ACMSF minutes: 16 September 2004

The 53rd meeting of the Advisory Committee on the Microbiological Safety of Food will be held at 10.30 am on Thursday 16 September 2004 in Aviation House, 125 Kingsway, London WC2B 6NH. This meeting is open to members of the public.

Present

Chairman:
Professor W Reilly

Members:
Mr J Bassett
Dr D Brown
Dr K Hadley
Mr A Kyriakides
Mr P McMullin
Mr P Mepham
Professor S O'Brien
Mr B Peirce
Mr D Piccaver
Professor L Piddock
Professor P Williams

Assessors:
Mr P Gayford (Defra)
Dr J Hilton (FSA)

Secretariat:
Dr L Foster (Administrative Secretary)
Dr P Cook (Scientific Secretary)
Mrs E Stretton

Others :
Dr R Meldrum: agenda item 7
Members of the public - see Annex I

1. Chairman's introduction

1.1 The Chairman welcomed ACMSF Members and members of the public to the 53rd meeting of the Committee.

1.2 The Chairman also welcomed Dr Richard Meldrum (National Public Health Service, Wales) who would be presenting agenda item 7.

1.3 The Chairman asked Members to identify any items for discussion under any other business at the end of the meeting. Mr Piccaver said that he wished to raise an issue relating to information paper ACM/704.

2 Apologies for absence

2.1 Apologies for absence were received from Professor T Humphrey, Professor M Gasson, Professor P Hunter, Ms S Davies and Ms E Lewis. Apologies were also received from Dr L Doherty (NIDHSSPS; Departmental Assessor).

3 Declarations of interests

3.1 The Chairman reminded the Committee of the need to declare any conflicts of interests relating to items on the agenda. Mr Kyriakides reported, in connection with agenda items 7 and 8, that Sainsbury's sold raw poultry and burgers, and that some burgers were cooked in store. Similarly, Mr Bassett reported that Unilever also sold some burger products. David Piccaver added that he was a salad producer (agenda item 8).

4 Minutes of the 52nd meeting (ACM/MIN/52)

4.1 Members approved ACM/MIN/52 as a correct record of the previous meeting. The Secretariat was asked to arrange for these final minutes to be posted on the Committee's website.
Action : Secretariat

5 Matters arising

5.1 The Chairman drew attention to the Secretariat information paper ACM/699 detailing matters arising from previous meetings. Mr Piccaver requested further information on broken packaging (ACM/MIN/52 paragraph 12.5 refers).

5.2 There were no other matters arising identified by members of the Committee.
Action: Secretariat

6 Working Group on Campylobacter

6.1 The Chairman informed Members that the Working Group on Campylobacter met on 13 September to consider comments received in response to the ACMSF's recent consultation on its Second Report on Campylobacter, which ended on 13 August. The Group agreed a number of changes to the text of the Report, including insertion of an Annex reporting progress made by the Food Standards Agency to meet the ACMSF's recommendations. The Group also agreed to provide comments on a summary of the consultation responses that had been prepared by the Secretariat. A revised draft of the Report, and the ACMSF response to the consultation would be presented to the Committee for final ratification at the December meeting.

7 Survey of Salmonella and Campylobacter contamination of whole, raw poultry on retail sale in Wales in 2003 (ACM/700)

7.1 At the Chairman's invitation, Dr Meldrum (National Public Health Service, Wales) gave a presentation on a 2003 survey of Salmonella and Campylobacter contamination of whole, raw poultry on retail sale in Wales (paper reference ACM/700). Dr Meldrum outlined the sampling methodology used in the survey, including the numbers of samples taken and the breakdown of sampling between different categories of retailer and the proportion of fresh and frozen samples. He provided an overview of the findings, including a comparative assessment with results obtained for a similar survey carried out in 2001/2. Comparative results obtained from retailers and butchers, and fresh and frozen samples were also summarised. Dr Meldrum also outlined findings relating to seasonality of Campylobacter rates, and summarised results comparing the Campylobacter isolation rate from fresh chickens and the human infection rate in Wales in 2003. Summing up, he reported that the results of the work had shown some consistency between both the 2002 and 2003 surveys. There was a similarity in the timing of the early summer Campylobacter peak in the 2002 and 2003 surveys. There was also a similarity in the timing of the early summer peak between human Campylobacter infections and chicken isolation rates. However the prevalence of Campylobacter contamination of chicken remained high in the second half of 2003 which contrasted with the trend seen in 2002.

7.2 At the Chairman's invitation, (in the absence of Professor Humphrey) Mr Kyriakides presented the views of the Working Group on Surveillance. Mr Kyriakides explained that, having reviewed the full report of the survey, the Group had the following comments:

  • The study used a randomised premises selection process to collect samples. This may have resulted in under sampling of products with larger sales volumes. Therefore it would not give a truly representative prevalence. In the context of rolling surveys, to assess the risk of exposure to the pathogen, the sampling process would benefit from being refined, for example, by considering sales volumes per retailer.
  • An indication of confidence intervals for the overall positive rate for Salmonella and Campylobacter was required to assess reductions in the prevalence.
  • For rolling surveys, strict control over cross-contamination was essential. Tight procedures for sampling at premises would need to be in place. In addition, a typing approach was required to assess the association between human cases and poultry isolates.
  • Percentage positive data should be replaced with a calculated rate figure of the number of positive chickens to account for the number of chickens sold at a particular time. This approach would also require a sales-based sampling plan and consideration of seasonal volumes of poultry.
  • Differentiation between intensively reared and extensively reared poultry was missing.
  • Methodology for rolling surveys required standardisation.

    7.3 Dr Cook outlined the Food Standards Agency's proposed strategy for ongoing rolling surveillance. He explained that the Welsh survey formed the basis for a model for future rolling surveillance. The Agency was currently exploring the use of a more extensive sentinel approach for national monitoring of Campylobacter contamination of chicken on an ongoing basis. He added that unlike snap shot-type surveys, a rolling approach would allow representative data to be gathered over time. Inclusion of typing data on Campylobacter and Salmonella isolates would provide information on trends.

    7.4 Members discussed the typing of Campylobacter isolates used in the survey, noting it was not feasible to type all the samples. The proportion of fresh and frozen products sampled in the survey was discussed. Mr McMullin suggested inclusion of a 2x2 matrix table indicating the proportion of fresh and frozen samples in the report. Members discussed traceability of samples taken from independent butchers, and agreed that where possible, sampling officers should obtain information on the provenance of samples. Dr Cook informed members that there were no plans to include Campylobacter enumeration as part of the current rolling survey programme, due to methodological problems highlighted in an earlier survey carried out in 2001.

    7.5 The Chairman thanked Dr Meldrum for his presentation. He requested that the Committee have sight of the final report of the survey.
    Action : Secretariat

    8 Safe Cooking of burgers (ACM/701)

    8.1 At the Chairman's invitation, Dr Cook (FSA) introduced paper ACM/701 on the safe cooking of burgers.

    8.2 Dr Cook explained that in 1997, the Committee considered a range of advice for industry and consumers on the safe cooking of burgers. The Committee's advice formed the basis of the Chief Medical Officer's (CMO) revised guidance issued in 1998. He informed the Committee that, in light of less stringent time/temperature requirements in the USA, the Food Standards Agency had recently been approached by industry with a suggestion that the recommended time/temperature conditions for the cooking of burgers were more stringent than was necessary, and resulted in overcooking. Therefore the Committee's views were being sought on whether the current advice issued by the CMO in 1998 was still appropriate.

    8.3 Among the points made in the discussion of the paper were that:

  • Published E. coli O157 thermal inactivation studies in meat homogenates had demonstrated that application of less stringent USA conditions (70 C for Unlike the USA guidance, the current ACMSF recommendations possessed a margin of safety. This safety margin was recognised as important in view of the low infectious dose of E.coli O157.
  • The ACMSF advice may be too conservative (producing an overcooked product), due to destruction of E.coli O157 occurring during the heating time taken to reach 70 C. Published research carried out by academia had demonstrated that it was possible to lower the temperature/time conditions, whilst still retaining a margin of safety. However strong evidence would be needed to support any reduction in safety margin.
  • Members recognised the difficulties associated with measuring the temperature of burgers, and the high turnover of untrained catering staff particularly amongst smaller businesses. Therefore a safety margin needed to be built into any advice given. Members acknowledged that those working in the catering industry were familiar with the current ACMSF guidance.
  • Since the ACMSF advice had been issued, Members were not aware of any epidemiological data relating to outbreaks of E.coli O157 associated with burgers in the UK.

    8.4 The Chairman thanked Dr Cook for his presentation. He commented that the Committee had expressed a range of views, although the weight of opinion highlighted caution in moving away from established guidelines. He proposed that a short-life ad hoc group should be set up to review the current advice, in the light of the availability of new published evidence. Members agreed with this proposal. He requested that the Group update the Committee on its progress at the March meeting.
    Action: Chairman/Secretariat

    9 Microbial control of doner kebabs (ACM/702)

    9.3 At the Chairman's invitation, Dr Cook (FSA) introduced paper ACM/702 on the microbial control of doner kebabs.

    9.4 Dr Cook explained that the paper outlined the processes involved in the production of doner kebabs. It provided information from microbiological surveys, evidence of outbreaks linked to kebabs and kebab establishments, and details of Local Authority advice on the production, use and storage of doner kebabs. Sales of doner kebabs, and other types of kebabs, appeared to be a growth area in the fast food sector. The findings from microbiological surveys over the last ten years did not suggest a major problem with this type of food. HPA outbreak data suggested that contamination of foods other than or in addition to the kebab meat could also be important, for example salads. Potential hazards associated with the production, storage and use of doner kebabs and kebab meat appeared to be well recognised, with many local authorities providing guidance to shops and caterers via web site related material.

    9.5 In the ensuing discussion, Members agreed that operator competence and handling of the product was key to controlling the microbiological safety of kebab meat. Advice provided by Local Authorities on handling practices and storage of large pieces of meat was conflicting. Therefore, there was a need for co-ordinated national guidance on handling of these meat products. Evidence from New Zealand mirrored that presented in the paper. Members noted that automatic turners were more effective in terms of cooking the meat uniformly and thoroughly.

    9.6 The Chairman thanked Dr Cook for his presentation. He proposed that the Food Standards Agency consider current doner kebab handling practices with a view to standardising Local Authority guidance. In addition he requested that the Committee should be updated on evidence relating to outbreaks arising from the contamination of salads.
    Action: Secretariat

    10. Committee sub-groups

    Ad Hoc Group on Infant Botulism

    10.1 At the Chairman's invitation, Professor O'Brien updated members on the outcome of the fourth meeting of this Group, which took place on 8 September. At this meeting, the Group received presentations from several Local Authorities giving guidance to companies producing minimally processed infant weaning foods. From these presentations it was apparent that Environmental Health Officers taking account of the same spectrum of evidence, had reached opposing views in relation to the risks associated with the production of this type of product. The Health Protection Agency also provided information on estimates of the likelihood of an infectious dose of C.botulinum being present in cans of formula associated with a case of botulism. The Group concluded that a semi-quantitative risk profile was required in order to provide a scientific basis for any recommendations. Professor O'Brien therefore sought the Committee's views on the mechanism by which such a risk profile should be carried out by the Group.

    10.2 Members agreed that a small sub-Group of experts should be set up to carry out a risk profile. In addition, Mr Bassett (Member with expertise in risk assessment) should be co-opted onto the ad hoc Group. The Food Standards Agency agreed to identify resources to fund mathematical modelling work that might be needed to support the risk assessment. The Chairman requested that Professor O'Brien provide an interim report to the Committee at its December meeting.
    Action: Professor O'Brien/Secretariat

    Imported Foods

    10.3 At the Chairman's invitation, Mr Mepham informed Members that a meeting of this ad hoc Group would take place that afternoon, in order to take forward the work areas highlighted for investigation at the December 2003 ACMSF meeting.

    Newly-emerging pathogens

    10.4 At the Chairman's invitation, in the absence of Professor Hunter, Dr Foster informed the Committee that final testing of the message board was complete. The accompanying guidance notes had also been tested and Members had now fully signed up to the board rules. She added that Members would receive usernames, passwords and guidance notes shortly.

    Botulism in cattle

    10.5 The Chairman informed Members that the ad hoc Botulism in cattle Group was due to meet on 23 September. Draft Terms of Reference for this Group had been circulated for consideration by Group Members.

    Risk assessment

    10.6 The Chairman informed the Committee that the ad hoc Group on risk assessment was due to hold its first meeting on 28 October. The terms of reference of this Group were to consider whether the ACMSF would be helped by following a formal structure for the process of risk assessment; and if so, to recommend an appropriate structure which might be adopted.

    10.7 The Chairman thanked all the Chairs for their contributions.

    10 Dates of future meetings

    10.3 The Chairman brought to Members' attention paper ACM/703 which listed the dates for further ACMSF meetings in 2004 and the dates for the meetings in 2005. Members were asked to note that for meetings in 2005, the autumn meeting had been rescheduled to take place on 22 September.

    11 Any other business

    11.3 Mr Piccaver made an observation that the information paper on the implementation of the Food Standards Agency's Foodborne Disease Strategy (ACM/704) failed to refer to the Meat and Livestock Commission (MLC) in its Annex on page 15. Dr Hilton confirmed that the Food Standards Agency was jointly funding a project with the MLC to implement a ZAP (Zoonoses Action Plan) Salmonella monitoring scheme in pigs. Mr Piccaver also queried when the manure guidelines for growers would be available. Dr Hilton confirmed that following a meeting of stakeholders over the summer period, a public consultation on the revised draft would take place late in 2004.

    11.2 Professor Piddock requested that information relating to the breakdown of the pathogens represented in the figure in paper ACM/704 should be made available. Dr Hilton explained that the data formed part of a paper, which was presented to the FSA Board that month, which focussed on monitoring of the Agency's foodborne disease target. She added that within this overall figure, the levels of Campylobacter had decreased since the start of the strategy, although levels of Salmonella had remained more or less unchanged. The Chairman requested that a background paper providing a breakdown of trends in levels of the key pathogens comprising the foodborne disease target should be provided to the Committee.
    Action: Secretariat

    12 Public questions and answers

    12.3 The Chairman invited the members of the public present to ask any questions they might have on the work of the Committee, or to make any statements.

    12.2 There were no items raised.

    13. There being no further business, the Chairman thanked Members and members of the public for attending and closed the meeting.

    ANNEX I

    LIST OF MEMBERS OF THE PUBLIC AND OTHERS ATTENDING THE ACMSF'S 53RD MEETING

    Mr M Attenborough MLC
    Mr J Gazzard ADAS
    Mr A Long VEGA
    Dr B Mitchell HPA
    Ms G Mulholland Defra
    Dr T Quigley Food Safety Promotion Board of Ireland
    Mr A Watt