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U.S. Department of Health and Human Services

Animal & Veterinary

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The Turkey Industry by Hector Cervantes, DVM, M.S., University of Georgia

DR. CERVANTES: I want to start by thanking Dr. Cray and Dr. Thesmar from the NTF for asking me to speak on their behalf. They are having the leadership conference meeting in Washington, D.C. starting Sunday, so she is pretty tied up with that. She knows how I feel about the subject, so get ready for another sermon on the goods of antibiotics.

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Let me start by saying NTF believes the NARMS program fulfills an important mission. NTF also believes all three arms of NARMS program are collecting important information on antimicrobial resistance. NTF believes data on antimicrobial resistance can be very useful when analyzed, interpreted, and used appropriately.

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These are some of the industry concerns that I know exist right now within turkey production veterinarians. In most recent surveys, the lack of effective antimicrobial and antiprotozoal medications has ranked the number one issue of concern.

I mention that because with the removal of Baytril, we lost our most effective medication against colibacillosis which is our most common disease in poultry, as Dr. Cummings mentioned. When we lost the last effective medication we had for blackhead, we have basically no treatment left.

The potential removal of antibiotic feed additives classed as growth promoters has certainly also ranked high in the list of concerns of turkey production veterinarians because we know that in addition -- that the reason they improved the growth rate is because they keep a healthier intestinal tract. 

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Another concern of NTF has been that it seems like antimicrobial resistance data from the NARMS programs has been used in the past at least to incriminate veterinarian antimicrobials in the development of resistance in human isolates.

Furthermore, regulatory action has also been taken against veterinarian antimicrobials based on antimicrobial resistance trends from NARMS. You all remember what happened with enrofloxacin two years ago.

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NTF would like to see NARMS data be used not only to incriminate veterinarian antimicrobials, but also to exonerate them or rectify mistakes made in policy. For example, what has NARMS data shown in the years following the ban of enrofloxacin? That is a legitimate question. 

Based on this data, has the U.S. ban of enrofloxacin used in poultry accomplished its goals as far as public health? I will let you be the judge of that.

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That is data from NARMS 2000 Executive Report which is the last one I could find on FDA’s website.

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If NARMS data shows that the ban of enrofloxacin for poultry has not made a measurable positive difference in human Campylobacter resistance to ciprofloxacin, then the logical question is why not use NARMS data to reinstate the license to sell and use enrofloxacin in poultry with the same stipulations previously required? Again, I think that is a perfectly legitimate question.

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Thousands of turkeys have suffered and died unnecessarily from bacterial diseases caused by organisms typically susceptible to enrofloxacin but not to the older “effective” antimicrobials, as Dr. Cummings pointed out. Because one reason we hardly ever treat flocks anymore is lack of effective medications.

This is inconsistent with our oath as veterinarians to prevent suffering and maintain the health of animals.

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Another issue that I see with NARMS is that it is much more focused on antimicrobial resistance in food-producing animals and poultry than in companion animals. In reality, or at least in my common sense mind, is that of the two distinct populations of animals, food animals and companion animals, companion animals would be a much more likely source of antimicrobial resistance than food-producing animals. 

Why do I say that? Because companion animals live in intimate contact with people. Therefore the possibility of acquiring live microorganisms from a companion animal is greater than from a cooked piece of poultry meat.

Companion animals are prescribed the same types of antimicrobials routinely used in human medicine. That is another issue.

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I will let you be the judge of these. You tell me which one would be a higher risk activity if exchange of resistant germs is your concern.

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The recent release of FDA’s Guidance for Industry number 209 “The Judicious Use of Medically Important Antimicrobials in Food-Producing Animals” has heightened the concern about the future of antibiotic feed additives classed as growth promoters by the turkey producers of this country.

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As Dr. Cummings mentioned, there are numerous benefits derived from the use of antibiotics in animal feed, such as the ones I am listing here, prevention of subclinical diseases, enhanced enteric health, improved flock performance, enhanced animal welfare.

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They reduce pathogen load. Hogs raised with in-feed antibiotics again had less pathogens than the ones without. By promoting health, they ensure healthier animals reach the processing plant. The ultimate beneficiary from all that is the consumer.

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The improvements in growth rate and feed efficiency reduce significantly the excretion of nitrogen and phosphorus into the environment while saving a significant amount of water and preserving millions of acres in their natural state that otherwise would have to be devoted to food production and crop production.

This aids significantly in reducing the carbon footprint related to the production of food animals.

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So are they growth promoters or is that a term that was coined before my time, back when we did not know about PCRs, we did not know about resistance? There were no concerns probably 60 years ago or 50 years ago. Or are they health promoters? Again, I will let you be the judge of that.

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This data came from DANMAP. There are the years. You can go online and get the same exact numbers that you see here. So it is pretty clear-cut undeniable that the so-called growth promoters were actually promoting health because there has been a 101 percent increase in use of therapeutics over this nearly ten-year period.

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I put this slide here just to show you that the increase of 101 percent was not due to a 101 percent increase in the animal population.  The animal population has barely increased, just only six percent.

If you look at the yearly milligrams of antibiotic consumed per kilogram of meat produced in Denmark following the AGP bans, we see that it clearly matches what happened on the use of therapeutic antibiotics in food animals.

So like I said, are they growth promoters or are they health promoters?

I am going to skip through some of these but I just want to let you know that there are plenty of clues that antibiotic resistance from antibiotic feed-additive use in particular is not impacting human health in a significant way.

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Avoparcin is the example that I am sure you are all familiar with where it was used extensively as a growth promoter in Europe, but not in the U.S. where VRE is a much bigger problem in the U.S. than Europe in spite of the lack of food animal production use of Avoparcin which is the veterinary counterpart. 

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This is in agreement with findings that indicate that the enterococcal infections do not cross infect from animals to humans and vice-versa. There is more than one reference to that effect.

There is also in agreement with research that indicates that VRE that is responsible for human infections are genetically different from those present in food animals.

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Virginiamycin was mentioned earlier today. Virginiamycin came under severe scrutiny in 1996 with the official launch of the human counterpart, Q-D or quinupristin-dalfopristin. However, if we keep in mind that virginiamycin had been used extensively as a growth promoter in food animals in North America for many years, that prior to the introduction of Q-D, an extensive sensitivity study survey conducted with E. faecium isolates from North American medical centers, we found that basically there was no resistance prior to the introduction of the human drug.

So after many years of virginiamycin use in food animals there is virtually no resistance in the human population.

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I am sure some of you will remember this paper published by researchers from CDC that again attempted to show transmission of streptogramin resistant E. faecium to people. They could not document this. 

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More recently, there was another attempt by researchers at the Marshfield Clinic and the Bloomberg School of Public Health, and again they completely failed to show that, even though they compared hospitalized patients with vegetarians, but even at that, they could not show any detectable transmission of E. faecium to people.

So again, the resistance may be in the raw chickens, but apparently it is not finding its way into the people.

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I am just going to close by saying that we already have a good number of safeguards in place, post approval monitoring of new antimicrobials, dossier (sic) submitted to FDA for efficacy, safety for humans, animals and the environment.

Regulations, at least for now, explicitly preclude use of extra-label drugs in feed.

Feed mills are audited by FDA on a regular basis. We have a residue monitoring program, as you well know. And, of course we have NARMS which, like I said is a very valuable tool.

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The American Veterinary Medical Association in cooperation with all the specialty groups has issued in cooperation with FDA, judicious guidelines for the use of all antimicrobials in veterinary medicine including companion animals and food animals.

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Keep in mind that judicious use by no means means no use.

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Additionally, the Food Animal Veterinary Specialty Group would just like to report the American Association of Avian Pathologists has developed, with significant input again from AVMA and FDA-CVM, its own set of judicious guidelines and have made them available to all their members.

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Dr. Cummings mentioned this risk assessment for virginiamycin. There are several being done for antibiotics of most concern for human health. Like we showed from -- or we learned like he mentioned from the European experience, we need to weigh out the consequences of banning antibiotics in food animals for political or precautionary reasons as they may have effects opposite to those intended.

Someone else mentioned as well, Dr. Apley, I believe, that we are good at always looking at the risk of continuing a practice, but we never look at the risk of discontinuing that same practice, which in some cases may be greater than the risk of continuing or maintaining the status quo.

With that I will conclude and thank you for your attention.

(Applause)

DR. FRYE: We will go ahead and continue if Tom is out there. Tom Shryock from Elanco to finish up sort of the industry talks. Tom, let me get your talk up here.

Also for the presenters, Joann would like to ask your cooperation and help her prepare the talks for publication on the web for those of you who have not. There are release forms to be signed and also she was asking if the speakers would not mind to do the PDF conversions. I think most people prefer that. Then email them to Joann. She has her card there with her contact information. Thank you.