ACMSF Minutes: 11 March 2008

Meeting held at 10.30am in Aviation House, London, WC2B 6NH.


Professor P Williams

Mr J Bassett
Mrs V Buller
Prof J Coia
Dr R Holliman
Mr A Kyriakides
Ms E Lewis
Mr P McMullin
Dr S Millership
Mrs J Morris

Mr S Wyllie (Defra)
Dr J Hilton (FSA)
Dr S Neill (AfbiNI)

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

Others (members of the public):
Mr Steve Batchford Brakes
Dr Roy Betts Campden & Chorleywood Food Research Association
Ms Fiona Brookes Northern Foods
Ms Bridgette Clarke Bakkavor Ltd
Mr Andrew Curtis Food and Drink Federation
Ms Jane Duddle Waitrose
Ms Kaarin Goodburn Chilled Food Association
Mr Rick Pendrous Food Manufacture magazine
Mrs Ishbel Mackinnon HUSH
Dr Thomas Quigley Food Protection Board, Ireland

1. Chair’s introduction

1.1 The Chair welcomed ACMSF Members and members of the public to the 66th meeting of the Committee. He informed Members that he was chairing the meeting on behalf of Professor O’Brien who was attending the first meeting of the General Advisory Committee on Science. He also welcomed Dr Linden Jack (FSA) who would be presenting agenda item and Dr Rowena Kosmider (VLA) who would be presenting agenda item 8.

1.2 He asked Members to identify any items for discussion under any other business at the end of the meeting. Mr Wyllie wished to raise one item in relation to a recent Commission Working Group on Zoonoses meeting.

2. Apologies for absence

2.1 Apologies for absence were received from Ms Sue Davies, Dr David Brown, Professor Tom Humphrey, Professor Paul Hunter, Professor Mike Gasson, Professor Sarah O’Brien and Mr Robert Rees.

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 item 6, Sainsbury’s sold the food types implicated for discussion under this item.

4. Minutes of the 65th meeting (ACM/MIN/65)

4.1 Members approved ACM/MIN/65 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/890 detailing matters arising from previous meetings. There were no comments raised by Members in response to this paper.

6. Microbiological Safety of ready to eat salads (ACM/891)

6.1 At the Chair’s invitation, Dr Linden Jack (FSA) introduced paper ACM/891. She informed the Committee that since 2001 the Agency had advised consumers to wash ready to eat bagged salads before consumption. This followed an outbreak of Salmonella newport where bagged salad was identified as the source. The FSA had recently reviewed this advice as the industry had introduced further controls to reduce hazards and risks associated with fresh produce; moreover, research had shown that washing could not guarantee the removal of any pathogens that might be present on the product. She explained that the FSA had been unable to find any evidence to suggest that re-washing ready to eat salads by consumers would increase public health protection. Therefore she sought the view of the Committee on the Agency’s recommendation to amend its consumer advice so that it no longer included a recommendation to re-wash ready to eat salads.

6.2 In the ensuing discussion the Committee considered that:

  • Research based on inoculated samples of ready to eat salads had shown that industry controls achieved a 1-2 log reduction in contamination and that there was no evidence to suggest that additional washing by the consumer would provide any additional benefit in reducing contamination further. Responsibility for controls on these products should be placed on industry not the consumer.
  • Outbreak data presented in the paper indicated that outbreaks associated with ready to eat bagged salads were rare, although it was noted that there had been a number of recent occasions where pre-washed salad had been withdrawn from the market due to Salmonella contamination.
  • Clear labelling was needed to allow the consumer to distinguish between ready to eat and ready to wash leafy salads.
  • The presence of a low level of residual pathogens after washing could be a risk factor for vulnerable groups, particularly where a time lapse existed between purchase and consumption. Members acknowledged that although the NHS advised pregnant women to wash salads, this advice was probably linked to risk factors associated with toxoplasma and consumption of home grown salads.
  • With regard to industry controls, bagged salads contained leaves originating from a variety of countries. Members were informed that, for the majority of manufacturers and retailers, overseas products for the UK market met similar standards to those produced in the UK.
  • paragraph 7 of paper ACM/891 should be expanded to provide the evidence for the experimental data.

6.3 The Chair thanked Dr Jack for her presentation. He concluded that ACMSF supported recommendations that the Agency’s consumer advice to wash pre-washed ready to eat bagged salads was no longer appropriate and that the Agency should consider revising this advice to remove the recommendation to wash these products. He also requested that the FSA amend paper ACM/891 to include the experimental detail supporting the quoted research. Lastly, he proposed that the HPA present an update on the microbiological status of ready to eat foods at a future meeting.

Action: FSA and HPA

7. ESBLs (ACM/892)

7.1 At the Chair’s invitation, Dr Holliman introduced paper ACM/892. He informed Members that the Working Group on emerging pathogens had been charged by ACMSF to assess the risk to human health from Extended-Spectrum-beta-lactamase (ESBL) producing E.coli in the food chain. He explained that ESBLs had been of concern in human medicine for some time due to their ability to confer on bacteria the ability to resist a wide range of beta-lactam antibiotics, which resulted in difficulties in treating infections in animals and humans. The Group were asked to consider:

  • Evidence to suggest food was the primary source of ESBL-producing E.coli:
  • Frequency of these organisms in food and humans;
  • Whether human food transmission could be cyclical;
  • Whether E.coli should remain the focus of surveillance for ESBLs; and
  • The validity of a holistic approach.

7.2 Dr Holliman summarised issues considered by the Group. These included routes of transmission via food, person-to-person, animals to humans and by direct contamination. Organisms similar to those identified in human isolates had been identified on a cattle farm in Wales. However molecular studies had shown that organisms identified in these animals were not identical to those found in humans. He also summarised evidence considered by the Group to establish the role that food might play in transmission of ESBL producing E.coli noting a small survey of raw chicken where these organisms had been found. The Group were of the view that cooking would minimise any risk of transmission, and that correct handling was also important in minimising disease via cross contamination. However based on current evidence there was insufficient data available to suggest that food was a significant source of ESBL transmission. There was also insufficient data available to comment on likely cyclical transmission from animals to humans and vice versa. Both the Defra Antimicrobial Resistance Coordination Group and the Antimicrobial Resistance and Healthcare Associated Infection Committee (ARHAI) were considering ESBLs. The Group considered that a cross governmental approach to consideration of ESBLs was required. The Group also concluded that surveillance needed to be undertaken across a variety of sectors and should not be restricted to isolated surveillance of food commodities. A holistic approach was needed to investigate ESBLs and the Group considered that ARHAI were best placed to take forward this issue. There was insufficient evidence to assess the associated risk of ESBL transmission from food to humans and animals.

7.3 Members discussed the role of surveillance to increase understanding of ESBL transmission. Dr Holliman explained that the Working Group considered that parallel structured animal, human and food surveillance was needed to build up a holistic view as molecular transmission data was inadequate at present.

7.4 The Chair thanked Dr Holliman for his report. He confirmed that the Committee endorsed the work of the Working Group and requested that the Working Group keep a watching brief on this issue. Dr Hilton agreed to keep ACMSF up to date with developments at ARHAI.

Action: FSA

8. Presentation on probabilistic risk assessment

8.1 At the Chair’s invitation, Dr Kosmider (VLA) briefed the Committee on approaches to food safety risk assessment. She provided an overview of the quantitative risk assessment process which included application of model pathways, identification and collection of data, data sources and requirements, modelling approaches along the pathway, and probabilistic approaches to assessing risk. Roles of outputs and advantages and disadvantages of probabilistic risk assessment modelling were also summarised.

8.2 Dr Cook (FSA) outlined international approaches to risk assessment. At Codex Enterobacter sakazakii in infant formula had formed the driver for the development of a web-based approach to international risk assessment. EFSA had also considered approaches to EU risk assessment. He reminded Members that the ACMSF’s second report on Salmonella in eggs contained estimates of risk, and indicated that since publication of this report the FSA had developed a probabilistic risk assessment model for Salmonella in eggs. This work would be brought to ACMSF for consideration at a future meeting as the modelling was currently being subjected to peer-review.

8.3 The Chair thanked Dr Kosmider and Dr Cook for their presentation.

9. Epidemiology of Foodborne Infections Group (EFIG)

9.1 At the Chair’s invitation Dr Hilton updated Members on the recent EFIG meeting which took place on 4 March. She reviewed the human data covering the period January to December 2007. She informed Members that Salmonella reports were fairly stable, showing a decrease in 2007 compared to 2006 for Salmonella enteritidis PT4 and Salmonella typhimurium. She summarised reports of different non-PT4 Salmonella enteritidis phage types which were showing increases in 2007 noting that these were geographically specific. HPA were planning to review trends in different phage types of Salmonella enteritidis. An increase in incidence of Salmonella anatum had been reported in Scotland and the North East which was being investigated. There was a reported increase in Campylobacter in 2007 and levels were now higher than those reported in 2001. HPA presented a paper reporting an increased incidence of Campylobacter in the elderly since 2004 with a very sharp increase between 2006 and 2007. A number of possible explanations might account for the increase since 2004, including travel and increased usage of proton pump inhibitors. However, these were unlikely to explain the sharp increase in 2007. A recent paper to the FSA Board outlined progress towards delivering the Agency’s Campylobacter target. Listeria reports indicated a further increase in listeriosis in 2007, with twice the number of reported cases compared to reported data for 1990. Levels of E.coli O157 decreased in 2007, following an increase in 2005/6. Overall VTEC figures had not varied significantly since 2000. In Scotland levels of E.coli O157 were almost three times higher than for the rest of the UK. Work was in progress to examine how VTEC outbreaks were investigated across the UK.

9.2 Reports of cases of Salmonella in animals for 2007 were generally one third lower than in 2006. This may have been due to a decrease in submissions. There was a reported increase in Salmonella in layer flocks and pigs possibly as a result of monitoring changes due to implementation of the Salmonella National Control Plan. A few cases of Salmonella hadar were also reported. A VTEC outbreak associated with two farms was investigated. No E.coli O157 were found in the cattle but 4% of affected cattle had other types of VTEC, mainly VTEC O26. VLA had also investigated Cryptosporidium in pigs as a high rate of shedding of oocysts had been reported. The genotype that was found proved not to be one judged likely to cause human disease.

9.3 The Chair thanked Dr Hilton for her update.

10. Committee sub-groups

Vulnerable Groups

10.1 In the absence of Professor Hunter, Mr Kyriakides informed Members that the Group met on 13 December. He reminded the Committee that the Group had been asked to consider vulnerable groups, organisms and risk factors and to identify appropriate controls and measures. At the request of the Committee, the Group was currently focussing its efforts on listeriosis in the elderly. At the last meeting the Group considered information provided by the HPA including tentative data linking cases to food groups. Due to the preliminary nature of the data it was difficult to draw any firm conclusions. The Group also discussed demographics and consumption patterns in the over 60’s age group including food types consumed, food storage behaviours and consumption patterns in the home. Available data was however limited. The focus of the work is likely to reiterate advice to general public with a focus on the over 60’s age group. The Group had drafted an outline report which it will consider in April with a view to bringing its findings to date to the full Committee in June.

Botulism in cattle, sheep and goats

10.2 Mr Kyriakides informed Members that the Group had not met since the last AMCSF meeting. However it was convening that afternoon to finalise its report. 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 June. 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.

11. Dates of future meetings (ACM/893)

11.1 The Chair brought to Members’ attention paper ACM/893 which listed the dates for 2008 and 2009. He reminded Members that all meetings were open to members of the public.

12. Any other business

12.1 Mr Wyllie updated Members on discussions at a recent Commission Working Group meeting on Zoonoses. Topics under discussion included publication of targets for turkey breeders and a document summarising proposals on Salmonella controls in each sector. He added that Denmark had applied for special guarantee status due to its low prevalence of Salmonella. The Group agreed to produce general guidance notes for Member States who wished to make an application for this status.

13. Public questions and answers

13.1 Ms Kaarin Goodburn (Chilled Food Association) welcomed that the Committee had recognised the good agricultural practice and industry controls in place for ready to eat salads, and asked whether the FSA would give public support for such practices to be required in relation to other fresh produce, including herbs and wholesale salad vegetables. Dr Hilton replied that the FSA would consider this in the light of ACMSF’s recommendations. Mr Kyriakides added that good agricultural practice should apply to all products of this nature.

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