ACMSF Minutes: 19 January 2012

Meeting held at 1pm in Aviation House, 125 Kingsway, London WC2B 6NH.


Chair: Professor Sarah O’Brien

Dr Bob Adak
Mr John Bassett
Dr Roy Betts
Mrs Vivianne Buller
Professor John Coia
Professor Jim Gray
Dr Rick Holliman
Ms Jenny Hopwood
Professor David McDowell
Mr Paul McMullin
Mrs Jenny Morris
Mr David Nuttall
Professor Peter Williams

Departmental representatives:
Mr Stephen Wyllie (Defra)
Mrs Maggie Tomlinson (Department of Health)
Ms Liz Redmond (Food Standards Agency)

Ms Geraldine Hoad (Administrative Secretary)
Dr Paul Cook (Scientific Secretary)
Mr Adekunle Adeoye
Ms Sarah Butler
Dr Sophie Rollinson

Steve Batchford, Tesco
Bridgette Clarke, Bakkavor
Lyndon Davies
Bohumil Drasar
Roger Feldman
Caroline Goodburn, Florette
Kaarin Goodburn, Chilled Food Association
Alan Lyne, ADAS
Intisar Khan, Dairy Crest
Tom Miller, Retired consultant
Barry Mirhabib, Brakes
Rick Pendrous, Food Manufacture magazine
Ian Sheldrake, Matrix MicroScience Ltd
Karen Sims, Waitrose
Norman Simmons
Kara Thomas, British Retail Consortium
Michael Wood, Norpath Scientific

1. Chair’s introduction

1.1 The Chair welcomed ACMSF Members and members of the public, to the Committee’s 77th meeting. The Chair also welcomed Dr Andrew Wadge, FSA Chief Scientist, and Mrs Maggie Tomlinson as the new ACMSF departmental representative from the Department of Health.

2. Apologies for absence

2.1 Apologies for absence were received from Dr Sally Millership and Mrs Rosie Glazebrook.

3. Declarations of interest

3.1 The Chair reminded Members of the need to declare any conflicts of interest relating to items on the agenda. Prof Coia declared that in relation to agenda item 9 he provided occasional consultancy advice for Tesco who sold sprouted seeds. Ms Hopwood declared that her employer, Marks and Spencers, sold beansprouts. Dr Betts declared an interest as Campden BRI, his employer, have members who will sell beansprouts. Prof McDowell declared an interest in relation to agenda item 6 as he had carried out consultancy work for the British Hospitality Association. Mr McMullin declared an interest as a poultry veterinarian in relation to agenda item 11. Members were reminded to raise any other declarations of interest if the need arose during discussions.

4. Minutes of the 76th meeting (ACM/MIN/76)

4.1 As there were no comments on the minutes they were accepted as an accurate record of the last meeting and the Secretariat was asked to publish them on the ACMSF website.
Action: Secretariat

5. Matters arising (ACM/1047)

5.1 Ms Hoad drew Members’ attention to the summary of action taken on matters arising from previous meetings, highlighting that the Committees’ risk assessments on Mycobacterium bovis in milk and milk products and on raw cows’ drinking milk had been reported to the FSA Board in November. A policy paper on raw drinking milk was due for discussion by the Board in March. All other matters arising from the previous meeting had been actioned.

6. Horizon scanning (ACM/1048)

6.1 ACMSF discussed horizon scanning at their January 2011 meeting and identified four broad cross-cutting themes. It was agreed that changing food production techniques in the hospitality sector that may impact on microbiological food safety was a priority for consideration by the Committee. Mrs Buller and Mr Nuttall were invited to present the findings of an information gathering exercise they had undertaken on emerging issues in the catering sector to inform discussion on this topic.

6.2 Mrs Buller outlined the purpose of the exercise and explained how views were gathered from the catering sector by approaching a range of leading organisations with a number of questions on emerging issues. It was noted that the exercise therefore provided a snapshot of catering industry views rather than a fully representative survey.

6.3 Mr Nuttall highlighted some emerging themes from the consultation exercise, these included; concerns over the lack of guidance on sous-vide/water bath cooking, the use of vacuum packaging/gas flushing to extend shelf life, the effect of salt reduction on microbiological safety/shelf life, a trend to serve rare pork, the use of raw eggs in mousses and mayonnaise, norovirus contamination of shellfish, cross-contamination in catering businesses linked to Escherichia coli and undercooking of chicken livers for pâté. It was noted that many of the issues raised related to risk management and communication of existing food safety messages which were outside the remit of the Committee. Mr Nuttall concluded that the exercise had shown that reinforcing food safety messages and educating the public on risks from eating rare/undercooked foods may be required and that there was also a need for food safety guidance on sous-vide/water bath/slow cooking following introduction of these methods into the domestic market. It was also highlighted that these cooking techniques raise conflicting opinions amongst caterers and the food safety messages around these practices need clarifying.

6.4 In response to questions from the Committee Mrs Buller clarified that it was difficult to calculate the response rate as the questionnaire was passed to key contacts who were asked to forward it on to colleagues. Mrs Buller also clarified that, in terms of gaps in responses, they would have liked more feedback from the high end restaurant sector.

6.5 The Chair asked the Committee if they felt the exercise had highlighted anything they would need to look at in more detail. The following observations were made:

  • Many of the issues identified related to risk management rather than risk assessment and were for the FSA to take forward.
  • Data on the effects of lower temperature cooking on pathogens had not been looked at since the report on the safe cooking of burgers and could be revisited. There is also a potential resurgence in the popularity of beef carpaccio which may not have been previously considered by the Committee.
  • The issue of salt reduction and its effects on microbiological food safety was considered previously by ACMSF but a refresh on the discussions may be useful.
  • The current Ad hoc Group on Foodborne Viral Infections has considered information on norovirus in oysters which will be covered in their report.
  • There is a need for more information on water bath cooking to establish whether there are real concerns about their use and the evidence base for current advice on cooking practices should be reviewed.
  • There may be a need to look at consumer perceptions when eating in catering establishments, where customers may assume there are no risks for them.

6.6 In summarising the Chair identified three main issues that had emerged from discussions; extrapolation of data on pathogen survival at low temperature/time combinations (such as those used in water bath cooking), evidence on the microbiological safety of raw/rare foods and consumer perceptions of food safety when eating in catering establishments. It was suggested that a subgroup be formed to consider these issues in more detail and report back to the Committee. Mrs Morris, Ms Hopwood, Prof McDowell, Mrs Buller, Dr Betts and Mr Nuttall were nominated to participate in the subgroup. It was suggested that the first two topics could be combined and the third may require input from the Social Sciences Research Committee to review existing evidence.

Action: Secretariat and Members

7. ACMSF risk assessment (ACM/1049)

7.1 The Chair reminded members that they had welcomed the risk assessment framework used in the recently considered M. bovis in unpasteurised milk and milk products paper. In addition the ACMSF quinquennial review had recommended that the Committee should be more objective in presenting uncertainties in its risk assessments. The Chair invited Dr Cook to present a paper on ACMSF approaches to risk assessment which would assist in addressing these two issues.

7.2 Dr Cook explained that the paper was in two parts. The first part proposed a way forward and a framework for future ACMSF risk assessments. The second part provided some context to ACMSF risk assessments, explaining the different situations in which risk assessment was requested and how assessments were currently handled, including rapid ad hoc assessments. Dr Cook highlighted three areas that required consideration; the clarity of the risk assessment question, using the correct framework for assessment and reaching a common understanding in the way outputs were presented.

7.3 Members were in general agreement with the proposed approach and framework. It was noted that adopting a formalised approach does not have to increase the resources required as using a risk assessment framework can assist in clarifying the key issues. Some Committee members preferred to review external risk assessments rather than producing ACMSF risk assessments and suggested having the flexibility to put forward risk management options was useful, recognising that it is not in the Committees’ remit to make risk management decisions. It was cautioned that involvement of the committee in ad hoc incident risk assessments would need careful management to ensure this did not slow down the incident management process and to ensure as full a picture as possible is provided on incidents in order to assist with the Committees’ assessments. It was suggested that a formal risk assessment approach and a robust framework were particularly beneficial when uncertainty is greatest and data are lacking as this drives rigour in looking at the evidence and allows transparency in how any judgement on the level of risk is made. It was noted that the European Centre for Disease Prevention and Control (ECDC) have published recent guidelines on rapid approaches to risk assessment methodology.

7.4 The Chair summarised that members were supportive of the proposed approach and framework, recognising that different approaches were appropriate for different situations. The ACMSF, at present, were still in a situation where they produced their own risk assessments as well as reviewing external assessments. The Committees’ terms of reference, with respect to risk assessments, remained appropriate and did not need amending as long as the boundaries between risk assessment and risk management were clearly recognised. The Chair requested the ECDC guidelines be circulated to Members and asked the Secretariat to bring a paper on risk assessment output terminology to the next meeting for discussion.

Action: Secretariat

8. ACMSF response to the Waste and Resources Action Programme (WRAP) risk assessment on quality, safety and use of digestate in UK agriculture (ACM/1050)

8.1 The WRAP report on anaerobic digestate (AD) was discussed at the Committees’ September 2011 meeting. At that meeting it was agreed that a subgroup of Members would consider the report in detail and prepare a draft response on behalf of the Committee. Mr McMullin was asked to present the draft response for consideration and comment from Members.

8.2 Mr McMullin noted that, in general terms, there was nothing in the report the subgroup had disagreed with. It was felt the report dealt with most of the relevant food safety risks, focussing on those of greatest importance. The approach used was considered generally robust and where there was a lack of data a qualitative risk assessment approach was applied. However, the risk assessment outcome figures given in the report might imply a greater level of accuracy than was reasonable based on the data. The report concluded that, where products were produced in accordance with PAS100 standards, the risk was expected to be low, equivalent to less than 1 extra case of illness per year of the diseases considered. It was noted that pasteurisation is a useful control step but it was not clear from the report where the pasteurisation step should be applied and there was concern that some material could pass through the system without treatment, clarification of this issue was needed in the final report. Conflicting information was presented in some parts of the Clostridium botulinum section but the conclusion, that the overall risk was low, was considered reasonable. It was highlighted that C. botulinum is naturally present in the environment and goes untreated onto land. It is therefore unreasonable to expect a zero risk, and the issue is whether the potential risk through AD is any greater. The subgroup felt the risk management matrix worked well but had some particular concerns over untreated materials that may go onto crops which are not subject to further heat treatment, particularly in relation to Verocytotoxigenic E. coli. They also felt that those dealing with TSE issues should be made aware of the WRAP report, acknowledging that high risk material should not be present in digestates anyway.

8.3 Members made a number of comments on the proposed ACMSF response. It was noted that the presence of and difficulties in detecting unculturable bacteria/spores is an important issue that should be more clearly highlighted in the response. It was suggested that, in general, the response could be strengthened in several places particularly in relation to the importance of potential by-pass. The Defra representative highlighted that animal-by-product rules had been in existence for some time and the issue of AD and TSE risks may have been previously considered by the Spongiform Encephalopathies Advisory Committee (SEAC). It was also noted that, although by-pass is a critical issue, the opportunities for by-pass are limited compared to compost as AD uses a sealed system. The Defra representative undertook to confirm with colleagues whether SEAC had previously considered the issue.

8.4 The Chair requested that Members who had made specific comments on the draft response submit their amendments to the Secretariat and requested the Secretariat finalise the paper by correspondence before forwarding it to WRAP.

Action: Members and Secretariat

9. The microbiological safety of sprouted seeds (ACM/1051)

9.1 The Chair invited Ms Hoad to present paper ACM/1051 summarising recent activities in relation to the microbiological safety of sprouted seeds. Ms Hoad explained that the paper provided an update on activities following the Shiga-toxin producing Escherichia coli (STEC) outbreaks in France and Germany in 2011 and an outbreak caused by Salmonella Bareilly in the UK in 2010. The current FSA advice in relation to sprouted seed preparation for producers, caterers and the public was outlined, and it was highlighted that in Germany the advice goes further in recommending that vulnerable groups should only eat sprouted seeds that have been cooked. FSA enforcement advice for local authorities was also outlined. The European Food Safety Authority (EFSA) have recently issued a scientific opinion on the public health risks from contaminated seeds and sprouted seeds which Ms Hoad summarised. The Commission have proposed a number of potential control options for sprouted seeds which are currently under discussion. UK industry guidance on sprouted seed production is also under development. The Committee was asked to consider whether, in light of the actions taken, there is a residual risk of outbreaks associated with sprouted seeds and to comment on the relative risk compared to other fresh produce. ACMSF were also asked to advise whether some groups of consumers are particularly vulnerable to the risk of illness from sprouted seeds.

9.2 The Committee made the following comments in discussion:

  • A risk to human health does remain in sprouted seed production and outbreaks will continue to occur but the level of risk and likely frequency of outbreaks is difficult to quantify.
  • The outbreak due to S. Bareilly appears to have been associated with very low contamination levels that may not have been picked up by many laboratories and this issue also needs consideration.
  • It was suggested that the distinction between ‘ready to wash’ and ‘ready to eat’ sprouted seeds may not be recognised by consumers and the different advice in relation to these products and the variety of guidance on sprouted seed packaging could be confusing. It was clarified that ‘ready to eat’ means the product has been washed commercially.
  • It was highlighted that it is difficult for consumers to take protective food safety steps in relation to sprouted seed consumption especially when eating out. It was also noted that if advice to vulnerable groups was issued this would not be inconsistent with existing food safety advice for immunocompromised individuals and fresh produce. It was considered that advice to cook sprouted seed until piping hot may have limited practicality as the product loses its crunchy texture.
  • Adult women are the highest risk group for outbreaks linked to sprouted seeds probably because they have the highest exposure.
  • The application of seed irradiation as a control step was briefly discussed.
  • It was suggested the issue may need broadening to include consideration of sprouting seeds for animal feed and ACAF may have an interest in this.
  • Dr Wadge clarified that the Agency needs a qualitative sense of how important the risk from sprouted seeds is compared to other food related risks to help inform negotiations on control options and consumer advice.
  • Ms Redmond provided a summary of the proposed Commission controls for sprouted seeds. These included requirements for irrigation and washing water, approval of establishments, traceability, microbiological food safety criteria and import controls/certification.
  • Concerns were raised over the use of microbiological criteria as a control measure as these cannot guarantee the safety of a product. It was noted the suggestion is for these to be applied as part of a food safety management system.
  • It was highlighted that the Committee had not seen the evidence that underpins the proposed control options and would need to look at this data in more detail in order to be able to comment on and rank the most effective control options.

9.3 In summarising the Chair noted there was no disagreement in principle with any of the proposed controls for sprouted seeds but the Committee had not been able to review all the relevant data so were not in a position to rank the risks from sprouted seeds relative to other food safety risks. A teleconference was proposed to discuss the issue further and provide advice to the FSA by the short deadline required. Ms Hopwood, Prof McDowell, Mr Basset, Dr Betts and Prof Coia were nominated to participate in the teleconference.

Action: Secretariat and Members

10. ACMSF Work plan (ACM/1052)

10.1 The quinquennial review of the ACMSF made a recommendation that the Committee should improve the process for determining its work programme and publish a forward workplan. Dr Rollinson introduced paper ACM/1052, outlining a proposed process for agreeing a workplan with the Committee, periodically reviewing and updating the plan and publishing it on the ACMSF website. Two alternative formats for the ACMSF workplan were presented, one with items presented for each meeting chronologically and one with items presented by topic, giving an indicative timescale for consideration. It was noted that the workplan would be a living document with the flexibility to be amended and updated as the Committee frequently dealt with reactive issues that arose at short notice. Members were asked to comment on and approve the process for agreeing the workplan and indicate which draft format they preferred.

10.2 Members agreed the second workplan format was preferable, with items presented by topic, as this would be easier to update and would give a broader overview of topics to be considered. It was confirmed that the Secretariat would update the workplan between Committee meetings and provide the plan as a standing item information paper at meetings. It was suggested that the workplan include information on the expected output for each item to be considered and also the outcome of any Committee reports or advice.

10.3 The Chair asked the Secretariat to make the suggested changes to the workplan and noted that presenting items by individual topics was the Committee’s preferred format.

Action: Secretariat

11. EFIG (ACM/1053)

11.1 Dr Cook was invited to update Members on the outcome of the Epidemiology of Foodborne Infections Group (EFIG) meeting which took place on 10 November 2011. Dr Cook outlined the key points from the 2011 animal data, noting that reports of Salmonella associated with animals were lower than in previous years. Of the monophasic Salmonella Typhimurium reports DT193 was the predominant phage type. Monophasic strains had become more frequent in pigs over last few years. An Animal Health and Veterinary Laboratories Agency study to characterise monophasic strains using genome sequencing will be presented to EFIG at a future meeting. In terms of human data laboratory reports of Campylobacter continued to increase in 2011 and reports of Listeria monocytogenes continued to decline. There was an increase in VTEC O157 PT8 reports which was mainly attributed to the 2011 outbreak associated with leek and potato sold loose. EFIG also discussed the results of a study in Wales to look at the Campylobacter sampling rate and positivity rate over a number of years which suggested that the rise in incidence up to 2008 may be in part due to a sampling artefact but the 2009-10 data could not be explained by an increase in sampling rate alone. The number of Campylobacter outbreaks per year now exceeds the number of Salmonella outbreaks, with chicken liver pâté the most commonly attributed food vehicle. EFIG also received updates on the second Infectious Intestinal Disease study, Defra’s antimicrobial resistance co-ordination group, FSAs official controls review and HPA food, water and environment microbiology laboratories work, including an ongoing survey of lightly cooked food such as chicken liver pâté and sous-vide products.

11.2 Members made a number of comments on the EFIG update:

  • The lack of denominator data was raised and it was noted this makes interpretation of the animal and human data presented difficult. It was highlighted that some of the animal data comes from reactive incidents and some from national control plan sampling and it is therefore difficult to know what to set as the denominator data. Defra do publish separate detailed Salmonella data annually. Similarly, for the human data potential denominators could include samples taken or presentations to GPs but this type of data is not readily collected. The FSA representative noted that EFIG had considered ACMSF’s request for denominator data at previous meetings and discussed the issue at length but is a very difficult problem to resolve and in some cases investment would be needed to gather the data. The issue was however on EFIG’s horizon.
  • The level of precision quoted in some of the animal data estimates may not reflect the confidence that can be placed in the estimate given the sample size and the lack of denominator data.
  • No information on the number of Campylobacter outbreaks was presented. It was noted that Salmonella outbreaks have decreased over recent years and Campylobacter outbreaks have increased but Salmonella outbreaks tended to be bigger.
  • It was highlighted that the number of Listeria reports is continuing to decrease and there may be a benefit in trying to understand why.

11.3 In summarising the Chair noted that ACMSF should continue to press for denominator data from EFIG, recognising the inherent challenges in this. There was also a difficulty in understanding the confidence around the estimates presented and knowing if the reported increases or decreases were statistically significant.

12. Code of Practice for Scientific Advisory Committees (ACM/1054)

12.1 Mr Adeoye was invited to introduce paper ACM/1054 on the 2011 revised Code of Practice for Scientific Advisory Committees (CoPSAC). Mr Adeoye noted that the revised CoPSAC had now been published and was intended to provide a guidance framework for scientific advisory committees and interaction with their sponsoring bodies. Although the Code had been restructured there were no substantial changes to the guidance. The revisions addressed ambiguities and gaps identified through the consultation exercise. The new entries and changes under each chapter were highlighted for Members who were invited to note the amendments concerning the role and responsibilities of the Chair, Members, Secretariat and Departmental Representatives.

13. Committee sub-groups

13.1 Professor O’Brien provided an update on the October 2011 meeting on the Ad Hoc Group on Foodborne Viral Infections. At the meeting the group had considered a presentation from AHVLA on a study into Hepatitis E in pork products and also reviewed HPA surveillance data on Hepatitis E in the human population. The findings of the Cefas study into the prevalence, distribution and levels of norovirus in oysters in UK was also discussed and the EFSA scientific opinion of foodborne viruses was reviewed. The group’s next meeting will consider emerging viruses, after which the group will begin drafting their report.

14. Dates of future meetings (ACM/1055)

14.1 Members were asked to note the dates of the 2012 ACMSF meetings on 29 May and 27 September.

15. Any Other Business

15.1 Dr Cook updated Members on a workshop on the application of molecular epidemiology in outbreak investigations that had taken place on 17 January. The workshop was organised in collaboration with HPA, BBSRC and Members of ACMSF. The aims were to explore new ways to identify and control outbreaks using newer techniques in molecular epidemiology, to see how these could assist traditional approaches. The strengths and limitations of various approaches were identified with particular focus on next generation sequencing and how this could be deployed, including resource considerations. It was noted the workshop was a useful and timely meeting that identified a number of advantages and obstacles going forward including bioinformatics challenges and organisational ones. A report of the workshop would be available on the FSA website in due course.

15.2 The Chair provided Members with an update on the latest meeting of the General Advisory Committee on Science (GACS). Items discussed at GACS included a presentation on the work of ACMSF by the Chair. The importance of maintaining a dialogue with the Scientific Advisory Committee on Nutrition (SACN) was raised in terms of recommendations they make which may impact on food safety. Other items discussed at GACS included the quinquennial reviews of ACMSF and COT, a framework for sharing data with industry and NGOs which may help inform risk assessment, and a presentation on the WHO influenza surveillance system.

16. Public Questions and Answers

16.1 The Chair drew formal proceedings to a close and invited questions and comments from the public.

16.2 Dr Norman Simmons (ex-ACMSF Member) considered that the current FSA advice on sprouted seeds was misleading and the Committee should highlight this to the FSA. Many seed lots tested were found to have bacterial contamination and there are no processes known at this time that would render seeds safe, therefore there is a chance that an outbreak will occur in the UK. Sprouts are a risky product, particularly if eaten raw and the risk varies in different countries. Dr Simmons noted the importance of epidemiology in potentially limiting the size of outbreaks and suggested that the importance of a national epidemiological organisation should be highlighted to Government.

16.3 Prof Roger Feldman (ex-ACMSF Member) commented that when seeds germinate they produced a large number of bacteria which was a problem that cannot be ignored in a product that isn’t cooked. Dr Feldman noted parallels with the consumption of hamburgers in the US in the 1980s and the subsequent E.coli O157 outbreaks. The FDA are currently writing regulations in relation to sprouted seeds and chlorine washing is being considered as a possible way of reducing the amount of bacteria on sprouts but there is a large range of different organisms that may be present on sprouts including E.coli, Salmonella and Listeria.

16.4 Mr Tom Miller (retired food catering technologist) highlighted that the summary of the report on norovirus in oysters (ACM/1060), had a section that was not clear on the FSA website, highlighting that the oysters investigated were not ready-to-eat. He suggested a follow-up on ready-to-eat oysters would be beneficial as this would be of more use to the public and the hospitality sector. Mr Miller also noted it was disappointing that two of the major issues identified in the catering horizon scanning presentation were diverted to an issue of consumer behaviour in the home rather than catering industry practices. Mr Miller suggested that vacuum packaging and microbiological food safety, in terms of extending shelf-life, was an issue that did need to be looked at further. Mr Miller also noted that it appeared that it was now commonplace for burgers in restaurants to be cooked medium rather than well done. There was no mention of this in the catering horizon scanning presentation and it was suggested this was a potentially serious unrecognised problem. The Chair noted that the Committee did not want to give the impression that they were trying to pass issue over as consumer problems and that focussing on the catering industry as well was extremely important.