ACMSF Meeting minutes 17 March 2000

Minutes of the 36th ACMSF Meeting, held 17 March 2000, Department of Health, London.


Chairman Professor D L Georgala

Members Mr D Clarke
Dr T Clayton
Mrs P Jefford
Professor A M Johnston
Ms E Lewis
Dr M J Painter
Professor S R Palmer
Dr T A Roberts
Dr N A Simmons
Professor W C S Smith
Mrs B W Thomas
Dr T Wyatt

Assessors Dr M Donaghy (SEHD)
Mr P J R Gayford (MAFF)
Dr R J Harding (MAFF)
Professor C H McMurray (NIDARD)
Dr R Skinner (DH)
Mr D Worthington (NAW)

Secretariat Dr J Hilton (Medical Secretary)
Mr C R Mylchreest (Administrative Secretary)
Mr R Greig
Mrs E Stretton

1. Chairman's introduction

1.1 The Chairman welcomed Members to the Committee's thirty-sixth meeting. He mentioned that this was Mr Greig's last meeting as a member of the Secretariat and thanked him for all the help he had given the ACMSF over the past year.

1.2 He reminded Members of the need to declare any interests in any of the items for discussion. No such declarations were made.

1.3 The Chairman drew attention to the following tabled papers - ACM/459/1, a replacement page for ACM/459, and ACM/460 on animal Salmonella incidents.

1.4 The press release of the Committee's 35th meeting had been issued on 17 December. A number of enquiries had been received by the Secretariat about the MAFF-funded national study on the microbiological quality and heat processing of cows' milk.

2. Apologies for absence

2.1 Apologies for absence were received from two Members, Mr Kilsby and Dr Stevens, and from one Departmental Assessor, Dr Mitchell.

3. Minutes of the 35th meeting

3.1 In relation to paragraph 5.3, Professor McMurray pointed out that the Mycobacterium paratuberculosis (MPTB) pilot study results had not been confirmed by isolation in pure culture. The Secretariat was asked to produce a form of words which reflected the fact that there had been an incremental progression in the available evidence, from the pilot study indication that MPTB might survive pasteurisation, to the confirmation provided by the positive results which were emerging from the on-going 1,000 sample survey.

3.2 The minutes were accepted as a correct record subject to resolution of the MPTB point.
Action : Secretariat

4. Matters arising

4.1 It was reported, in relation to paragraph 11.1 of ACM/MIN/35, that Ministers had now agreed to the publication of the Committee's 1999 Annual Report. It was hoped that publication would take place before the end of April 2000.

4.2 The report of MAFF-funded surveillance of E. coli in unpasteurised milk cheeses on retail sale, which Members commented on in draft (ACM/MIN/33 paragraph 13 and ACM/MIN/35 paragraph 4.4), had now been published. Copies had been sent to Members for information.

5. Trends in salmonellosis

5.1 Dr Robert Adak of the Public Health Laboratory Service provided an oral overview of current trends in salmonellosis. UK data covering faecal isolations from humans were provided in papers ACM/459 and ACM/459/1 for salmonellosis, Salmonella enteritidis and S. enteritidis PT 4. Dr Adak noted the marked fall in Salmonella isolations in Great Britain in the past 2 years. These reductions were believed to be genuine and not simply surveillance artefacts. Where food associations had been able to be made, parallel reductions had been seen in poultry and egg-associated outbreaks. The Great Britain trend had not been reflected in Northern Ireland where salmonellosis, S. enteritidis and S. enteritidis PT 4 isolations had shown significant increases.

5.2 Salmonella typhimurium isolations in Great Britain had also declined but this trend had not been reflected in the data for E. coli O157, Campylobacter, SRSV or Cryptosporidium.

5.3 Enter-net data showed similar trends in human salmonellas in other countries in the European Union, although there were marked differences as between individual countries (eg. significant increases in the data for human salmonellosis, S. enteritidis and S. typhimurium in Belgium).

5.4 A number of factors were suggested as possibly influencing the situation in Northern Ireland, including the Republic of Ireland's prohibition on the importation of vaccinated poultry and eggs from vaccinated flocks, and the opening up of trade with Great Britain. It was also noted that Northern Ireland rates had historically been significantly lower than those in Great Britain and were only now approaching historical GB levels.

5.5 Mr Gayford spoke to paper ACM/460 giving Veterinary Laboratories Agency data on Salmonella incidents in food-producing animals. Of particular note was the significant fall in S. enteritidis notifications in chickens in England and Wales. This was particularly seen in broiler flocks as very few isolates were received from laying flocks. For the fourth year running, the total number of incidents and isolations of Salmonella reported in England and Wales had fallen in respect of cattle and pigs. The reduction for cattle had mostly been due to the decline in the number of reports of S. typhimurium DT104. A decline in the number of reports of S. typhimurium incidents had also been seen in sheep, chickens and turkeys. The total number of Salmonella reports had not decreased. In the case of chickens and turkeys, this was thought to reflect increased monitoring of salmonellas generally and the associated increase in reporting of "other" Salmonella serotypes.

5.6 Overall, the total number of incidents and isolations of Salmonella reported in Scotland had continued to fall for cattle, sheep and pigs. Although the incidence of S. enteritidis in chickens had actually increased in 1998, no S. enteritidis had been isolated from chickens in 1999. However, the total of incidents reported in chickens had risen, reflecting a large increase in the reporting of salmonellas other than S. enteritidis and S. typhimurium.

5.7 Significant among provisional Northern Ireland data was the marked reduction in incidents of S. typhimurium recorded in cattle. Incidents of S. typhimurium recorded in poultry remained low whilst incidents of S. enteritidis recorded in 1999 were considerably lower than in 1998 and previous years.

5.8 Members noted the lack of routine animal surveillance in the UK and the consequent shortage of good denominator data. It was noted that Departments hoped to develop improved arrangements, although it was recognised that there would be an associated resource cost.

5.9 Dr Painter reported on progress by the Working Group on Salmonella in Eggs. The Group had met on 8 occasions and had taken oral evidence from a number of bodies. DH Economics and Operational Research Division were helping with risk assessment work. A key development since the Group began its work was the dramatic fall in Salmonella enteritidis in Great Britain, although it had proved extremely difficult to obtain relevant Salmonella data for eggs. Baroness Hayman, the MAFF Food Safety Minister, had formally requested the Working Group's advice on the effectiveness of the BEIC's Lion Code in preventing Salmonella contamination of eggs. The Working Group had been impressed by the measures taken by BEIC to tackle the problem of Salmonella in eggs. These largely reflected the recommendations of the ACMSF's Report on Salmonella in Eggs. The significant additional element was the requirement that all birds destined for Lion Quality egg-producing flocks should be vaccinated against S. enteritidis. In view of the costs associated with Lion Code compliance, and the pressure on egg producers' margins, the BEIC were pressing for some statement of Working Group support for the Lion Code and for some public recognition that the fall in Salmonella was a direct consequence of the vaccination policy. The difficulty for the Working Group was that there had also been a fall in Salmonella in poultry meat despite the fact that broilers (other than breeding stock) were not vaccinated, and that the broiler breeder vaccination programme had been in place for some time. The Working Group would be reluctant to rely exclusively on industry data, even if these were to become available. Members supported the Working Group's view that what was needed, therefore, was immediate Government-funded surveillance to assess the overall level of contamination and also to compare eggs from different production streams, including a comparison between eggs from vaccinated flocks and eggs from flocks where control measures do not include vaccination. In designing the study, advice should be sought from Members of the Working Group.


6.1 Mr Gayford introduced paper ACM/461 which informed Members of two open meetings arranged for the purpose of coordinating the release to the scientific community, the public and the media of information from research, surveillance and case control studies on VTEC O157 and other foodborne pathogens. The aim of the meetings was to enable results from the various studies to be drawn together, and to be considered and discussed in an open forum. The first of the two meetings would be held in June at the Royal College of Physicians in Edinburgh and would cover VTEC O157 only. The second meeting would be held in London in early December. Date and venue had yet to be fixed.

6.2 In discussion, it was noted that there was growing resistance among clinical laboratories to the recommendation from the ACMSF's VTEC Report that they should routinely examine all diarrhoeal stool specimens for E. coli O157. Their preference was for the testing of bloody stools only. Members noted that a substantial proportion of stools containing O157 VTEC were not bloody and reaffirmed the importance of the Committee's recommendation for the routine testing of all diarrhoeal stools.

6.3 Dr Harding introduced paper ACM/463 prepared by the Microbiological Safety of Food Funders' Group (MSFFG). This was the final version of the draft paper (ACM/457) seen by the Committee at its 35th meeting. In addition to providing funders with an overview of publicly-funded VTEC research, the paper identified gaps in knowledge, some of which might merit the commissioning of future research. The intention was for the paper to be published and placed on the Food Standards Agency (FSA) website.

6.4 Members made a number of comments in discussing the paper. Some of the gaps identified in the paper had been filled by other published research (appropriate references could be provided) and the paper needed to make clear that the gaps did not necessarily reflect unmet research requirements. Much of the research was basic research and little had been done to assess the effectiveness of interventions. A strategy was needed to ensure that effective use was made of research results. It was noted that the MSFFG had no powers to commission or direct research. This was the preserve of funding bodies. However, the FSA would be developing a strategy for reducing food poisoning, and research would be an important component.

6.5 It was noted that the vehicles for VTEC infection appeared to have changed over recent years. Minced meat products like burgers were now featuring less prominently as vehicles for infection. Water, milk and direct contact with animals were being now seen more frequently. A view was needed of the relative importance of the various exposure pathways and the required protective measures. However, it was also extremely important to keep in mind that VTEC infection could occur at any time that food was mishandled.

7. Future work programme

7.1 The Chairman reminded Members that the Committee had held a preliminary discussion at its 35th meeting and had agreed to set up an Ad Hoc Group to help elaborate the future work programme with greater precision. The Group, had met on 6 March 2000. Paper ACM/465 summarised the Group's work and recommendations. The areas for possible future work identified by the Group had been risk control, Campylobacter, ready-to-eat fruit and vegetables, and Listeria.

7.2 Members agreed that an Ad Hoc Group should be convened to review why risk control was not being universally applied amongst small and medium size enterprises in manufacturing and catering, and in the domestic environment. In relation to domestic practices, Members considered that, although consumers had an important contribution to make in protecting themselves from the risk of food poisoning, this should not detract from the parallel aim of getting pathogens out of primary production. Members felt that consideration should be given to the inter-relationship between advice to food producers and the general public on risk control, and the contribution of enforcement to the production of safe food. It was agreed that, as part of this preliminary scoping exercise, the Ad Hoc Group should consider the need for a formal Working Group to be set up to take matters forward and formulate appropriate terms of reference for such a Group.
Action : Secretariat

7.3 Members were reminded of the intention to provide the Committee with an MSFFG paper on UK publicly-funded Campylobacter research. This was to be followed by a workshop which would be designed to engage the ACMSF in a stock-take of progress on research thereby helping identify where changes of direction and fresh initiatives might be required. Members supported the Ad Hoc Group's recommendation that a formal Working Group should be constituted to take stock of the research paper and the outcome of the planned workshop, consider the results of other (national and international) research, and identify possible steps for building a strategy to reduce the incidence of Campylobacter infections in humans. Action : Secretariat

7.4 Members agreed with the Ad Hoc Group's recommendation that, to enable a view to be taken of the potential risks associated with ready-to-eat fruit and vegetables and the need for further work by the Committee, the PHLS should be asked to provide a briefing paper. This should give an up-to-date view of the microbiological status of ready-to-eat fresh fruit and vegetables, including the international dimension.
Action : Secretariat

7.5 Members also accepted the recommendation of the Ad Hoc Group in relation to Listeria that Department of Health (DH)/PHLS should be asked to produce a briefing paper on the French outbreak which had occurred over Christmas 1999/New Year 2000. This would help the ACMSF to take a view on whether the errors made which led to that outbreak and the one in 1998/99 in the USA, were sufficiently well rehearsed and understood, or whether these two outbreaks raised new issues which the Committee needed to address.
Action : Secretariat

7.6 Members noted that the Ad Hoc Group had reviewed the outcome of the DH study seminar and workshop on infectious intestinal disease and had pointed to the need to take stock of whether surveillance data on human foodborne disease contributed to the development of effective public health protection strategies. In this connection, Members also stressed the need to integrate human and animal data. It was agreed that, as a first step in addressing this issue, contact should be established with the Epidemiology of Foodborne Infections Group who were planning to take a more fundamental look at surveillance.
Action : Secretariat

7.7 It was agreed that Mycobacterium paratuberculosis (MPTB) was a topic which the ACMSF would need to return to in the future. MAFF had in place a detailed programme of research and surveillance to detect MPTB in milk and to investigate the effect that pasteurisation had on the organism's survival. The Committee had provided advice on the results of this work as and when it had become available. In addition, the Advisory Committee on Dangerous Pathogens had reviewed the evidence for and against the link between MPTB and Crohn's disease but had concluded that the case for MPTB as the aetiological agent of Crohn's disease could neither be proved nor disproved on current evidence. The Chief Medical Officer had advised that, on the basis of what was currently known about MPTB, there was no need to change dietary habits.

7.8 The Joint Food Safety and Standards Group was currently engaged in a year-long, nation-wide survey to investigate the microbiological quality of raw and pasteurised cows' milk. One third of the samples were being examined for the presence of MPTB. The Committee had received early results in December 1999 (ACM/458). Viable MPTB had been found in 4 of 129 pasteurised milk samples. Members acknowledged at that time that the relevance of the organism to human illness was unknown but expressed some concern that it had been detected in pasteurised milk. They had agreed that it was important to establish whether MPTB had survived pasteurisation or whether there was some other explanation for the positive results. Further scientific work was needed to help establish the conditions under which MPTB could be eliminated from milk. Work was also being funded by MAFF on Johne's disease control strategies in other countries. The Committee agreed that it should re-examine the position as soon as results from on-going work became available.

8. Oral reports

8.1 The Committee received a number of oral reports.

8.2 Dr Hilton reported on the DH IID seminar and workshop. The aim had been to make the results of the IID study available to a wider audience, including participant general practitioners. There was also discussion of how best to take the work forward, including implications for better surveillance and clinical management, and the future use of archived samples. A record of proceedings of the seminar and workshop was being prepared. Publication of the full report of the IID study was expected towards the end of May 2000.

8.3 A summary of Dr Painter's report on progress by the Working Group on Salmonella in Eggs is at paragraph 5.9.

8.4 Mr Mylchreest reported that the Microbiological Food Surveillance Group had held a routine six monthly meeting on 8 March and had been up-dated by funders on current progress in relation to their microbiological food surveillance projects. Mr Worthington reported that the Welsh Food Microbiological Forum had assembled a wealth of data from the All-Wales Sampling Programme. If Members would find it useful, an appropriate presentation could be made to the ACMSF. It was agreed that this offer should be borne in mind for a future meeting.
Action : Secretariat

8.5 Dr Harding reported that the primary school teaching resource, which had been developed as part of the UK Food Hygiene Initiative in Schools, had been launched by Baroness Hayman on 8 March. The contract with the European Commission, under which the Health Education Authority (HEA) had developed secondary and primary schools packs and distributed them free to all UK secondary and primary schools respectively, had now been completed. The HEA would be replaced from 1 April 2000 by the Health Development Agency, which would have no remit to undertake health promotion work and campaigns. The FSA would therefore assume ownership of the two teaching resources for care and maintenance purposes and would be seeking future development funding.

8.6 Dr Skinner confirmed that the 36th meeting would be the Committee's last under existing arrangements. From 1 April 2000, the ACMSF would advise the FSA rather than UK Agriculture and Health Ministers. Ministers would shortly issue a formal direction to give effect to these altered arrangements.

8.7 Mr Greig reported that the Government's response to the Microbial Antibiotic Resistance Report, which was being coordinated by the Veterinary Medicines Directorate, had now been cleared by Ministers and would be published shortly. Copies of the response document would be sent to Members as soon as they became available.

9. Any other business

9.1 Attention was drawn to paper ACM/466 which reported that viruses closely related to Norwalk-like viruses had recently been found in animal stools, sparking discussion about the potential for zoonotic transmission. Conventional wisdom had hitherto been that foodborne viruses which caused human disease were not usually zoonotic and humans were the only source of infection. This was a topic which the Committee might wish to revisit once any detailed assessments of the research reported in ACM/466 had been carried out.

10. Dates of future meetings

10.1 The dates of future meetings in 2000 were confirmed as follows:

21 June
19 September
5 December