ACMSF Minutes: 6 December 2007

Meeting held at Trinity House, Tower Hill, London EC1


Professor S O’Brien

Dr D Brown
Mrs V Buller
Prof J Coia
Ms S Davies
Prof M Gasson
Dr R Holliman
Prof T Humphrey
Mr A Kyriakides
Ms E Lewis
Mr P McMullin
Dr S Millership
Mrs J Morris
Mr R Rees
Prof P Williams

Ms L Larkin (Defra)
Dr J Hilton (FSA)

Dr L Foster (Administrative Secretary)
Dr P Cook (Scientific Secretary)
Mr A Adeoye
Miss S Butler

Dr Roy Betts, Campden and Chorleywood Food Research Association
Ms Estelle Brennan, Lyons Seafoods Ltd
Ms Fiona Brookes, Northern Foods
Mr John Brown, National Consumer Federation
Ms Bridgette Clarke, Bakkavor
Ms Amanda Cryer, British Egg Information Service
Ms Kirsty Dinsdale, ADAS
Ms Jane Duddle, Waitrose
Ms Barbara Gallani, British Retail Consortium
Ms Kaarin Goodburn, Chilled Food Association
Dr Samantha Kirk, Tesco
Mr Alan Long, VEGA
Dr Barbara Lund, Institute of Food Science & Technology
Dr David McCleery, Safefood
Ms Carole Owen, Brakes
Dr Andrea Patterson, Defra
Ms Ceridwen Roberts, FSA Programme Adviser
Dr Bernard Rowe, Consultant, Tesco
Ms Veronica Wright, Meat & Livestock Commission

1. Chair’s introduction
1.1 The Chair welcomed ACMSF Members and members of the public to the 65th meeting of the Committee. She also welcomed Dr Jim McLauchlin and Mr Iain Gillespie (HPA) who would be presenting agenda item 6, Dr Chun-Han Chan (FSA) who would be presenting agenda item 7 and Dr Kathryn Callaghan (FSA) who would be presenting agenda item 8.

1.2 She asked Members to identify any items for discussion under any other business at the end of the meeting. Mrs Morris wished to raise one item in relation to raw milk and the Chair wished to raise several items.

2. Apologies for absence
2.1 Apologies for absence were received from Mr John Bassett, Professor Paul Hunter, Dr Sydney Neill and Mr Stephen Wyllie.

3. 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 Kyriakides informed Members that, in relation to agenda items 6, 7 and 8 Sainsburys sold the food types implicated for discussion under these agenda items. Mr McMullin informed Members that, in relation to agenda item 10 he worked for Poultry Health Services, and also in relation to agenda item 7 he acts as a consultant to the British Egg Industry Council. Professor Humphrey informed Members that, in relation to agenda item 7, he provided advice to the British Egg Industry Council. He also received funding from this organisation.

4. Minutes of the 64th meeting (ACM/MIN/64)
4.1 Members approved ACM/MIN/64 as a correct record of the previous meeting. The Secretariat was asked to arrange for final minutes to be posted on the Committee’s website.
Action: Secretariat

5. Matters arising
5.1 The Chair drew attention to the Secretariat information paper ACM/878 detailing matters arising from previous meetings. There were no comments raised by Members in response to this paper.

6. Listeria update (ACM/879)
6.1 At the Chair’s invitation, Dr Jim McLauchlin and Mr Iain Gillepsie (HPA) introduced paper ACM/879. Dr McLauchlin reminded Members that the Committee was informed of the increase in human listeriosis in England and Wales in September 2005 and that ACMSF received updates in June and December 2006 and June 2007. He reported that the incidence of listeriosis had doubled since 2001 and had occurred in older patients as bacteraemia, in the absence of central nervous system infection. He confirmed that this increase had continued into 2007. Similar increases had also been reported in other European countries. Following the introduction of a standard structured surveillance questionnaire for listeriosis in 2005, sufficient data have now been accrued for preliminary analysis. Initial investigations showed significant differences in the exposure histories of patients infected with different subtypes of Listeria monocytogenes. Separate analysis of data from routine reference typing of isolates from food indicated associations with the same or similar food types. From these findings it was hypothesised that specific food types gave rise to infection with specific Listeria monocytogenes sub types.

6.2 At the Chair’s invitation, Mr Gillespie outlined the strengths and weaknesses of case/case analysis. He explained that, for the data-set under discussion, it was not possible to compare the exposure of individuals with a well-defined control group. He also summarised some of the limitations of the risk analysis, noting that the data represented analyses of the initial data only.

6.3 The Chair informed Members that HPA had also produced a detailed document which supported the information presented in paper ACM/879. This document would be made available for discussion at the ACMSF ad hoc group on Vulnerable Groups meeting which was due to take place on 13 December. She requested that the document was also circulated to all ACMSF Members.
Action: Secretariat

6.4 In the ensuing discussion the Committee considered that:

  • The food data may have been subjected to biases due to the nature of the sampling involved. HPA confirmed that samples were collected from FTE Laboratories. However the food and clinical data sets were independent;
  • It was possible to draw some conclusions from the data presented by HPA. There were multiple strains of L. monocytogenes associated with the increased incidence of listeriosis on the over 60 age group. However no specific strain had been linked to the upsurge in cases. Members agreed that there was a sector of the population that was vulnerable to L. monocytogenes and suggested strengthening the existing advice for avoiding listeriosis to focus on the over 60 age group. However Members also noted that this age group was also vulnerable to serious underlying medical conditions and taking medication which made it difficult to produce advice for the general population in this age group;
  • The at-risk foods associated with the incidence of listeriosis highlighted in the paper were not unusual. Members queried whether repeated exposure to much lower levels of L. monocytogenes was a factor, noting the infrequent occurrence of high levels of Listeria species in a current FSA survey of smoked fish;
  • The increase in listeriosis was not artefactual. Members noted that the observed change in quality of blood culture media had not resulted in increased ascertainment as no extra cultures were taken in the over 60 age group. However it was noted that care of the elderly in hospitals had changed as all patients were being treated equally, irrespective of age;
  • Data on food habits and behaviour were not always reliable as patients always tended to report that they followed correct food hygiene and food storage practices;
  • More information was needed on the areas of greatest risk from contamination of Listeria species in the food chain to inform advice on interventions and control measures;
  • Rates of food spoilage were slower due to improved hygiene and controls resulting in food being kept for longer prior to consumption.

6.5 The Chair thanked Dr McLauchlin and Iain Gillespie for their presentation and the additional papers, which had been produced to support the development of ACMSF advice on listeriosis for the Food Standards Agency. She requested that the ad hoc Group on Vulnerable Groups consider in detail the data provided by HPA including the influence of any potential biases. She also requested that the Group examine other analytical approaches which could address the issues raised.
Action: Ad Hoc group on Vulnerable Groups

7. Egg surveillance (ACM/880)
7.1 At the Chair’s invitation, Dr Chun-Han Chan (FSA) introduced paper ACM/880. She reviewed the work of the ACMSF Salmonella in eggs Working Groups since 1991. She also summarised the background to commissioning of three FSA egg surveys to measure the prevalence of Salmonella in eggs available to the consumer following publication of the Second ACMSF Salmonella in Eggs Report in 2001.

7.2 Dr Chan provided an overview of Salmonella prevalence reported in the FSA surveys and outlined the findings of each survey. She also summarised the Agency’s current advice on eggs to caterers and consumers and EU controls to reduce Salmonella in layer flocks.

7.3 The Chair of the Working Group on Surveillance briefly reviewed the Group’s deliberations on the survey results. He highlighted that, in view of the low prevalence of Salmonella reported in the surveys, the current FSA egg advice was now rather strongly worded. He also highlighted the positive initiatives undertaken by the egg industry to reduce the prevalence of Salmonella.

7.4 Members discussed the FSA advice on eggs in relation to risk communication to the consumer. The Committee agreed that the practical advice should remain the same although the tone of the communication should be revisited in light of the survey results which indicated a low prevalence of Salmonella in eggs available to caterers and consumers. Members noted that despite the lower prevalence, the large number of eggs consumed on a daily basis still offered significant opportunities for public exposure to Salmonella. Members suggested that the advice should include information on the different risks associated with eggs from vaccinated and unvaccinated flocks, egg shell and contents and storage of pooled and shell eggs. Risks of eggs becoming cross-contaminated during handling should also be emphasised. A suggestion was also made to link the advice to information in the FSA’s Safer Food Better Business guidance.

7.5 The Chair thanked Dr Chun-Han Chan for her presentation and requested that the FSA consider revising its advice on eggs to reflect the risks posed by vaccinated and unvaccinated eggs and cross contamination during storage and handling of shell and pooled eggs.
Action: FSA

8. Guidance on vacuum-packaged foods (ACM/881)
8.1 At the Chair’s invitation, Dr Callaghan introduced paper ACM/881. She provided a historical overview of the development of guidance on the safety and shelf-life of vacuum and modified atmosphere packed chilled foods, with respect to Clostridium botulinum. She reminded Members that in June 2006 ACMSF considered the findings of an independent review of Clostridium botulinum, which was previously requested by the Committee to support its deliberations on guidance for chilled vacuum packaged and modified atmosphere packed foods. At this meeting ACMSF recommended the 10 day shelf-life rule for vacuum-packaged and modified atmosphere packaged foods. The Committee also recommended that the FSA set up a small drafting group to revise the guidance to address issues arising from the public consultation on the Guidance on vacuum-packaged foods. Dr Callaghan outlined the scope of the drafting group and explained that the resulting guidance produced by the group was circulated to industry stakeholder for comment prior to being finalised.

8.1 The Committee discussed the scope of guidance. Members recognised that it was difficult to balance simple and complex issues in a single guidance document. They welcomed the fact that the guidance had been developed to assist EHOs carry out their enforcement duties. Members noted that the wording in the Guidance reflected that published in the 1992 ACMSF Report on vacuum packaging and associated processes and that the drafting group, where possible, had avoided overcomplicating messages. The group had also decided not to include specific examples in the text in order to provide some flexibility with regard to enforcement risk management decisions.

8.2 The Chair thanked Dr Callaghan for presenting the guidance and confirmed that ACMSF endorsed publication of the document in early 2008.

9. Codex Food Hygiene meeting (ACM/882)
9.1 At the Chair’s invitation, Dr Paul Cook presented paper ACM/882. He summarised the main outcomes of the 39th session of the Codex Committee on Food Hygiene (CCFH) held in New Delhi, India, 30 October-4 November 2007. The Committee had a very productive session and agreed to advance three documents to the Codex Alimentarius Commission for adoption. These were a proposed draft Code of Hygienic Practice for Powdered Formulae for Infants and Young Children apart from Annex II (Enterobacter sakazakii criterion - which was held for consideration next year), proposed draft Guidelines for the Validation of Food Safety Control Measures and proposed draft Annex II on the Guidance on Microbiological Risk Management Metrics to the Principles and Guidance for the Conduct of Microbiological Risk Management. Ongoing work included the draft Microbiological Criteria for Listeria monocytogenes in Ready to Eat Food and revisions to the scope of the proposed Draft Guidelines for the Control of Campylobacter and Salmonella spp. in Broiler chicken meat to include all chicken meat of the species Gallus gallus and not just young bird meat. ACMSF Members noted that the UK was part of the drafting group on Listeria.

9.2 The Committee did not reach a consensus regarding removal of current international trade restrictions on milk subjected to treatment using lactoperoxidase. New work included development of a commodity specific annex on leafy green vegetables, including leafy green herbs to add to the Code of Hygienic Practice for Fresh Fruit and Vegetables. Development of a Code of Hygienic Practice for Vibrio species in Seafood was also proposed. New work on Foodborne Viruses would be considered at next year’s session. The Committee would also be developing its own risk analysis principles document as requested by the CAC in the context of the Strategic Plan.

9.3 The Chair thanked Dr Cook for his presentation.

10. Update on Avian Influenza
10.1 At the Chair’s invitation, Dr Judith Hilton updated Members on the recent outbreak of Avian Influenza in Suffolk. On 13 November H5N1 virus was confirmed in an organic turkey flock in Suffolk. Dead birds were identified in three of out five sheds, with the majority of deaths being located in the first shed. All the birds in the sheds (including ducks and geese) were destroyed, including 90,000 turkeys. All flocks on the affected sites were tested. One duck tested positive. The organic farm was linked to another company and the farm workers were known to work on another farm. On 26 November a preliminary epidemiological report was published by Defra. This report confirmed the H5N1 strain was of Asian lineage and most closely resembled and isolate seen in the Czech Republic (99.8% homology). There was no evidence that the strain was introduced on to the farm via people, vehicles or food. However transmission via wild birds could not be ruled out. Testing of dead wild birds and bird droppings had not detected the presence of any virus. In terms of risk management action, the FSA placed advice on avian influenza on the front page of its web site. Some flocks were depopulated and it was agreed that, following vet inspection, animals could be moved from the surveillance zone to slaughter and permitted to enter the food chain.

10.2 Members considered that there was no new scientific evidence to warrant a review of the ACMSF’s risk assessment on Avian Influenza.

10.3 The Chair thanked Dr Hilton for her update. She noted that the recent outbreak had not highlighted any new scientific information for consideration. Therefore it was not necessary to reconvene the Working Group on Avian Influenza. However she requested that the Working Group maintained a watching brief on developments.

11. Epidemiology of Foodborne Infections Group (EFIG)
11.1 At the Chair’s invitation Dr Hilton updated Members on the recent EFIG meeting which took place on 30 October. She reviewed animal data for the first six months of 2007 noting that there was little to report. She highlighted that an early detection system had been instituted by VLA to detect signs of increased reporting for individual serotypes. She also reviewed the human data covering the period January to September 2007. She reported that Salmonella reports continued to show a levelling of with little change in incidence since 2005. However Campylobacter reports increased in 2007 after four years of stability. Listeria reporting rates have risen and were currently at a similar level to the peak seen in 2003. VTEC O157 rates have returned to 2003 levels although high rates were continuing in Scotland. Trends were similar across GB. Rates of Campylobacter and Listeria had continued to decrease in Northern Ireland. The number of outbreaks had continued to decrease. Other areas considered by EFIG included an update on sorbitol-fermenting E.coli O157, further data from a Campylobacter case control study, CHRO conference, non-PT4 Salmonella Enteritidis foreign travel cases, antimicrobial usage, food surveys, National Control Plans for Salmonella in breeding and laying flocks, updates on EU layer and broiler surveys, HPA review of surveillance systems and a foodborne disease strategy review workshop.

11.2 The Chair thanked Dr Hilton for her update.

12. Committee sub-groups

Newly emerging pathogens
12.1 In the absence of Professor Hunter the Chair reported that the second meeting of this Group had taken place in November to discuss ESBLs. The Group considered information relating to ESBLs on a farm in Wales provided by VLA, EU research on ESBLs and received an update from the Defra Antimicrobial Resistance Coordination Group. The Group was also briefed on the new overarching Advisory Committee on Antimicrobial Resistance and Healthcare Associated Infection and its sub-groups. The Group concluded its consideration of the evidence and will report the outcome of its deliberations to ACMSF in March 2008. Key conclusions arising from the Group were that a holistic approach was required to the consideration of ESBLs; based on current evidence there was no epidemiological evidence to support the view that food was a major risk factor for ESBLs; and that the Group should keep a watching brief on developments.

Vulnerable Groups
12.2 In the absence of Professor Hunter, Mr Kyriakides informed Members that the Group has not met since the last ACMSF meeting. The next meeting of the Group would take place on 13 December. At this meeting the Group would consider the L. monocytogenes data presented by HPA and food consumption data for the over 60s age group. A further update would be provided at the March meeting.

Botulism in cattle, sheep and goats
12.3 Professor Williams informed Members that the Group met on 18 October. At this meeting the Group considered animal husbandry practices for sheep and goats and risk factors for milk and meat production with respect to Clostridium botulinum. He confirmed that there was no information available on botulism in buffalo so this species was excluded from consideration. John Bassett was co-opted onto the group to provide advice on risk. In summary the Group concluded that the recommendations to lift restrictions applied to cattle should also apply to movement of meat and milk from sheep and goats. A report on the Group’s deliberations would be provided to the ACMSF in March 2008. It was likely that the report would form an addendum to the existing botulism in cattle report, and that the addendum would be subjected to public consultation.

13. Dates of future meetings (ACM/884)
13.1 The Chair brought to Members’ attention paper ACM/884 which listed the dates for 2008. She reminded Members that all meetings were open to members of the public.

14. Any other business
14.1 Mrs Morris informed Members of recent media coverage promoting the nutritional benefits of raw milk, which advocated that raw milk was fed to children. Members expressed concern that the microbiological risks associated with consumption of raw milk needed to be highlighted and suggested that the FSA reiterate its advice on consumption of raw milk.

14.2 The Chair confirmed that the ACMSF position on consumption of raw milk had not changed. ACMSF continued to advise that raw milk should not be made available for public sale. Dr Hilton added the FSA’s Chief Scientist had pointed out the risks from consumption of raw milk on his website blog.

14.3 The Chair informed Members that in the summer she met with Pat Troop (CE, HPA) and Professor Bill Reilly (FSA Board Member) to discuss gastrointestinal surveillance. At this meeting she reiterated the importance of high quality surveillance data to support the work of ACMSF. It was agreed that she would meet with Professor Peter Borriello (HPA) twice a year to keep the issue on the agenda. In October she attended the annual dinner for Scientific Advisory Committee Chairs. Issues discussed included the formation by the Agency of the over-arching General Advisory Committee on Science and an Advisory Committee on Social Sciences. Other meetings she had recently attended on behalf of ACMSF included a workshop to review the Foodborne Disease Strategy, an Antibiotic Resistance stakeholder workshop, and the cross-departmental National Expert Panel on New and Emerging Infections.

Public Questions and answers

14.1 Dr Bernard Rowe (Consultant to Tesco) raised two issues in relation to L. monocytogenes relating to access to the hospital notes of elderly patients and the low number of AFLP profiles. The Chair confirmed that the ACMSF Vulnerable Groups sub-group would probably consider case notes information as part of its deliberations.

14.2 Dr Barbara Lund (IFST) commented on the prevalence of Listeria species in vacuum-packed foods at the end of shelf life. She referred to a recently published paper in the Journal of Food Protection which reported that at the end of shelf life 1 sample in approximately 3000 packs of cooked meats contain >1000,000 L. monocytogenes/g. She noted that the Guidance on these foods discussed in the meeting only focussed on Clostridium botulinum.

14.3 Mr Alan Long (VEGA Research Trust) commented on several issues relating to movement of livestock, terrorism, bovine tuberculosis and imported foods. The Chair commented that issues relating to the international movement of people and food were the responsibility of several Government Departments including FSA and HPA. She added the ACMSF ad hoc Group on Imported Foods examined the microbiological risks associated with imported foods of animal and non animal origin.

14.4 Mr David McCleery (Safe Food) informed the Committee that an increase in pregnancy associated cases of listeriosis linked to non-Irish born citizens had been reported in the island of Ireland and that work was in progress to promote advice on listeria to different ethnic groups. He also informed Members that a recently funded shell egg survey had shown a lower prevalence of Salmonella compared to 2003 data. There was no difference in the reported prevalence in eggs from Northern Ireland or the Republic of Ireland, despite vaccination not being carried out in the Republic of Ireland. The report of this survey would be published in early 2008.

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