ACMSF minutes: 8 June 2006

Meeting held in Aviation House, 125 Kingsway, London WC2B 6NH


Professor S O'Brien

Mr J Bassett
Dr D Brown
Mrs V Buller
Professor M Gasson
Dr R Holliman
Professor T Humphrey
Professor P Hunter
Mr A Kyriakides
Mr P McMullin
Dr S Millership
Mrs J Morris
Professor L Piddock
Professor P Williams

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

Secretariat :
Dr L Foster (Administrative Secretary)
Dr P Cook (Scientific Secretary)
Mrs J Spencer

Members of the public

Chair's introduction, apologies for absence and declarations of interest
1.1 The Chair welcomed ACMSF Members and members of the public to the 59th meeting of the Committee. She also welcomed Dr Kathryn Callaghan (FSA) and Professor Mike Peck (Institute of Food Research) who would be presenting agenda item 6, Dr Richard Meldrum (National Public Health Service, Wales) who would be presenting agenda item 7, and Dr Jim McLaughlin (Health Protection Agency) who would be presenting agenda item 10. In addition she welcomed Ms Tanya Green (FSA) who would be presenting agenda item 11. The Chair welcomed three new ACMSF Members to the Committee – Dr Richard Holliman, Dr Sally Millership and Mrs Jenny Morris, who each provided a brief pen portrait.

1.2 The Chair also formally recorded her thanks on behalf of the Committee to Philip Mepham, Dr Quentin Sandifer and Dr Kay Hadley who retired from the Committee on 31 March. She also thanked Professor Bill Reilly for his considerable work and commitment as Chair of the ACMSF since June 2004 and wished him well in his new post as the FSA Board Member for Scotland. Lastly, she thanked Mrs Liz Stretton for her huge contribution and support over several years through her work as the ACMSF Secretariat.

1.3 The Chair asked Members to identify any items for discussion under any other business at the end of the meeting. Professor Piddock indicated she wished to raise an item relating to paper 788 linked to a review of Microbiological science and research.

1.4 The Chair informed Members of one change to the agenda. Paper ACM/781 (Listeria update) would be replaced by an oral presentation. Slides related to this presentation had been tabled for the meeting.

Apologies for absence

2.1 Apologies for absence were received from Ms Sue Davies, Ms Eva Lewis, and Mr Robert Rees.

Declarations of interests

3.1 The Chair reminded the Committee of the need to declare any conflicts of interests relating to items on the agenda. Mr McMullin reported that, in connection with agenda item 7, his Company provided veterinary services to primary producers and the poultry industry. Mr Kyriakides reported that, in connection with agenda items 6, 7, 8 and 9 Sainsbury's sold vacuum packaged foods affected by shelf life times (agenda item 6), poultry (agenda item 7), burgers (agenda item 8) and infant weaning products (agenda item 9). Mr Bassett reported that, in connection with agenda items 6 and 8 Unilever sold vacuum packaged foods (agenda item 6) and some burger products (agenda item 8). Professor Mike Gasson reported that, in connection with agenda item 6 he was an employee of the Institute of Food Research.

Minutes of the 58th meeting (ACM/MIN/58) and matters arising
4.1 Members approved ACM/MIN/58 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

5.1 The Chair drew attention to the Secretariat information paper ACM/776 detailing matters arising from previous meetings. Mrs Morris queried whether the Food Standards Agency had been in discussion with the Health Protection Agency about its recent review of the provision of laboratory services and Professor Humphrey declared an interest as an ex-employee of the Public Health Laboratory Service. He reiterated concerns previously raised at the Committee relating to the impact of cuts in funding on the timeliness and quality of data from HPA. Dr Hilton replied that, as yet, this issue had not been discussed in detail. She added that comments raised previously by the ACMSF relating to the implication of cuts in HPA funding were being taken forward with the HPA and the Department of Health. There was nothing further to report from the Department of Health as discussions relating to HPA funding were still in progress. The Chair concluded that as this was an ongoing issue it should remain on the agenda until the outcome of discussions relating to funding was known.
Action: Secretariat

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

Vacuum-packaged and modified atmosphere packaged foods
6.1 At the Chair's invitation, Dr Kathryn Callaghan (FSA) introduced paper ACM/777. She explained that in December 2004 the ACMSF requested that the FSA commissioned an independent review of the current scientific evidence concerning vacuum and modified atmosphere packaged foods and the risk of Clostridium botulinum. This followed concerns raised in response to the Agency's consultation on its guidance on the safety and shelf life of vacuum and modified atmosphere packed chilled foods regarding the proposed shelf life limitation of 5 days (based on 1995 ACMSF advice) for chilled products, and products stored above 5°C where failure to support growth of C. botulinum had not been established. This review, which had been carried out by the Institute of Food Research, had now been completed. A summary of the review's findings was annexed to the paper. She added that the full report of the review would be available in due course. Summing up, she explained that the views of the ACMSF were sought on whether to support the 10-day shelf life recommendation.

6.2 At the Chair's invitation, Professor Mike Peck (Institute of Food Research) presented an overview of the work carried out to review the current scientific evidence concerning vacuum and modified atmosphere packaged foods and the risk of Clostridium botulinum. He summarised information on sales of chilled food, current guidance and recommendations for commercial chilled foods, and recent incidence of foodborne botulism in different countries including the UK. He also outlined growth and toxin formation by non-proteolytic C.botulinum at or at less than 10°C. Lastly, he described the effects of other factors including unknown controlling factors, packing in air and re-packing of chilled food.

6.3 The Committee welcomed the review, and in particular, inclusion of epidemiology in the scope of the research. In discussing the proposed recommendation to increase shelf life from 5 to 10 days the Committee noted that:

  • FSA needed to consider risk management issues such as costs/benefits and environmental impact of changes to the guidance;
  • Levels of C. botulinum inoculum used per pack for challenge testing were higher than levels of toxin typically produced by C. botulinum in foods (and referred to previous ACMSF work on infant botulism);
  • Epidemiology of C. botulinum over last 20 years showed that there were no reported cases of botulism linked to chilled foods. However Members noted that botulism was a difficult diagnosis to make and that under recognition of milder cases was possible.
  • The 10-day shelf life recommendation for the UK was already quite restrictive and it was not applied in many other countries.

6.4 Summing up, the Chair confirmed that the Committee endorsed the recommendation to support a 10-day shelf life recommendation with the vacuum packaged Guidance document being revised from less than or equal to 5 days to less than or equal to 10 days at 8 degrees C. The Committee also identified a need for simple, summarised guidance to help enforcers and industry and agreed that a small group should be set up by the Food Standards Agency to deliver this. In addition, this guidance should be brought to the attention of other Member States via the European Commission.
Action: FSA

Update on poultry surveillance (ACM/778)
7.1 At the Chair's invitation Dr Richard Meldrum (National Public Health Service, Wales) presented the findings of the 2005 survey of Salmonella and Campylobacter in raw chicken in Wales and Northern Ireland.

7.2 Dr Meldrum provided an overview of the project including Salmonella and Campylobacter contamination rates, results for samples taken from retailers and butchers, fresh and frozen samples, packaging, producers and a comparison of data from Wales and Northern Ireland. He explained that 2005 was the fourth complete year that raw chickens had been sampled in Wales, and the second complete year of sampling in Northern Ireland. He also explained that unlike previous years the methodology used to measure levels of Salmonella and Campylobacter was now identical to that used for the CLASSP study in England. Results for the 877 samples taken between March-December 2005 indicated that the Campylobacter and Salmonella contamination rates were consistent with those of previous years.

7.3 Members discussed the quality assurance between laboratories noting that 25% of samples were randomly sent to reference laboratories. All the laboratories involved in the survey were UK accredited and followed EQA and IQC schemes. Members highlighted the need to swap samples between laboratories in order to be able to eliminate artefactual results and draw comparisons between samples analysed by laboratories in Wales and Northern Ireland. The Committee queried the omission of data on antimicrobial resistance from this survey, noting that this information had been included in previous years. Members also raised the need to include additional information on salmonella serotyping and campylobacter speciation, for example Salmonella Typhimurium and Salmonella Enteritidis. This information was considered important to poultry producers. Members also recognised that that it would be difficult to increase sample numbers, as Local Authorities were limited in terms of resources. However Members agreed that it would be helpful to calculate the power of the study in retrospect to facilitate comparison with data collected in previous years.

7.4 Summing up, the Chair noted the following points for Dr Meldrum's consideration for future surveys:

  • Inclusion of information on speciation of Salmonella and Campylobacter;
  • Quantification of bacterial load;
  • Determination of antibiotic resistance of isolates;
  • Quality Assurance protocols to ensure comparability of data between laboratories in Wales and Northern Ireland;
  • Carry out retrospective power calculations

Action: Dr Meldrum

Safe cooking of burgers (ACM/779)
8.1 At the Chair's invitation Professor Peter Williams introduced paper ACM/779. He reminded Members that in June 2004 the FSA had sought the Committee's views on whether the current advice on the safe cooking of burgers issued by the Chief Medical Officer was still appropriate. In response to this request the Committee set up an ad hoc Group to review the guidance and formulate recommendations to support development of ACMSF advice to the FSA. The Group met on four occasions over a period of 12 months and considered documentary and verbal evidence relating to the epidemiology of E.coli O157 and other key pathogens, and guidance and cooking conditions for burgers used in the UK, US and other countries. The Group also reviewed published scientific evidence and information submitted by a fast food chain and considered a modelling approach to setting confidence limits.

8.2 Key recommendations arising from the report were that:

  • The advice for safe cooking of burgers should remain at 70°C for 2 minutes or equivalent. Use of lower time/temperature combinations could be considered where producers demonstrate through a risk assessment approach that the final product is safe, and that the process is under effective control.
  • A z-value of 6.0°C should be used for time/temperature equivalents for burgers, particularly below 65°C.
  • A modelling approach to set recommended time/temperatures based on required inactivation levels and required limits of confidence should be considered.
  • Advice to consumers and caterers on cooking of burgers should be reiterated.

8.3 The Committee welcomed the report and registered their agreement with the conclusions proposed by the ad hoc Group. Members reiterated that the current advice should remain at 70°C for 2 minutes or equivalent, noting that the original CMO's advice was produced in response to outbreaks of E.coli O157, which had subsequently diminished. Members added that there might be a tendency for individuals cooking burgers to undercut minimum cooking times. Therefore any reduction in the current time/temperature requirements might lead to an increase in the number of individuals using less safe cooking practices. Members also supported the recommendation to reiterate cooking of burgers advice, noting that some UK gourmet burger restaurants offered consumers the option to consume burgers which were rare (pink in the middle).

8.4 The Chair thanked Professor Williams for his update. Summing up she proposed that, in line with other ACMSF reports of this type, the document should be issued for a period of public consultation as soon as possible.
Action: Secretariat

ACMSF Report on infant botulism (ACM/780) and Listeria update
9.1 The Chair introduced paper ACM/780 and she reminded Members that at the June 2005 meeting the Committee agreed to publish its draft report on infant botulism for public consultation. This consultation took place between September and December 2005. She informed the Committee that the report was favourably received. The few comments received in response to the consultation were considered by the ad hoc Group and as a result several minor editorial amendments were made to the report. She therefore invited Members of the Committee to approve the revised report and also sought their agreement to submit the report to the FSA Chair for approval for final publication in the autumn. The Committee wholly endorsed these proposals.
Action: Secretariat

Listeria update

10.1 At the Chair's invitation Dr Jim McLaughlin (Health Protection Agency) presented updated information on human listeriosis in the UK in 2005. He reminded Members that the Committee was briefed on the changing pattern of human listeriosis in England and Wales from 2001-2004 in September 2005. He provided an overview of the information presented at that meeting. He also presented new information based on 2005 data summarising the incidence, clinical presentation and regional distribution of listeriosis in the UK.

10.2 Key conclusions arising from the presentation were that:

  • there was a continued increased incidence and altered clinical presentation of listeriosis reported in England and Wales in 2005;
  • there was a specific increase in 'sporadic' cases reported in North West England;
  • A similar situation had been observed in Scotland;
  • Collation of standardised epidemiology had continued
  • There was no evidence to suggest the reported increase in listeriosis was artefactual.
  • In 2005 one case of listeriosis was linked to sliced meats.

10.3 Members discussed the continued reported increase in listeriosis, and particularly in the elderly. Dr McLaughlin confirmed that the increase had occurred in almost every region compared with data for the 1990s (1-2 cases/million). Members acknowledged that the affected group covered a wide age range and suggested that more information was needed on the food purchasing and cooking habits of this group. The Committee also discussed the case of listeriosis in the north-west linked with sliced meats. Dr McLaughlin explained that the meat products were mainly sold in the north-west but also distributed nationally. However, since only one case was associated with sliced meats the epidemiological evidence was not strong. It was not possible to reach any conclusions regarding incidence linked to infective dose. Food consumption data was only available for

10.4 The Committee discussed whether the reported increase in listeriosis was artefactual. Dr McLaughlin confirmed that this was not the case as the organism had been isolated only from blood cultures (not central nervous system) obtained from the elderly population group. He added that the reported increase in listeriosis was also above that expected on the basis of current changes in demographic patterns.

10.5 The Chairman thanked Dr McLaughlin for his update. She noted that the Committee considered this was an important issue which required close review. She requested that the ACMSF receive a further update in December 2006 and that HPA include in this data for the first 6 months of 2006.
Action: HPA

Horizon scanning (ACM)782; EFIG; Hepatitis E
11.1 At the Chair's invitation Ms Tanya Green introduced paper ACM/782 which outlined the Agency's horizon scanning programme and sought views on suitable horizon scanning topics for consideration by the Committee. She summarised the Agency's key drivers for its horizon scanning activities and explained that she wished to observe how the ACMSF carried out its work on horizon scanning.

11.2 Dr Foster reminded Members that as the Committee had completed work on previously identified priorities it was timely to take stock and identify new topics for discussion. She invited Members to revisit topics previously identified for consideration in 2002 and to suggest new or emerging microbiological hazards which might merit attention by the Committee in the short to medium term.

11.3 In the ensuing discussion Members identified the following issues for consideration:

  • Difference in incidence of foodborne disease across the UK;
  • Imported foods in relation to antibiotic resistance and food as a source of ESBLs.
  • Noroviruses;
  • Food animal production ' specifically the importance of changes in usage of growth promoters in poultry production and its impact on microbiological flora. Members commented that flock health depression might impact on the gut flora;
  • Vulnerable groups - in light of previous discussions relating to listeriosis in the elderly population. Consideration needed to be given to microbiological risks to these groups in terms of disease and also the impact of changing patterns of food consumption and behaviour;
  • Impact of the drive for fresher products and milder processing conditions and novel processing techniques on food safety. Recent work carried out by the Committee examined thermal processing effects on Clostridium botulinum. Similar work could be considered for E.coli/>;

11.4 Summing up, the Chair requested that Members submit suggestions for horizon scanning topics to the Secretariat and that the Secretariat circulate a revised list to Members and that Members rank priorities for consideration.
Action: Secretariat


12.1 At the Chair's invitation, Dr Paul Cook (FSA) updated Members on the 9 March meeting of the Epidemiology of Foodborne Infections Group. He provided a synopsis of 2005 epidemiological animal data for Salmonella and human data for several pathogens including Salmonella, VTEC O157, Campylobacter and listeriosis. He also provided an update on two Agency egg surveys on non-UK eggs in retail premises and UK eggs in catering premises. Findings from a Defra prevalence survey of Salmonella in laying flocks in the UK which formed part of a wider EU survey were also outlined.

12.2 Dr Cook summarised a range of Campylobacter items that had been considered by the Group. These included a presentation on on-farm Campylobacter research by Professor Humphrey, updates on the National Case Control Study, Co-ordinated Local Authority Sentinel Surveillance of Pathogens (CLASSP), and a VLA Campylobacter survey. The Group also discussed recent surveillance carried out under the LACORS/HPA Food Liaison Group Co-ordinated Microbiological Sampling Programme. Lastly Dr Cook summarised brief updates received by the Group including a report on research on Hepatitis E and the Agency's survey of surveys.

12.3 The Chair thanked Dr Cook for his update. She requested that the Secretariat provide a short written paper rather than oral update on EFIG activities for future ACMSF meetings.
Action: Secretariat

Hepatitis E

13.1 At the Chair's invitation Dr Brown updated Members on issues raised in relation to discussions that took place at the December 2005 meeting on the risk to the food chain from Hepatitis E in pig meat products. He outlined an enhanced surveillance study in which a questionnaire approach had been used to try to identify risk factors. A case-control study had carried out. He explained that the researchers had been unable to identify any specific risk factors linked to Hepatitis E. He concluded that there was no new information to report to the Committee.

13.2 Dr Cook informed Members that the Agency had reviewed and changed its advice on cooking of pork in light of comments made at the December 2005 meeting. Current advice in the Safer Food Better Business Guidance would be update when the Guidance is reprinted. Dr Hilton added that advice for pregnant women the Eatwell web site did not require amendment.

Committee Sub-Groups
14.1 The Chair informed Members that there were three items to report other than those already covered in the agenda:

Working Group on Avian Influenza (ACM/783)

14.2 At the Chair's invitation, Dr Brown reminded Members that the ACMSF carried out a risk assessment for avian influenza in 2003. This assessment concluded that the risk of avian influenza from the food chain was low and that there was no evidence that the food chain was a route of infection. The assessment was reviewed in November 2005 in light of new information and the Committee concluded that there was no increased risk of avian influenza, although Members sought more information on control measures for poultry meat and eggs traded within the EU or imported from third countries. The Committee established a Working Group to examine control measures and keep a watching brief. This Group met in March 2006 and concluded that:

  • There was no new published scientific evidence to suggest that the food chain had a role in the acquisition of AI in humans.
  • Cooking precautions employed to avoid pathogens such as Salmonella in U.K. should also be sufficient to avoid avian influenza.
  • There were adequate control measures in place for poultry meat and eggs traded within the EU or imported from third countries. Surveillance of waterfowl is under review by Defra.
  • There were adequate systems in place to protect consumers from introduction of AI through the food chain.

14.3 The Chair thanked Dr Brown for his update and requested that the Secretariat made several editorial changes to the paper which would be provided by Dr Brown after the meeting.
Action: Dr Brown/Secretariat

Working Group on Surveillance

14.4 At the Chair's invitation, Professor Humphrey reported that the Working Group on surveillance met the previous day to provide advice to the Agency on aspects of survey structure and surveillance techniques and protocols. He explained that the Group had considered several Agency surveys including those on eggs, red meats, and listeria. The Group also received a presentation from FSA statisticians on survey organisation and sampling. The next meeting of this Group would take place in 6 months time.

Newly-emerging pathogens

14.5 At the Chair's invitation, Professor Hunter reported that there had been limited activity via the message board as no major threats to the food supply had been identified over the period in question.

Dates of future meetings (ACM/784)
15.1 The Chairman brought to Members' attention paper ACM/784 which listed the dates for meetings scheduled for 2006 and 2007.

Any other business

16.1 Professor Piddock sought information on which grant agencies were currently funding research on microbiology and foodborne pathogens and suggested that an annual update on this issue could be provided to the Committee.

16.2 Dr Hilton replied that the Microbiological Safety of Food Funders Group held a database which contained this information. These reports were used to identify any gaps in research. She suggested that the Secretariat circulated information on how to access the database to the Committee. She also requested that the Secretariat include Microbiological Safety Division's forward look on research document with the papers for the September meeting. Finally she referred Members to information paper ACM/788.
Action: FSA/Secretariat

Public questions and answers

17.1 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 observations.

17.2 Dr Simmons (consultant) outlined several issues relating to the safe cooking of burgers report. He commented that some of the text in paragraph 20 was repeated in paragraph 69. He added that the ACMSF's 1995 VTEC report had promised to revisit the safe cooking of burgers advice and welcomed the Committee's consideration of this issue. In relation to paragraph 69 of the report, he commented that there had been no UK foodborne disease outbreaks linked to fast food restaurants since the CMO's advice was introduced. This was also the case in North America, despite different time-temperature recommendations. He added that it was incorrect to lump together North and South America in the report, as there was a higher incidence of, and different risk factors for, E.coli O157 in South America. The Chair thanked Dr Simmons for his comments and invited him to respond formally to the public consultation on the report.

17.3 Mr Alan Proctor commented on the increase in Mycobacterium tuberculosis in the UK and queried whether beef cattle were screened for the disease. Professor Hunter explained that M. tuberculosis is a human pathogen. Mr Gayford confirmed that beef cattle were tested for TB (caused by M. bovis) and that meat from these animals was also tested for lesions at slaughter. Mr Proctor queried whether Mycobacterium bovis in cattle could also spread in humans. Mr Kyriakides replied that this issue had been addressed in a previous ACMSF report on Mycobacterium bovis.

17.4 Mr Rick Pendrous ('Food Manufacture' magazine) referred to the agenda item on vacuum and modified atmosphere packaging and commented that more work needed to be done to protect food safety in the supply chain, particularly in relation to temperature abuse of foods in retail stores. Dr Hilton replied that this was a risk management issue and therefore outside the Committee's remit. She added that the work in the report has highlighted some new information which the FSA would consider when it responds to the report. She also commented that the Safer Food Better Business Guidance contained advice addressing such issues.

17.5 Mr Sean Humber (Leigh Day and Co. solicitors) explained that he was representing members of HUSH and that his client had several concerns linked to the report of safe cooking of burgers. HUSH considered it unsatisfactory that an undisclosed company had lobbied the FSA for a review of the advice. HUSH also considered that all the information and evidence which contributed to the drafting of the report should be made publicly available to enable HUSH to comment on the report. He also commented that HUSH had not been invited to present evidence to the ad hoc Group. Other issues raised in relation to the work of the ad hoc Group related to who had provided the literature search and had carried out the modelling work, the number of E.coli D values related to E.coli from burgers, the number of E.coli infections (and source). Mr Humber also queried who would review the risk assessment and whether the Committee would consult on its report.

17.6 The Chair replied that the Secretariat had provided abstracts and papers for the literature research and that Members of the Group had also provided contributions. The modelling work presented in the report had been carried out by a student of Michigan University, as part of her Masters studies, under the direction of a member of the Ad hoc Group and other Unilever staff. Mr Bassett added that the model had used all available published E. coli data world wide in order to acquire the largest data set possible. Mr Bassett agreed to make this information availability to HUSH.
Action: Mr Bassett

17.7 Dr Foster explained that the Secretariat carried out the administration of all ACMSF consultations and collated responses on behalf of the Committee. The Chair explained that, as part of the consultation process, the consultation package would be sent to learned societies and professional scientific bodies for comment and that the ACMSF would take careful account of any responses arising from the consultation prior to formally publishing the report. She added that the other points he raised formed part of a Freedom of Information request and that Leigh Day solicitors would receive a formal response the following day.
Action: Secretariat

17.8 Mr Steve Batchford (Brakes) commented that the vacuum-packaged and modified atmosphere packed foods report highlighted differences in challenge testing and queried whether the 10 day rule would create barriers to trade. Dr Hilton replied that the FSA would consider this point when it examined the report.
Action: FSA

17.9 Mr Steve Nash outlined issues relating to unpasteurised milk noting that the Agency had provided guidance to milk producers which permitted sales of small quantities of milk (a crate a day) which did not have to meet certain standards. The Chair reiterated the view of the Committee that the ACMSF did not support the sale of unpasteurised milk. Mr Nash added that he would like to see information on costs and benefits in the ACMSF consultation on its safe cooking of burgers report. Dr Hilton commented that there would opportunity for Mr Nash to raise this issue in the form of a formal response to the ACMSF's public consultation on this report.

17.10 Ms Kaarin Goodburn (Chilled Food Association) outlined issues relating to listeriosis querying whether any account was being taken of the temperature and hygienic state of fridges. The Chair replied that this was an area of work that HPA might investigate.

17.11 Mr Tom Quigley (SFPB) commented that he supported the Committee's report on safe cooking of burgers, noting that with regard to the use of temperature probes, it was important not to place too much emphasis on these but to develop advice that empowered the consumer. He also outlined issues relating to the cooking of pork. He explained that, possibly as a result of differences in animal husbandry practices, pork could be cooked rare in the Republic of Ireland but not in Northern Ireland.

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