ACMSF Minutes: 20 January 2011

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


Chair: Prof S O’Brien
Mr J Bassett
Mrs V Buller
Prof J Coia
Mrs R Glazebrook
Dr R Holliman
Prof T Humphrey
Prof P Hunter
Mr A Kyriakides
Prof D McDowell
Mr P McMullin
Dr S Millership
Mr D Nuttall
Prof P Williams

Ms L Redmond (FSA)
Mr S Wyllie (Defra)

Officials in attendance:
Ms E Pengilly (FSA)

Ms G Hoad (Administrative Secretary)
Dr P Cook (Scientific Secretary)
Mr A Adeoye
Ms S Butler
Dr S Rollinson

Invited experts:
Dr N Strachan (University of Aberdeen)
Professor J Farrington (University of Aberdeen)
Professor D Rigby (University of Manchester)

Members of the public:
Bob Adak, Health Protection Agency
Steve Batchford, Brakes
Roy Betts, Campden & Chorleywood BRI
Keneth Chinyama, Food & Drink Federation
Bridgette Clarke, Bakkavor
Catherine Cockcroft, Exova
Jenny Hopwood, Marks & Spencer
Helen Kendall, PhD student
Helen Lucas
Barbara Lund
Ishbel Mackinnon, HUSH
Barry Mirhabib, Brakes
Tom Miller, National Consumer Federation
Rick Pendrous, Food Manufacture magazine
Bernard Rowe, Consultant
Karen Sims, Waitrose
Ian Sheldrake, Matrix MicroScience limited
Nicola Wilson, Samworth Brothers
Michael Wood, Norpath Scientific Services

1. Chair’s Introduction

1.1 The Chair welcomed ACMSF Members and members of the public to the 74th meeting of the Committee. The Chair also welcomed Ms Emma Pengilly (FSA) who would be presenting agenda item 6, Dr Norval Strachan (University of Aberdeen), Professor John Farrington (University of Aberdeen) and Professor Dan Rigby (University of Manchester) who would be presenting agenda item 9.

2. Apologies for absence

2.1 Apologies for absence had been received from Mrs Jenny Morris and Dr David Brown.

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, both at the beginning of the meeting and subsequently if the need arose during discussions. Prof Paul Hunter raised a conflict of interest on item 7 as he had received funding from Danone [beverages] to attend scientific meetings, Danone also manufacture dairy products. Mr Alec Kyriakides declared a conflict of interest on item 8 as his employer sells products of the type under discussion. Prof Tom Humphrey declared a conflict of interest in relation to item 8 as he carries out research in this area with some projects funded by FSA. Mr Paul McMullin declared a conflict of interest in relation to discussions under item 12 as a poultry veterinarian.

4. Minutes of the 73rd meeting

4.1 Members approved ACM/MIN/73 as a correct record of the previous meeting subject to a minor amendment to paragraph 18.1 to correct the accuracy of Mr Tom Miller’s comments in the public questions and answer sessions. The Secretariat was asked to arrange for the final minutes to be posted on the Committee’s website.
Action: Secretariat

5. Matters arising

5.1 Ms Geraldine Hoad summarised the actions taken on matters arising from previous meetings (ACM/1006). In relation to the action to check for recent data on “D” and “Z” values for High Temperature Short Time treatment of milk Ms Hoad agreed to provide the derived “D” values from the Kells & Lear paper to Mr Kyriakides. There were no comments on paper ACM/1006.
Action: Secretariat

6. Horizon Scanning

6.1 The Chair introduced this item, explaining that a number of potential horizon scanning topics had been discussed at the previous ACMSF meeting in September. Mr Kyriakides, Ms Buller, Mr Bassett and Prof McDowell had subsequently met to consider the topics in more detail and report back to the main Committee. To complement the Committee’s discussions on horizon scanning a presentation on the Agency’s ongoing work to identify emerging risks would also be given and both items discussed together following the presentation.

6.2 Mr Kyriakides presented paper ACM/1007 reporting on the group’s horizon scanning meeting. The group initially considered the merits of an organism specific approach versus a broader approach to identification of horizon scanning topics. They decided that a broader look at underlying technological factors that would affect microbiological risks in the future was most appropriate given that no significant changes that would merit an organism specific approach were identified.

6.3 The 4 horizon scanning topics identified by the group, in priority order, were:

  • changes in food preparation practices in the kitchen, catering and retail;
  • agricultural changes focussing on the primary agricultural sector;
  • globalisation of food sourcing and production;
  • food processing and production changes at a manufacturing level.

6.4 The group considered that changes in emerging pathogens and demographics would be picked up by the Committee’s Working Groups on Emerging Pathogens and Vulnerable Groups respectively. These areas were therefore not identified as separate horizon scanning topics. The Committee was recommended to consider one or more of the four topics in depth to identify specific emerging issues which might require further consideration.

6.5 Ms Pengilly introduced work the Agency is piloting which aims to make better use of existing intelligence to identify trends in food safety risks using a National Intelligence Model to collate and manage information from various sources. Trends in food safety incidents can be measured against a baseline of stable data from recorded incidents in previous years. Although microbiological incidents as a category were not identified as one of the fastest growing emerging risks there had been an increase in such incidents over the last 4 years which is predicted to continue in the next few years. A spike in microbiological incidents in early 2010 due to norovirus contamination was highlighted. Analysis of Rapid Alert System for Food and Feed (RASFF) reports showed a number of more specific microbiological hazards where RASFFs had been increasingly raised including parasites in fish, Listeria in fish products and Salmonella in fruit and vegetables.

6.6 The Committee made a number of comments on the emerging risks presentation including the need to build in evaluation of the work to assess whether the pilot was working effectively. In response to a query on how intelligence from members of the public was captured Ms Pengilly explained that one of the intelligence sources included in the work was the Memex database where evidence on food fraud from a range of sources, including the public, was recorded and assessed.

6.7 The Committee supported the broader horizon scanning approach outlined in paper ACM/1007 and the four horizon scanning topic identified. However they noted that the topics raised were very broad and a way of focussing these down was required. It was noted there was no mention of regulatory changes and subsequent unintended consequences and it may also be useful to formally capture at what stage in the food chain specific horizon scanning issues arise.

6.8 In summarising the Chair noted there was agreement from the Committee on the horizon scanning topics proposed and in taking this work forwards there may be need to draw on the expertise of other Advisory Committees. Paper ACM/1007 was recommended for submission to the FSA.
Action: Secretariat

7. Raw Milk

7.1 Ms Hoad was invited to present paper ACM/1008 seeking the views of the Committee on the health risks to consumers associated with unpasteurised milk and cream for direct human consumption. Ms Hoad explained the FSA Board had raised concerns over the proportion of raw cows’ milk samples failing microbiological testing criteria in a recent Operations report and requested the FSA review current evidence on the safety of raw milk for direct human consumption. Information on human illness, microbiological quality, market data and current legislation in relation to raw milk and cream was provided in the paper. It was noted that on previous occasions when the ACMSF has considered data on the safety of raw drinking milk the Committee has stressed the importance of pasteurisation in the protection of human health.

7.2 Data from the Health Protection Agency on outbreaks of Infectious Intestinal Disease (IID) due to raw milk and cream were summarised. Outbreaks of human illness due to raw drinking milk between 1992 and 2002 represented a small proportion of the total number of reported foodborne outbreaks during this period. No outbreaks of IID due to raw milk or cream had been reported in the last eight years suggesting the burden of disease from these sources had declined, although under-reporting of outbreaks and likely sporadic cases of illness were acknowledged.

7.3 Microbiological surveys carried out over last 15 years on raw milk and cream from cows and other species showed that pathogenic microorganisms were present in some raw milk samples and indicators of faecal contamination were present at varying levels in most samples. Data from the statutory quarterly monitoring of raw cows’ milk for compliance with microbiological criteria was also summarised as this provides a useful indication of the quality of raw cows’ drinking milk. The level of sample failures had remained fairly constant over the last 7 years, as the number of samples tested had declined probably due to a decline in production. It was noted that the total number of failures included re-samples from farms which failed the criteria and, therefore, a small number of farms consistently failing can skew the failure rate.

7.4 Areas where data were lacking included information on sales volumes, which made it difficult to assess the level of human exposure, recent surveillance data on the frequency of pathogenic contamination of raw milk and cream and microbiological quality data from species other than cows. The Committee was requested to consider if the data presented were sufficient to assess the current risks to human health and, if so, to review its previous assessment of the risks to consumers from consumption of raw drinking milk and to consider raw cream.

7.5 In the ensuing discussion the Committee noted that:

  • Much of the data presented were old and due to data gaps in many areas a robust and specific risk assessment was difficult. The epidemiology has probably changed in terms of overall consumer exposure through consumption of raw drinking milk. The risk to the individual was likely to have remained the same and was considered non-negligible, as before, but it was not possible to quantify this based on available data.
  • No new data was presented which would justify a change from the Committee’s current position and there was no new evidence to suggest raw milk and cream were safer than previously.
  • The lack of recent reported outbreaks of human illness linked to raw milk could possibly be as a result of reduced exposure to raw milk and cream. New sales routes, such as internet sales and farmers markets, could make identification of outbreaks less likely as raw milk and cream consumers would be more widespread.
  • The presence of faecal contamination in raw milk was apparent from the current data presented on the microbiological quality of raw milk and the link between faecal contaminants and the presence of pathogens has been demonstrated.
  • More information on consumption levels and in particular on new sales routes such as internet sales would assist in assessing whether the level of risk had changed. Data from the HPA’s enhanced surveillance for E. coli O157 infections might also provide some relevant information. However, it was also noted that further data are only needed if a more precise estimate of risk is required.

7.6 In summarising the Chair noted that, given the evidence presented, the Committee did not feel a need to change its recommendation that pasteurisation is an important control measure in reducing the risks from consumption of raw milk. Additional data gathering may help give a more accurate assessment of risk if desired. If data on changing sales routes is gathered there may be a need for the Committee to review the risks from raw drinking milk.
Action: Secretariat

8. Chicken liver pâtés

8.1 Prof Humphrey presented paper ACM/1009 on Campylobacter and chicken liver pâté. Prof Humphrey noted that Campylobacter was traditionally recognised as a cross-contamination risk but the risk from Campylobacter in muscle tissue and livers should be considered equally important. Data on the presence of Campylobacter in muscle tissue and liver were presented including research from New Zealand where 27 out of 30 chicken livers examined were contaminated internally with Campylobacter, some with greater than 1100cfu/100g. The same study looked at the effect of time and temperature on survival of Campylobacter in the livers and showed no meaningful reduction in numbers of bacteria until approaching 70°C. It was suggested that flash fried livers were unlikely to reach this temperature internally.

8.2 Data on the effect of hot water treatment on Campylobacter numbers on chicken carcasses was also presented. Immersion in hot water did not result in any meaningful reduction in numbers, and it was suggested hot water treatments may only remove organisms which are not well attached. It was also highlighted that chilling Campylobacter leads to a small but significant increase in its resistance to heat.

8.3 Chicken livers may become contaminated with Campylobacter during the slaughter process but it was also suggested livers may become contaminated during the lifetime of the bird as it is known that some strains of Campylobacter are invasive and cause a vibrionic hepatitis in birds. The association between Campylobacter infection and bird welfare was discussed, including data that showed extra-intestinal spread of Campylobacter in immunosuppressed broilers and those co-infected with Avian Pathogenic E. coli. Prof Humphrey concluded there was a need to understand risk factors better, particularly the production environment, and mechanisms for the extra-intestinal spread of Campylobacter and to properly examine the resistance of Campylobacter to heat and other stresses.

8.4 The Committee asked a number of questions following the presentation. In response to queries on the effects of freezing on Campylobacter and the implications of the research presented on the current cooking recommendations Prof Humphrey confirmed that freezing kills most of the Campylobacter present in a sample and evidence suggests it was still the case that cooking at 70°C for 2 minutes will destroy any Campylobacter present. Dr Cook also confirmed that current FSA advice was that a core temperature (as opposed to an external temperature) of 70°C for 2 minutes (or an equivalent time/temperature) should be reached when cooking. Prof Humphrey confirmed that, in the slaughterhouse study, C. jejuni rather than C. coli was isolated from contaminated livers suggesting C. coli was better confined to the chicken gut than C. jejuni.

8.5 Further discussion suggested that there may be some confusion amongst consumers in how to prepare different cuts of meat and offals from different species and the appropriate cooking recommendations to follow. It was suggested that chicken liver should be considered in the same way as a comminuted product.

8.6 The Chair summarised discussions noting there was a need to understand more about Campylobacter and chicken liver contamination. Cooking liver to a core temperature of 70°C for 2 minutes should kill the Campylobacter present but there may be a need to consider liver as comminuted meat rather than a whole meat in the context of delivering appropriate food safety messages.

9. Rural Economy and Land Use (RELU) Programme

9.1 The Chair invited Dr Strachan, Prof Farrington and Prof Rigby to present the findings of their research under the RELU programme.

9.2 Dr Strachan introduced the presentation and the research approach taken. The work aims to integrate the social and natural sciences to research reducing the E. coli O157 risk in rural communities focussing on two study areas, N. Wales and Grampian. Dr Strachan summarised the studies on E. coli O157 survival in soil, noting that organism numbers decreased rapidly during the first few days and no differences were found in survival in different soil types. Recovery studies showed organism reactivation was seen more strongly at lower temperatures. Measurement of E. coli O157 serum antibody levels in the study areas showed around 5% of farmers, abattoir workers and rural and urban residents tested were positive. A regression model and risk assessment were used to predict the mean number of E. coli O157 cases attributed annually to different transmission pathways in Grampian, these approaches attributed 27% and 56% of cases to food respectively.

9.3 Prof Farrington presented the public awareness work undertaken involving a questionnaire survey of 2,000 farmers, residents, visitors and abattoir workers in the study regions. These results demonstrated a wide awareness of E. coli O157, particularly in high disease incidence areas although there was a generally low awareness of bloody diarrhoea as a symptom. Strong opinions around belly clipping recommendations were highlighted in several questionnaire responses from farmers.

9.4 Prof Rigby presented the findings of a consultation with farmers and the public to investigate the perceived risk from E. coli. E. coli was found to be a relatively high worry risk as articulated by people, higher than other food related worries such as GM, BSE and bird flu. Work was also undertaken to assess the practicality and effectiveness of measures to control E. coli O157 as ranked by experts and farmers. Some interventions such as vaccination were ranked as potentially highly effective by experts but not by farmers and others, such as pre-slaughter removal of high shedders, were considered more practical by farmers than experts. However, no single ideal intervention was identified by this expert elicitation.

9.5 The Committee had a number of questions for the presenters:

  • Mr Stephen Wylie (Defra) asked whether any interventions generally considered effective were ranked with a low efficacy and practicality by experts. Prof Rigby responded that there is evidence from systematic trials for the effectiveness of dry bedding and double fencing as E. coli O157 control measures but these were both given a low score by experts.
  • In response to questions on the soil survival experiments Dr Strachan clarified that 8 different soil types were tested and also clarified that other factors that might influence survival in soil, such as protozoal ingestion were not investigated.
  • In response to a query on whether a static or dynamic model of exposure was used in the risk assessment Prof Strachan clarified that the model assumed an individual was exposed only once i.e. a static model was used. In order to attempt to capture accumulated exposures the model was run over several iterations over a long period of time to see if consistent results were returned.

9.6 The Chair thanked the presenters for an interesting talk on the RELU programme and noted the work would raise some interesting outcomes for risk managers.

10. Committee sub-groups

10.1 Prof Hunter provided an update on a meeting of the Working Group on Newly Emerging Pathogens which had met to consider Bovine Neonatal Pancytopaenia (BNP). BNP is a newly emerging haemorrhagic disease, first reported in May 2009 which primarily affects very young calves, resulting in substantial internal and mucous membrane bleeding and associated with a very high mortality rate. The syndrome has been reported in several countries across Europe including the UK. The Group received a presentation from the Veterinary Laboratories Agency (VLA) on investigations into the syndrome.

10.2 The Group were asked to assess any foodborne risks from products from affected calves and cows based on the available knowledge. The Group were not in a position to come to a definitive conclusion due to the lack of information on which to make a judgement. The primary hypothesis for the cause of the syndrome relates to transfer of specific maternal antibodies through the colostrum of some cows to their calves. If this hypothesis is correct the risk to humans from the food chain must be low. However, the Group were aware that studies investigating the hypothesis were close to completion and they therefore wished to reserve their judgement until further information was available and they can meet again to assess this.

10.3 In the absence of the Chair of the Ad Hoc Group on Foodborne Viral Infections Prof O’Brien provided an update on the first meeting of the Group. The Group had agreed to focus their discussions on Norovirus, Hepatitis A and E and other new and emerging foodborne viral pathogens. A framework for assessing the foodborne risks from viruses will be defined, giving consideration to the WHO foodborne virus matrix. The Group agreed to liaise with the European Food Safety Authority (EFSA) technical panel currently considering foodborne viruses and also to review actions taken to address the recommendations made in the 1998 ACMSF report on foodborne viral infections. The next meeting of the Group is expected to focus on relevant results from the Second Infectious Intestinal Diseases (IID2) study. Prof O’Brien outlined the draft Terms of Reference for the Group noting they plan to finalise the report for consideration by January 2013 at the latest.

11. Openness

11.1 The Chair reminded Members that the possibility of holding open meetings of ACMSF Working and Ad Hoc groups had been discussed at the December 2009 Committee meeting. The Committee had, in principle, welcomed the commitment to greater openness but highlighted a need to ensure flexibility so that discussions were not inhibited and the quality of advice given to the Agency was not affected. The Committee had recommended the Secretariat consider the practicalities of a move to more openness.

11.2 Dr Sophie Rollinson was invited to present paper ACM/1012 outlining a suggested approach for increasing the openness of ACMSF sub group meetings. Dr Rollinson explained that after reviewing procedures and openness of similar Committees the Secretariat proposed that:

  • Meetings of Working and Ad Hoc groups will continue to be held in reserved business and a written summary of these meetings will be prepared for presentation at the following main Committee meeting. This summary will be published on the ACMSF website.
  • A webpage is developed for all existing Working and Ad Hoc Groups to include information on their terms of reference, membership and meeting summaries. Minutes of subgroup meetings will be published on these pages once a Group’s final report is published.
  • Authors of papers that contain pre-published material and commercially sensitive information will be made aware of how the Group will handle this information and how the FOI Act applies to the Committee.
  • These new procedures are implemented for the next scheduled meeting and reviewed in 12 months.

11.3 The Chair invited comments on the proposals. The Committee considered the proposals were workable and practical and would make the deliberations of Working and Ad Hoc groups more transparent. The Committee endorsed the proposals outlined.
Action: Secretariat

12. Epidemiology of Foodborne Infections Group (EFIG)

12.1 Dr Paul Cook introduced paper ACM/1011 providing an overview of the November 2010 EFIG meeting. EFIG discussed feedback from the ACMSF in terms of the request for information on trends and summaries of EFIG data, supported by figures and denominator data where possible. It was noted that provision of denominator data for animals was challenging as the data was based on reported isolations or incidents which have a broader scope than for human isolations. There were also issues with using laboratory submission or animal population data as denominators. It was noted that EFIG would shortly consider a paper on animal denominator data and what information could be usefully provided.

12.2 Other items highlighted from the EFIG meeting included the January to June 2010 Salmonella in livestock reports and human pathogen data for January to September 2010. Reports of S. Enteritidis and S. Typhiumurium in livestock remained low and monophasic Salmonella 4,5,12:i:- continued to be isolated. Incidence rates for Salmonella in humans continued to decline whilst Campylobacter incidence was continuing to rise. Rates for E. coli O157 and L. monocytogenes in humans were lower in the first 9 months of 2010 than for the corresponding period last year. EFIG also considered a paper on possible reasons for the rise in Campylobacter cases which concluded the rise was likely to be real rather than due to changes in sampling and reporting. It was suggested that possible ways to investigate the issue further were to look at changes in MLST types, hospital bacteraemias or through sentinel surveillance based on existing networks. A scientific opinion on monophasic S. Typhimurium had also been published by EFSA in September 2010 which considered the public health risk from these strains.

12.3 The Committee made a number of comments on the paper

  • It was noted that the reduction in the L. monocytogenes incidence rate in humans appeared significant and comparison with EU data was raised. Dr Cook responded that the figures represented low numbers so should be interpreted with caution but if the cases continued to decline they would be at the levels seen before the recent “spike” in listeriosis. Dr Cook was not aware of the recent figures for other EU countries.
  • It was suggested that MLST typing Campylobacter from hospital bacteraemias would not give representative information on all human Campylobacter cases and may not help in understanding the recent general rise in Campylobacter cases.
  • It was also noted that weather conditions over the last 12 months have been quite unusual and the freezing temperatures may have had an effect on Campylobacter in poultry. FSA may need to consider this in discussions with its researchers.

13. Dates of Future Meetings

13.1 Members were asked to note the dates of 19 May and 22 September for the 2011 ACMSF meetings.

14. Any Other Business

14.1 The Chair reminded Members of concerns raised at their last meeting on the implications of Health Service reorganisation on the Committee's accessibility to robust surveillance data. The Department of Health White Paper was published for consultation in November 2010 and the Chair suggested Members send any consultation comments to Peter Williams and herself to produce a co-ordinated consultation response from the Committee.
Action: Members

14.2 The Chair provided Members with an update on the latest meeting of the General Advisory Committee on Science (GACS). Items discussed at GACS included the effect of the spending review and change in FSA remit on Agency research, the move of the Scientific Advisory Committee on Nutrition (SACN) to the Department of Health, a report from the risk assessment/risk management Working Group and a review of the Agency’s commissioned work on the nutrient content of organic and non-organic foods.

14.3 The Chair informed Members that this was the last Committee meeting for Mr Kyriakides, Prof Humphrey, Prof Brown and Prof Hunter whose ten year term on ACMSF ends in March 2011. The Chair thanked them for the hard work, wisdom, support and commitment they have provided to ACMSF.

14.4 The Chair informed Members that the ACMSF was undergoing a quinquennial review by the FSA and a number of Members and stakeholders had been selected for interview by the reviewer. Anyone else wishing to be involved in the review should contact the Secretariat.

15. Public Questions and Answers

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

15.2 Mr Tom Miller from the National Consumer Federation referred to information paper ACM/1014, on outbreaks of infection caused by ready to eat food, noting that he hoped the issues raised in this paper were fully addressed by the FSA. These included issues around Salmonella in duck eggs, Listeria in retail meat and Campylobacter in chicken liver pâté. Mr Miller suggested there was a need for the FSA to be robust in giving food safety advice to the public as well as caterers as in some cases the message does not appear to be reaching the intended audiences, for example in relation to cooking advice for livers.

15.3 Ms Liz Redmond responded to Mr Miller’s comments stressing that the FSA did fully consider the kind of evidence contained in paper ACM/1014 in informing the Agency’s risk management programmes and responding to incidents as they arose. In terms of the advice on cooking livers, in addition to the FSA website some broadcasters had been contacted specifically to re-enforce the advice and advice was also re-issued direct to caterers and through the British Hospitality Association. Ms Redmond confirmed such issues were taken very seriously and the FSA would look again to see if there is any more they can do in disseminating these food safety messages.