THE ADVISORY COMMITTEE ON THE MICROBIOLOGICAL SAFETY OF FOOD REPORT
ON:- "ANTIBIOTIC RESISTANCE AND FOOD SAFETY"
Response of the National Office of Animal Health (NOAH)
Introduction
- The National Office of Animal Health (NOAH) welcomed the publication on 18th August 1999
of the long awaited report from the Advisory Committee on the Microbiological Safety of
Food (The Committee or ACMSF) report on "Antibiotic Resistance and Food Safety"
(The Report). We recognise that its long gestation of three years was the result of the
considerable research, discussions and deliberations of the Committee.
- The duration of these deliberations was at a time of considerable change in the
philosophies surrounding the use of antimicrobials by both the medical and veterinary
professions, as well as alterations in European and national legislation. Many of these
paralleled the requests by the Advisory Committee on the Microbiological Safety of Food
(ACMSF) Working Party for information and advice, as well as those of the House of Lords
Select Committee on Science and Technology, the Veterinary Products Committee, the EU
Commission Report, the Report of the Committee on Veterinary Medicinal Products, The World
Health Organisation report and many other national and international bodies. In
consequence many of the changes made in the recommendations of the Report were already in
progress by the time it was published.
- On its publication, NOAH immediately welcomed and recognised the thoughtful and well
argued approach adopted within the Report and that the situation required evolution not
revolution (NOAH Press Release 18/8/99 - Appendix 1).
- One major recommendation highlighted by NOAH at the time of the Report's publication in
August 1999 was the creation of Responsible Use of
Medicines in Agriculture (RUMA) Alliance of which NOAH is a founder and active member.
This organisation had already been in existence for 18 months by the time the Working
Party's report was launched and involved organisations representing all the links within
the chain from "farm to fork". It has the declared aim of promoting the use of
best practice within the livestock industry and thereby reduce the need for antimicrobial
usage. RUMA has already published two sets of
guidelines on "Responsible Use of Antimicrobials", one in poultry and the other
in pig production (June 1999): similar documents for cattle and sheep are in production.
Patterns
of Antibiotic Resistance in Bacteria Isolated from Farm Animals. (Chapter 3)
- In our evidence to the Working Party we declared that "It is thus to be expected
that the use of a particular antimicrobial treatment in a human or animal population will
have the potential for antimicrobial resistance. The degree to which this occurs
varies..." (NOAH Submission to ACMSF Working Party Paragraph 26). This is well
illustrated in the Report Chapter 3.
Evidence of the Food Chain contributing to Human
Infections with Antibiotic-Resistant Micro-organisms (Chapter 6)
- In our evidence to the Working Party we pointed out "While transfer of resistance
has been shown to exist particularly between enteric bacteria, antimicrobial resistance
transmission between different host species is not well documented although it must in
theory be a possibility. However such transfer from farm animals used for food to humans,
even when it exists, cannot be the main cause of antimicrobial resistance in man".
(NOAH submission to ACMSF Working Party Summary Paragraph 5).
- The fact that this chapter mainly focuses on the trends in reports from humans and
animals indicates the difficulties in investigating this area. The relatively small number
of outbreaks of human disease which have been proved to have been transmitted from animals
to food to man, despite, we suspect, a very large number of investigations, further
confirms this point. It might be suggested that the need to mainly use indirect evidence
for the link between antibiotic resistant organisms in man and animals does indicate that
the occurrence of this transmission is, at its worst, relatively infrequent.
- NOAH would agree that the amount of material showing direct transmission of pathogens
and commensal organisms to humans is less than for food exposure (Report Paragraph 6.90).
This obviously reflects the amount of direct exposure of the overall population to animals
as opposed to food. It also suggests that the ability for disease to cross directly to
humans is low in the normal healthy individual and so the dangers of contracting an
infection are less than from another human being.
- However it is inevitable that, even with the best husbandry methods, animals will
contract diseases, some of which will be zoonotic. It must be recognised that it is
incumbent upon, and the responsibility of, NOAH members and the veterinary profession to
provide appropriate therapy including use of antimicrobials as well as husbandry and
management changes to bring under control any such disease conditions and outbreaks. This
should include research by the animal health industry into the potential for alternative
vaccines to reduce the need for therapeutic treatment of disease with antibiotics. It also
will reduce the possibility of food borne disease and prevent potential welfare concerns.
Fluoroquinolones
- NOAH understands the major concerns over microbial resistance to this group of
antimicrobials. In our written Submission to the ACMSF Working Party, we dealt with these
products and the initiatives being undertaken at that time (Submission Paragraph 33) and
subsequently. We have read the Recommendation 6.120 endorsing that of the House of Lords
Select Committee on Science and Technology that "the veterinary profession must
address the problem of overuse of fluoroquinolones".
- Campylobacter are the most frequently reported cause of human infectious
intestinal disease in the UK and the incidence is continuing to rise. However most of the
evidence for fluoroquinolone resistance in these micro-organisms comes from production
systems abroad (see Paragraphs 6.44, 6.45, 6.46, 6.47). Some of the countries where
ciprofloxacin resistance is being reported in Campylobacter isolates are
contributing considerable quantities of poultry and other meat to United Kingdom tables.
Resistance of similar origin has also been seen in some of the Salmonella species.
As far as can be seen the only major mention to this real and potentially increasing
problem is in Paragraph 12.34.
- This recommendation is suggested as being put into effect for the medium/long term,
although the Report recognises that this is already a major cause of infection. The
recommendation as written is surely not providing a satisfactory level of emphasis when
the literature suggests that food reared in some countries should be considered at least
equally, if not more, important in terms of antimicrobial resistance in food products than
from indigenous produced supplies. It also does not take into account the increasing
amounts of imported food, often from Third Countries, which are now being consumed in the
United Kingdom.
- In our Submission to the Working Party we did indicate the international implications of
any recommendations on antimicrobial usage (Submission ACMSF Working Party Paragraphs 34 -
36). Since writing our submission there is at least one other example of UK farmers being
put at an economic disadvantage, this time on welfare grounds. Thus there would appear to
be a major increase in pigmeat imports following the Sow Stall and Tether ban which came
into force at the start of the year and has increased the costs of rearing in the United
Kingdom. As far as we can see, these economic considerations and the need for a level
playing field in terms of human health, do not appear to have been given sufficient
emphasis in the general coverage of the Report or in the Summary and Overview Paragraph 9,
Conclusions and Recommendations). This appears slightly at odds with the very
international approach taken in the literature studied and used in this Report. NOAH
considers that this potentially extremely important source of foodborne disease and
antibiotic resistance in Britain should be quantified and that this point should be
urgently addressed. We also believe that consideration should be given as how best to move
forward this important problem on a global basis and not just nationally or in Europe.
- In no way is the above a suggestion to divert the animal health industry from its own
responsibilities on the use of fluoroquinolones in food producing animals. We understand
the concerns and to this end NOAH has produced a Briefing Document (No 18 The Use of
Fluoroquinolones in Animal Health - Appendix 2). In addition member companies who
produce these antimicrobials have been acting to ensure the responsible use of
fluoroquinolones, even going as far as to include this need in their advertisements.
- In the report there is allusion to the ability for food to become contaminated with
foodborne pathogens which may be antibiotic resistant as well as their ability to survive
due to poor or inappropriate cooking methods (e.g. Paragraph 6.116) thus allowing those
consuming the foods to be exposed to infection. It is most unlikely that any food from a
natural source will ever be completely without the possibility of contamination. While
this was possibly outside the remit of the Working Party, it does need to be addressed at
least in terms of education both during slaughtering and subsequent processing. As
important, education needs to be directed at the consumer on a continuous basis: domestic
science should be a core curriculum subject.
The Use of Antibiotics in Farm Animals
(Chapter 8)
- NOAH understands the difficulties encountered when attempting to obtain useful data on
the amounts of antimicrobials used in food animal production. (Paragraph 8.3). This is
because of various methods of accounting for such compounds. However quantities are not in
themselves of great value as their potency varies and so it is possible for the weights of
antibiotics to be reduced by the increased usage of higher potency antibiotics.
- NOAH endorses the sentiments made in Paragraph 8.22 that antimicrobials should never be
a substitute for good husbandry and this was included in our Submission to the ACMSF
Working Party (Paragraph 4).
- NOAH is pleased at the positive mention for the work of RUMA (Paragraph 8.40) of which it is an enthusiastic
member. Mention has already been made above about the already published RUMA Guidelines on the Responsible Use of
Antimicrobials in poultry and pigs. Early in 2000 similar guidelines will be published for
Cattle and Sheep. This is just the start of the Alliance’s work which will continue
and is likely to involve methods for assessing progress in responsible usage etc.
Medicated
Animal Feedingstuffs (Chapter 9)
- NOAH are pleased that the Report tacitly accepts the need for the use of in-feed
antimicrobials. It does provide in cases of illness in groups of animals, the most humane
method of supplying medication to them. We are pleased that the Report has recorded the
considerable amount of legislation which governs this activity. We acknowledge that the
situation cannot remain static and this has resulted in NOAH together with the World
Veterinary Association, the International Federation of Agricultural Producers, the Global
Animal Health Industry Association (COMISA) producing a set of prudent use of antibiotics
guidelines in 1999 (Appendix 3). These are concerned with the responsible use of
antimicrobials and encouraging best practice animal husbandry to reduce the need for
antibiotic treatment. This has been followed by the guidelines produced by RUMA.
The Use of Antibiotics as Growth Promoters in
Food Animal Production (Chapter 10)
- NOAH maintains its position that usage of such substances is restricted to substances
which are not used in the treatment of disease in humans or animals or are related to
human compounds in use at that time (Submission to ACMSF Working Party Paragraph 18). We
consider it would be wrong to ban compounds which have at present no foreseen use in human
medicine. All these products have been through the rigours of licensing. In addition we
still maintain that the almost "accepted truth" that "the overuse of growth
promoters in intensive farming has led to an increase in resistance to human
medicine" (Submission to ACMSF Working Party Paragraph 27) is at the very least
unproven. Further support for our position is provided in the recent Leading Article in
the Journal of Antimicrobial Chemotherapy (Phillips, I. {1999} The use of bacitracin as a
growth promoter in animals produces no risk to human health. Journal of Antimicrobial
Chemotherapy 44 725 - 728).
- Such an extension in the banning of digestive enhancers cannot be justified unless there
is proven evidence of the development of antibiotic resistance. We believe that the
Recommendation for the suspension of use of some of the antimicrobials used as digestive
enhancers has been undertaken under the shield of the precautionary principle (Report
Paragraphs 10.28, 10.29, 10.30) and is not justifiable on current scientific knowledge.
The products all went through the process of registration and most have been successfully
used for many years in the United Kingdom as well as abroad. If this precautionary
principle premise is used in the same way in the future, it may well preclude the use of
many other compounds both known and unknown and could perhaps include probiotics, enzymes,
vitamins and mineral preparations.
- While advocating the two stage approach to withdrawal of antibiotic growth promoters,
the Working Party did not address those products which might be used as replacements for
them. However in places in the Report, some possible indications, are given. Thus under
fermented foods (Paragraphs 6.86 to 6.89), where only limited work appears to have been
undertaken, antibiotic resistance can occur although their contribution to overall
resistance or the potential to exchange resistance genes is unknown. While Recommendation
6.122 states that it is extremely important that there is continued surveillance of those
growth promoters still authorised, the suggestion that antibiotic susceptibility and
non-pathogenicity are essential criteria when choosing probiotics or other alternatives is
hidden away within the text (Paragraph 6.89).
- Many possible replacements for growth promoters do therefore have the potential for
producing resistance. They also often make medicinal or quasi-medicinal claims and yet
many do not fall within the licensing regime. This may well be a case of throwing the baby
out with the bath water and then refilling the bath with dirtier water of ill or non
defined content.
Research on Antibiotic Resistance in Relation to Food Safety (Chapter
12)
- It is to be regretted that research into the area of antibiotic resistance involving
food safety is not receiving much publicly-funded research. The priorities for such work
may change with the establishment of the Food Standards Agency. However we do consider
that a priority piece of research work is to place antibiotic resistance into context (see
Paragraph above). This would then allow its importance to be evaluated in the overall
context of medical research as well as that of food.
- While we appreciate that foreign travel is a significant risk factor for infection with
certain antibiotic-resistant pathogens and does require further study (Paragraph 12.9), we
believe that, as much of our most commonly consumed foods is now reared and originates
outside the United Kingdom and even outside Europe, surely funding should be made
available for determining the degree of this risk and how best it can be contained (see
Paragraph 10 above). While it is right to require stringent control of veterinary usage of
antimicrobials in farm animals indigenously, similar controls must also be imposed in
other areas from which we are obtaining an increasing amount of our food (Paragraphs 13
and 14 above). Thus while there is some European national surveillance on bacterial
resistance (Paragraph 12.15) this work needs to be extended to involve foods being
imported as often such foods are packed or repackaged within the EU and then can be
labelled as being from the EU.
- While UK researchers are looking at the influence of antibiotic resistance and more work
has been called for (Paragraph 182), there are probably even more pressing needs to look
at the "best practice" approach to the treatment of disease outbreaks which
inevitably will occur however effective the management system. This is not work which
could be undertaken by NOAH members because of the inevitable suggestion would be made
that the companies would have a vested interest.
Conclusion
A. NOAH welcomes the ACMSF Working Party Report and believes that
it is a very useful contribution to the debate on food safety at a time when the Food
Standards Agency is in the process of being created.
B. NOAH believes that there is a need to place into context the
relative importance of antimicrobial resistance in animals and foods in the overall
context of human disease due to antibiotic resistant organisms.
C. NOAH also believes that, as an increasing proportion of some
foods consumed in the United Kingdom is being imported including from Third Countries, the
level of contamination (or not) with antibiotic resistant micro-organisms needs to be
addressed most urgently.
D. NOAH welcomes all moves to improve the effective usage of
antimicrobial agents. However it must be on the basis of a level playing field and not be
at such an economic cost to UK producers that it allows the increased importation of foods
from countries which may have less regulation on antibiotic usage.
E. Consideration must be given to the reduction of the potential
for contamination with foodborne micro-organisms after animals are slaughtered. NOAH also
believes there is a need for continuous education of the consumer on how to avoid exposure
to foodborne pathogens.
F. NOAH cannot agree with the implied suggestion that digestive
enhancers (growth promoters) should be banned under the precautionary principle.
G. NOAH is concerned that new technologies designed to replace
antibiotic growth promotion are not being regulated to the same high standards. In almost
all instances they are not being as rigorously researched as were the previously licensed
antibiotic growth promoters. NOAH thus urges MAFF
to ensure that all such products are regulated according to EU and UK law. The ACMSF
should consider the promotion of such regulation as a matter of concern. |
