mushrooms.

12. Horizon scanning

12.1 The Chairman recalled that, as part of its horizon scanning, the Committee had set up 3 Ad Hoc Groups to look at particular issues. Discussions were still proceeding with the Chairman of the Newly-Emerging Pathogens Group (Professor Hunter) aimed at developing an appropriate approach for taking matters forward. The 2 other Groups, on Imports (Chaired by Ms Davies) and on Changing Social Habits (Chaired by Dr Andrews) had made progress and he invited the Chairs of these Groups to report on progress.

12.2 Ms Davies said that, in accordance with its terms of reference, the Imports Group had been assembling information on the current situation with regard to imports, in order to decide whether there were any potential problems in relation to the microbiological safety of food and so that it could advise the Committee on the need for further action. The Group had agreed to confine its deliberations to legally imported foodstuffs. The Group had met, for the second time, on 12 August when Members had received presentations from the FSA on traceability and (briefly) on the consolidation of EU food hygiene legislation, from DEFRA on veterinary checks at UK point of entry for products of animal origin, and from HM Customs and Excise on that Department's role in relation to food imports. The Group was next due to meet on 8 October when it would give further consideration to the EU consolidation question. It was also hoped that the FSA might provide an overall view of the Agency's policy on horizon scanning, imports and alerting systems.

12.3 The Group's preliminary conclusions were that there appeared to be gaps in the controls on imports of non-animal origin (compared with those in place for products of animal origin); that benefits would accrue from a consistent approach to monitoring foodborne disease in countries exporting food to the UK; and that any human health risk from imported food could be more effectively managed if there was coordination of import controls across the various agencies concerned.

12.4 Dr Andrews said that the Changing Social Habits Group had met for the final time in the previous week. The Group had considered a number of aspects of changing social habits, including:

  • catering – the growth in out-of-home eating and the potential problems associated with an ever changing, culturally, educationally and ethnically diverse workforce;
  • the loss of domestic culinary and hygiene skills;
  • the increase in numbers of elderly persons living in nursing homes, etc;
  • the position of people who were immuno-compromised.

12.5 Ms Davies and Dr Andrews said that they hoped their respective Groups would be in a position to report to the full Committee by December 2003. Action: Ms Davies/Dr Andrews

13. Dates of future meetings (ACM/656)

13.1 The Chairman drew attention to ACM/656 which gave the dates and venues for ACMSF meetings in the remainder of 2003 and 2004.

14. Any other business

14.1 In response to a Member's questions about the recent listeria outbreak implicating butter, and about whether the FSA had any plans for the surveillance of listeria in ready-to-eat foods, Dr Hilton undertook to provide a briefing paper on the outbreak for the December meeting. Action: Dr Hilton She said that there were on-going investigations on practices which might have led to the problem. On the question of surveillance, the Agency was considering moving away from one-off surveys, because of the high set-up costs, and towards a programme of rolling surveys instead. The scope for looking at listeria could be considered in that context.

15. Public questions and answers

15.1 The Chairman invited members of the public and others present to ask any questions or raise any points about the Committee's work.

15.2 Dr Barbara Lund drew attention to the fact that, in the USA, the number of reported cases of infant botulism was 3-times the number of reported cases of foodborne botulism in adults, suggesting that prevention of infant botulism merited serious attention. Whilst it was not certain that all cases of infant botulism were food-related, food was an effective vehicle by which Clostridium botulinum spores could gain access to the infant gut. It had been reported in the USA in 1978 that 4.3% of cases of sudden infant death syndrome (SIDS) were associated with Cl. botulinum spores and/or toxin, and it had been concluded that intestinal production of botulinum toxin was one cause, but not the only cause, of SIDS.

15.3 Dr Lund said that the first reported case of infant botulism in Finland had occurred in 2002. The cause of death had been diagnosed initially as SIDS. In the UK in 2001, there were 372 reported cases of SIDS. Dr Lund wondered how many of those had been investigated for evidence of infant botulism. She asked whether there was a need to investigate more closely the incidence of infant botulism in the UK, in order to assess the risk of infant botulism.

15.4 In response, Dr Hilton said that the question had been considered in great detail following a case of infant botulism in the UK in 2002. A wealth of information was available which had not been included in ACM/653. The available information gave no grounds for concluding that infant botulism was being misdiagnosed as SIDS in the UK.

15.5 Dr Lund also had some detailed comments about the FSA's guidance document for vacuum and modified atmosphere packed chilled foods (ACM/654). The Chairman pointed out that the Agency was shortly proposing to consult on the document. That would provide Dr Lund with an opportunity to comment on the draft.

15.6 Dr Norman Simmons noted that washing meat was a common practice and thought that robust scientific justification would be required if people were to be persuaded to discontinue the practice.

15.7 With regard to M. bovis, he explained that the ACMSF Working Group, of which he had been a member, had taken a worst case approach (ie, meat the sole food exposure pathway; food exposure able to cause respiratory TB in humans). On that basis, the Group had estimated that a maximum of 24 new cases of M. bovis TB each year could be associated with eating meat from infected cattle. It was clear that M. bovis was in meat. What remained to be established was whether it was causing human illness, and currently there was no evidence of disease.

15.8 Dr Bernard Rowe commented on the lack of progress on campylobacter typing and the fact that, because of current practice, the ACMSF had felt obliged to issue a reminder that, where the objective was to make an assessment of campylobacter across the food chain in relation to human infection, veterinary, food and clinical laboratories should use the same methods. He regarded the Committee's support of MLST as brave because he thought that something rather more mundane might be required in practice. He wondered whether the Health Protection Agency's Campylobacter Sentinel Surveillance Scheme would yield useful typing information. Dr O'Brien said that the data set was very large but she hoped that relevant typing information would be available by the time the draft of the ACMSF's Second Campylobacter Report was ready.

15.9 Mr Alan Long stressed the important contribution made by animal welfare to food safety. Attention needed to be paid to the conditions in which animals were housed and the health of the animals. He regarded cheap food as synonymous with disease.

15.10 Mrs Judy Brander made a number of points. She was grateful for the steps the ACMSF had taken on openness. She noted that many consumers had switched from red meat to poultry meat on health grounds and were now confused over whether or not chicken meat was safe to eat. There was concern about TB in cattle. Account needed to be taken of the link with other mammals and the pattern of animal movements. Mrs Brander recalled from her time at University that rice cooked in bulk and left overnight had been identified as a risk in relation to Clostridium botulinum. She would welcome more detailed information in future ACMSF reports on the basis on which risk had been assessed. Mrs Brander said that she would be writing to the Committee on a number of matters including the question of microbial antibiotic resistance.

15.11 On the question of supporting information, the Chairman pointed out that ACMSF's reports were all extensively referenced. He also identified as useful sources of information on pathogens and foodborne disease the FSA's Report of the Study of Infectious Intestinal Disease in England, and the Health Protection Agency's publications and data sets.

Annexe I

Members of the public and others attending the ACMSF's 49th meeting

Dr Roy Betts, Campden and Chorleywood Food Research Association
Mrs J Brander, National Council of Women of Great Britain
Miss Sharmaine Clarke, Food Safety Protection Board
Miss Ouafa Daoudi, Food Standards Agency
Mr Andy Davies, Infant and Dietetic Foods Association
Ms Kaarin Goodburn, Chilled Food Association
Mr B Kainth, FSA
Mr Simon Kane, Kraft Foods UK Ltd
Mr Alan Long, Vega
Dr Barbara Lund, Institute of Food Science and Technology
Ms Helen McDermott, Food and Drink Federation
Dr Bernard Rowe
Ms Satnam Sagoo, Health Protection Agency
Dr Norman Simmons
Dr Roger Skinner
Dr Henry Smith, HPA Laboratory of Enteric Pathogens