ACMSF minutes: 5 December 2006

Meeting held at Trinity House, Tower Hill, London EC1

Acting Chair:
Professor S O'Brien

Mr J Bassett
Dr D Brown
Mrs V Buller
Prof. M Gasson
Mr A Kyriakides
Ms E Lewis
Mr P McMullin
Dr S Millership
Mrs J Morris
Prof. L Piddock
Mr R Rees

Assessors :
Mr P Gayford (Defra)
Dr J Hilton (FSA)

Secretariat :
Dr L Foster (Administrative Secretary)
Mr Ade Adeoye
Miss Sarah Butler

Members of the public:
Mr Derek Armstrong, Meat and Livesstock Commission
Ms Fiona Brookes, Chilled Food Association
Dr Chun-Han Chan, FSA
Ms Bridgette Clarke, Bakkavor
Dr Charmaine Clarke, Food Safety Promotion Board, Ireland
Mr Andrew Curtis, Food and Drink Federation
Dr Michael Farrelly, University of Liverpool
Dr Linden Jack, FSA
Miss Lesley Larkin, Defra
Mr Alan Long, VEGA
Dr Barbara Lund, Visiting Scientist, IFR
Ms Gael O'Neil, FSA
Mr Milorad Radakovic, FSA
Mr Rick Pendrous, Food Manufacture magazine
Dr Sophie Rollinson, FSA
Mr Bernard Rowe
Mrs Jackie Spencer, FSA

Chair's introduction
1.1 The Chair welcomed ACMSF Members and members of the public to the 61st meeting of the Committee. She also welcomed Mr Iain Gillespie (HPA) who would be presenting agenda item 6, Dr Joanne Aish (FSA) who would be presenting agenda item 8, and Mrs Joanna Fullick (FSA) who would be presenting agenda item 9.

1.2 The Chair asked Members to identify any items for discussion under any other business at the end of the meeting. Professor Piddock indicated that she wished to raise an item relating to the FSA�s postgraduate scholarship scheme. The Chair informed Members that she would briefly update them on re-appointments to the Committee and her attendance at a recent dinner for Advisory Committee Chairs. She added that the Secretariat also wished to update members on the ACMSF Chair appointment.

Apologies for absence
2.1 Apologies for absence were received from Dr Paul Cook, Ms Sue Davies, Professor Tom Humphrey, Dr Rick Holliman, Professor Paul Hunter, Ms Eva Lewis, Mr Sydney Neill and Professor Peter Williams.

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. None were declared.

Minutes of the 60th meeting and matters arising
4.1 Members approved ACM/MIN/60 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

Matters arising

5.1 The Chair drew attention to the Secretariat information paper ACM/813 detailing matters arising from previous meetings. Professor Piddock sought clarification on whether antimicrobial resistance would be considered as part of the Committee�s horizon scanning activities as she was not present at the last meeting when discussion of this issue took place. Dr Foster explained that antibiotic resistance was not identified as one of the key priorities for discussion by the Committee in the current round of activity. She added that the Committee had agreed to focus its attentions on a range of issues linked to vulnerable groups.

Listeria update
6.1 At the Chair's invitation, Mr Iain Gillespie (HPA) introduced paper ACM/814. He reminded Members that in December 2005 the Committee was informed of a change in the epidemiology of Listeria monocytogenes infection in England and Wales. Notably, an increased incidence since 2000 which could not be explained by outbreaks recognised during this time. In June the Committee was informed that the incidence in England and Wales remained higher than pre-2001 levels. An increased incidence of listeriosis was also reported in Scotland, with presentation similar to that reported in England and Wales. Additional data confirmed that the increase was not artefactual. The disease occurred predominantly in older patients with bacteraemia in the absence of CNS infection. No increase was observed in Northern Ireland.

6.2 He added that data from the first six months of 2006 indicated that illness in older patients with bacteria still predominated. However it was stressed that it was difficult to draw conclusions from this data due to reporting delays associated with passive surveillance. Lastly, Mr Gillespie outlined work in progress and resources required to investigate the changing epidemiology of listeriosis.

6.3 In the ensuing discussion the Committee:

  • considered that case control studies were of limited use in investigating the epidemiology of listeriosis as patients were often too ill to be interviewed;
  • reiterated concerns linked to adequate and flexible resourcing of epidemiological investigations carried out by HPA. Members noted that no significant progress had been made to establish the reason for the increase in incidence in listeriosis over the 12 month period since the change in epidemiology was first brought to the attention of the Committee. Members also highlighted the need for a UK wide approach to investigation of listeriosis involving HPA Centre For Infections and HPA regional units. The FSA assessor acknowledged concern about resources at HPA and informed the Committee that the FSA Board were being made aware of the ACMSF's concerns and that this was being pursued with DH Ministers;
  • reiterated the need for a three pronged investigative approach to identify changes in the pathogen, assess the vulnerability of the target group and identify vehicles of exposure;
  • suggested that typing, whole genome analysis and examination of molecular isolates might provide more information about the functionality of the organism and the observed change in epidemiology;
  • agreed to revisit listeriosis in the UK in June 2007

Toxoplasmosis and food
7.1 At the Chair's invitation, Dr Judith Hilton (FSA) presented paper ACM/815. She informed Members that recent research carried out in the US and the Netherlands had indicated that the disease burden due to toxoplasmosis might be more significant than previously thought. She explained that policy in the UK had tended to focus on risks to pregnant women associated with cat faeces and not foodborne risks. Therefore she sought the views of the Committee on the significance of the disease and foodborne risks in the UK, and whether further investigation and surveillance was warranted to obtain robust data on UK prevalence and foodborne sources of toxoplasmosis.

7.2 Members considered that enhanced surveillance for toxoplasmosis would not have a major impact due to under-recognition. However it was difficult to draw any firm conclusions due to the limited amount of data available. Consideration would need to be given to information on exposure from non food sources in order to assess relative exposure from a food perspective. Examination of sero-prevalence data from the US and the Netherlands and serology to identify IgM responses might also be warranted.

7.3 The Chair thanked Dr Hilton for her update. She requested the HPA to present a more comprehensive overview of human toxoplasmosis in UK, US and the Netherlands at the next meeting.
Action: Secretariat

Botulism in cattle
8.1 At the Chair's invitation Dr Joanne Aish introduced paper ACM/816. She reminded Members that at the September meeting the Committee approved the finalised botulism in cattle report (following public consultation) for submission to the FSA Chair for publication and printing. Paper ACM/816 updated Members on action taken by the Agency to implement the recommendations in the report. Dr Aish outlined the current voluntary restrictions in place for movement of meat or milk from healthy cattle for farms where there had been suspected cases of botulism. She also summarised the key conclusions and recommendations in the report arising from the work of the Ad hoc Group on botulism in cattle. She explained that, in line with the recommendations in the report, the Agency would be implementing a change to its advice and would no longer request voluntary restrictions for healthy cattle from farms where cases of botulism were suspected. However this would need to be reviewed if new evidence emerged that the botulism toxin types that affected humans were causing outbreaks in cattle. The Agency would still be informed of cases of suspected botulism in cattle as there might be additional issues for consideration to ensure protection of the food chain. Stakeholders would be informed of the change in the Agency's advice later in the month. Lastly, Dr Aish informed Members that the Agency shortly intended to seek the ACMSF's advice on the potential risk to human health from food chain issues linked to botulism or suspected botulism in sheep and goats.

8.2 The Committee supported the Agency's approach to implementing the ACMSF's recommendations. Mr Gayford added that Defra also welcomed the Committee's report and that Defra would be following up the recommendations and that comments would be published on Defra's web site. He explained that samples being taken and sent for examination had only isolated toxin type D. Toxin types A, B, C and E had not been identified. A sample storage system was also currently being set up to support development and validation of new in vitro tests.

8.3 The Chair thanked Dr Aish for her presentation. She confirmed that the Committee supported the Agency's implementation of ACMSF recommendations on botulism in cattle.

Disinfection of knives
9.1 At the Chair's invitation Mrs Fullick (FSA) presented paper ACM/817. She explained that under the new EU Food Hygiene Regulations abattoirs were required to have facilities for disinfecting tools with hot water supplied at not less than 82
C, or an alternative system having an equivalent effect. She outlined the EU's Scientific Committee's opinion and work to develop alternative methods carried out in Australia. Lastly she sought the views of the Committee on whether:

  • a performance standard for knife sterilisation of a 3 log reduction in E.coli was appropriate provided that visible contamination was removed prior to immersion;
  • a generic 'approval' was an acceptable approach; and
  • what further industry data was required to support alternative time/temperature and hygiene parameters in place of water at 82

9.2 Members considered that, with regard to the proposed 3 log reduction, it was important to consider the impact of washing knives on the end product. Members also queried the effectiveness of current sterilisation practices and the impact of effective application of time and temperature parameters on knives when used on a mechanical line. The Committee discussed application of z values to develop time/temperatures equivalent to 82
C [for 1 second], preferring application of a theoretical heat equivalent process. Members suggested that application of modelling work developed by the Committee to assess the safe cooking of burgers could assist calculation of lower time/temperature combinations capable of delivering equivalent lethality to that at 82
C. More information was also needed on the current microbiological load on knives in order to assess the validity of the proposed 3 log reduction. The Committee was opposed to the use of chemical disinfection. Some Members expressed concern over the proposed adoption of a generic approach as each area in the slaughter house presented different challenges.

9.3 Mrs Fullick confirmed that microcriteria had now been set for raw meat for process control in slaughterhouses and agreed that the use of chemical disinfectants was unlikely to be appropriate in the slaughterhouse setting. She added that the Agency would consider alternative approaches to knife sterilisation on a case by case basis taking account of the operator's HACCP-based approach in each slaughterhouse.

9.4 Summing up, the Chair noted that whilst 82
C was highlighted as the preferred standard for disinfection of knives, more information was required to assess what this delivered in terms of microbiological safety. E.coli modelling work by the ACMSF to assess safe processing controls for cooking of burgers could be applied to develop time/temperature equivalents at lower temperatures. A generic approach to disinfection might not be helpful due to the availability of different meat types and cuts, and variation in procedures used in cutting plants and at post mortem. Lastly the Committee was opposed to the use of chemical disinfectants.

Hepatitis E
10.1 At the Chair's invitation Dr Brown presented paper ACM/818. He reminded Members that 12 months ago the ACMSF considered a discussion paper which assessed the risk of acquiring hepatitis E from the food chain. At this meeting Members concluded that whilst the foodborne risk was low, the FSA should revisit its advice on cooking of meat and recommended that all pork and pig products should be cooked properly.

10.2 Dr Brown outlined UK epidemiological surveillance studies carried out in 2003-5 and summarised the findings of work to investigate risk factors for hepatitis E. He also outlined new research on pigs and thermal stability of hepatitis E. He concluded that in the UK the route and associated risk factors for acquiring infection of hepatitis E had not been established and further studies were needed. He added that the previous ACMSF recommendations (paragraph 10.1 refers) were still appropriate.

10.3 Members queried whether the percentage prevalence of hepatitis E infection in the male population over 65 years had changed. Dr Brown explained that this was difficult to assess due to a lack of sero-prevalence data for the UK. He added that there were a high proportion of unknown case histories which reflected difficulties associated with obtaining this type of information. Members recognised that there was a lack of information available on hepatitis E survival in foods and identified a need to examine the prevalence of hepatitis E in pig products available in the UK. Epidemiological data was also limited in scope. Members discussed the presented information on travel and non-travel associated cases. Dr Brown agreed to clarify which patients were contacted by telephone.
Action: Dr Brown

10.4 In summary the Chair concluded that there were many gaps in the epidemiological and foodborne data available for hepatitis E. Members agreed that ACMSF advice remained that pork and pig products should be cooked thoroughly.

Epidemiology of Foodborne Infections Group (EFIG) and ACMSF sub-groups
11.1 At the Chair's invitation Dr Hilton (Chair, EFIG) introduced paper ACM/819 which updated Members on the most recent meeting of the Epidemiology of Foodborne Infections Group held on 19 October 2006. She reviewed animal and human data for the first six months of 2006, and briefed Members on trends on VTEC O157 in England and Wales. Other issues considered by the Group included a paper on the Co-ordinated Local Authority Sentinel Surveillance of Pathogens (CLASSP) study which involved simultaneous collection of data on Salmonella and Campylobacter from poultry meat and humans. HPA also presented papers on trends in the most common sub-types of non-travel-associated Salmonella Enteritidis, Salmonella Typhimurium infection in England and Wales from 1991-2005 and an update on human listeriosis in the UK.

11.2 Members welcomed the paper and noted that successful control measures had resulted in a decrease in animal carriage of serovars that are common in humans, including Salmonella Typhimurium. Mr Gayford commented that, in general, the number of Salmonella reports had fallen. Professor Piddock informed Members that MLST typing for Salmonella was discussed at a recent conference in Canada. Members suggested that the function of typing schemes should be defined and recognised that typing supported the implementation of practical controls.

Committee sub-groups

Working Group on Surveillance
12.1 At the Chair's invitation Mr Kyriakides (in the absence of Professor Humphrey) informed Members that the Group last met on 28 September to consider a draft survey report on Salmonella in non-UK eggs (information paper ACM/822 refers). The Group provided comments on the results and presentation of the data. A further meeting was scheduled for January 2007 to consider other FSA surveillance activity.

Newly-emerging pathogens
12.2 In the absence of Professor Hunter, the Chair reported that there had been limited activity via the message board as no major threats to the food supply had been identified over the period in question.

12.3 Mr Gayford reminded Members that Defra had sought comments from the Committee in response to its consultation on the implementation of EU Directive 2003/99 on the Zoonoses Monitoring Regulations 2006. He explained that this legislation provided powers of entry into premises for rapid sample collection to support surveillance of emerging zoonoses. He sought the views of the ACMSF on whether its Newly Emerging Pathogens Group would be willing to provide advice on emerging foodborne infections to support monitoring and surveillance of emerging infections. Members confirmed that provision of such advice fell within the remit of the Group.

Dates of future meetings
13.1 The Chair brought to Members' attention paper ACM/820 which listed the dates for meetings scheduled for 2007. She reminded Members that all meetings were open to members of the public.

Any other business

14.1 Professor Piddock asked whether there were any microbiological grants available under this year's postgraduate scholarship scheme. Dr Hilton explained that whilst microbiological grants had been awarded in previous years, none had been made in the current year where the focus had been on nutritional issues. Decisions about grants in 2008 had not yet been made. Professor Piddock commented that this scheme might be a suitable vehicle for funding further work on listeriosis. Dr Hilton agreed to provide an information paper on microbiological topics covered under the postgraduate scholarship scheme.
Action: Dr Hilton

14.2 The Chair informed Members that Professor Gasson, Professor Hunter, Ms Lewis, Dr Millership, Mr McMullin and Professor Williams had been re-appointed to the Committee. She also informed Members that Professor Piddock would be resigning from the Committee at the end of her term of appointment in March 2007. She thanked these Members for their commitment and contributions to the ACMSF.

14.3 The Chair also informed Members that she had recently attended a seminar and dinner for the Chairs of Advisory Committees. She reported that at this meeting the Best Practice Agreement was discussed. She added that the Chairs had also identified the need for greater input from social sciences in the work of the Advisory Committees.

14.4 Dr Foster informed Members that the interviews for the post of ACMSF Chair took place on 7 November. Ministers were currently being consulted on the appointment.

Public questions and answers

15.1 The Chairman invited the members of the public present to ask any questions they might have on the work of the Committee, or to make any observations.

15.2 Mr Derek Armstrong (MLC) outlined issues relating to the cooking of pork commenting that there was no direct evidence to indicate that pork was a vehicle for infection for hepatitis E in the UK. He added that the over 65 age population group were not considered to be a major consumer of pork. He discussed the stability of the hepatitis E virus and queried whether the risk from eating pork meat was the same as that associated with the consumption of offal. Lastly he identified the need for a more formal risk assessment.

15.3 Dr Brown confirmed that transmission routes for hepatitis E were unknown and that published information on foodborne risks associated with hepatitis E was limited. Therefore the Committee had focussed its attentions on epidemiological studies. He agreed that further work was needed but considered that a precautionary approach to advice on cooking of pork should be adopted until more information is available.

15.4 Mr Alan Long (VEGA) commented on several issues including toxoplasmosis, disinfection of knives and the need for a representative of the Veterinary Public Health Association on the Committee. The Chair informed him that ACMSF members were appointed on the basis of their individual expertise and not to represent particular organisations. In response to a comment about the handling of Bowland dairy incident Dr Hilton confirmed that this was not viewed as a microbiological issue and fell outside the remit of this meeting.

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