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Release No. 0082.04
Printable VersionPrintable Version
Office of Communications 202-720-4623

Transcript of Technical Briefing on Animal Health Issues With Dr. Ron DeHaven, Chief Veterinary Officer, Dr. Bob Hillman, Texas Animal Health commission, Dr. Nancy Cox, Centers for Disease Control and Dr. Steve Sundlof, FDA's Center for Veterinary Medicine Washington D.C. February 23, 2004

MR. JIM ROGERS: Good morning. This is Jim Rogers with the Animal and Plant Health Inspection Service of the U.S. Department of Agriculture. Today we have Dr. Ron DeHaven, deputy administrator for our Veterinary Services Program. Also on the line today we have Dr. Bob Hillman of the Texas Animal Health Commission, Dr. Nancy Cox of the Centers for Disease Control, and Dr. Steve Sundlof of the Food and Drug Administration.

We're going to have a discussion today about avian influenza as well as a little discussion on BSE and the results of the Secretary's Advisory Committee on Foreign Animal and Poultry Diseases.

At this point, I'm going to turn it over to Dr. DeHaven. He will go ahead and discuss this now, and later on we have a short question and answer session.

DR. RON DEHAVEN: Thank you, Jim.

As mentioned, the update today is really two-fold-- to talk about the evolving avian influenza situation in Texas; and then as many of you are aware we have the International Review Subcommittee Report that was delivered several weeks ago. That report has now formally been transmitted to the Secretary with some recommendations from her Secretary's Advisory Committee. So I'll touch on those as well.

As to the avian influenza situation, many of you may have read in the news this morning that we have been working with the Texas Animal Health Commission on an avian influenza outbreak. Although preliminary clinical information suggested that we were dealing with a low pathogenic avian influenza, we're reporting this morning that this flock of chickens is in fact positive for highly pathogenic avian influenza.

This is a flock of chickens in Gonzales County, Texas, on premises about 50 miles east of San Antonio. We received the confirmatory laboratory results at about 2:00 this morning. This premise is under state quarantine, and the flock of approximately 6,600 broiler chickens was depopulated on Saturday by the state of Texas.

The epidemiological investigation is underway, and we're looking for any connections between this and any other flocks, both in terms of source of the infection to this flock as well as potential spread from it. We have established surveillance testing within a 10-mile radius, and as part of that epidemiological investigation we do know that birds from this flock went to two live bird markets in Texas. Testing has been done at those live bird markets. Preliminary results at the Texas laboratory are awaiting confirmation, but preliminary tests suggest that some of the birds from this index flock in Gonzales County were found to be positive at two of those live bird markets.

Both of them are under hold order. One has been depopulated, and the other is being depopulated.

We, on the USDA side, are working very closely with the state of Texas, and I certainly have to say the Texas officials have done an exemplary job of handling this issue up to this point. By quickly identifying and depopulating this flock they quickly and effectively reduced the chances for spread of infection -- which both from an animal standpoint and any potential human health standpoint, that's very important.

So I appreciate all that they've done and with disclosure of this high path incident or declaring this to be high path we have now activated our federal response system and will be working along with the state in establishing an incident command post this morning in the area of this positive flock.

Just a real brief history. It started on February 17 with routine surveillance samples that were sent to the Texas Veterinary Medical Diagnostic Laboratory where they received a preliminary positive for an H5 virus, AI virus. That then prompted follow-up on-site investigation at the premises. A foreign animal disease diagnostician was dispatched by the Texas Animal Health Commission to get additional samples and information from the farm.

As I mentioned, the preliminary clinical signs in this flock were thought to be consistent with low path avian influenza. We now have data obtained subsequent to that that suggests that there has been some moderate mortality in this particular flock.

Samples were submitted at that point as well to our National Veterinary Services Laboratories, or NVSL, in Ames, Iowa, where they confirmed an H5 virus, actually confirmed it to be an H5N2, and then also did the DNA sequencing. And I'll talk a bit more about the DNA sequencing that is the basis for us calling this "high path" today.

Since H5 and H7 avian influenza strains can either be low path or high path, we initiated the additional tests. And as I mentioned earlier this morning completed the genetic sequencing. And it's that genetic sequencing information that is causing us to call this a highly pathogenic avian influenza virus.

Additional tests are ongoing at NVSL to confirm the pathogenicity, but again by international standards that are established by the OIE or the World Animal Health Organization, the sequence that we have determined with this virus with the DNA sequencing would be consistent with a high path virus.

Other tests that I'll mention at this point where we inject the virus into susceptible chickens at this point would not suggest a very highly pathogenic virus; but again, it's based on the results that we have with the sequencing that we're making that call today.

Just a little background and education on avian influenza viruses. Certainly this time of year we commonly see AI viruses not uncommonly like we see this time of year people getting the flu, which are caused by viruses of the same family. We identify them by subtypes based on the presence of proteins on the surface of the virus. These proteins, called hemagglutinin and neuraminidase, are abbreviated simply as H and N. There are currently 15 known H subtypes and 9 known N subtypes, and so they can occur in any combination; 9 times 15, potentially 135 different combinations of the H and N subtypes.

We know that H5 and H7 viruses can become highly pathogenic even if they start out as a low pathogenic form. And so any time we find an H5 or an H7 they are further classified or further testing is done to classify them as either highly pathogenic or low pathogenic. And again, that pathogenicity relates to their ability to cause disease and mortality in birds.

Two ways to declare a particular virus highly pathogenic. As I mentioned, one is by international standards that goes on the genetic sequencing of the virus. And it's on that basis that we're declaring this virus recovered in Texas as highly pathogenic.

The other way, the other pathogenicity testing, is determined by inoculating healthy chickens and monitoring their immune response and mortality over the course of a 10-day period. Those tests are still pending on the Texas virus at NVSL.

And in fact they very well could be low path. We simply don't know, as we're very early in that level of testing.

Just as kind of background of some of the other viruses that you may have been aware of -- the two flocks in Delaware are a low pathogenic version of H7N2. The virus that currently is affecting Asia is a highly pathogenic H5N1. We also very recently had a positive flock in Pennsylvania that was an H2N2, and we're presuming at this point that it is low path.

And I should also mention that the last time we had a highly pathogenic avian influenza virus in the United States was in the 1983-'84 timeframe. It affected commercial poultry in both Pennsylvania and Virginia, and it was a high path H5N2.

Well, unlike BSE, avian influenza in fact is a very highly contagious disease. Exposure of poultry to migratory waterfowl seems to be the most likely cause or certainly the ongoing reservoir of infection. But once established the movement of poultry, poultry equipment and people from one infected premise to another pose the risk of introducing avian influenza into other premises and certainly into commercial poultry.

Once it's in a flock, the spread of the disease can occur from bird to bird by direct contact and then as I mentioned typically from farm to farm through people, equipment and other mechanical means of transmitting the virus.

We would in that respect then encourage all poultry producers and everyone involved in the poultry industry to practice good biosecurity making sure that equipment such as manure-spreading equipment, vehicles, egg flats, crates, people and their clothing and their footwear are properly cleaned and disinfected before not just going from premises to premises but also between houses on the same poultry premise.

Any poultry producer that notices an increase to mortality we would encourage them to report those losses to their veterinarian, to the appropriate USDA extension agent, to their state animal health agency, or certainly they can contact us as well.

As to the threat to potential human health, certainly in some unusual circumstances strains of high path avian influenza can be infectious to people. Human infections with AI viruses occur under natural conditions, and certainly that has been documented recently in Asia with the H5N1 strain. A similar H5N1 was isolated in Hong Kong in 1997. It was highly pathogenic for chickens and caused a limited outbreak in 18 people.

Since mid-December of last year a growing number of Asian countries have reported an H5N1 highly pathogenic virus in chickens and ducks.

We are working very closely with the Department of Health and Human Services and specifically with the Centers for Disease Control and Prevention to address any potential human health impacts of this current situation in Texas. To that end, Secretary Veneman spoke by phone this morning with both Dr. Julie Gerberding, the directors of the CDC, and with her counterpart Secretary Thompson at HHS.

We presently have no evidence of any human health implications of this high path virus in Texas, but I'll certainly let the CDC representative speak to that issue in just a moment. In the meantime, I would simply mention that the most important action to prevent the spread of this disease to other poultry or in fact if it has a human health implication to people has already been taken. And that is, to depopulate the infected flock.

With that, let me turn to Dr. Nancy Cox, the chief of the Influenza Branch at the CDC, regarding follow-up activities that they will be conducting.

Dr. Cox.

DR. NANCY COX (Chief, Influenza Branch, CDC): Yes. Thank you very much.

As you've already heard, avian influenza viruses usually do not infect humans. And the ability of avian influenza viruses to transmit from person to person appears to be very limited, even if humans do become infected with an avian influenza virus. And past experience with H5N2 viruses have indicated that there is a low threat to public health.

If we go back to the 1983, '84 situation there was an attempt to monitor transmission of the H5N2 highly pathogenic viruses to humans. And what was observed was that transmission and replication of the influenza viruses in humans did not occur.

Nevertheless, as we move forward at this particular situation, we must keep an open mind and really monitor the situation as we go. So what we plan to do at CDC and what we've already begun is to work with local and state health officials to share information and to move forward to monitor the risk to human health.

Now as the H5N1 situation had evolved in Asia, CDC has put together a number of interim guidance documents which we believe will be extremely helpful for the current situation with just a little bit of modification. So we already have guidance documents on, for example, advice for travelers, advice for people who might have come in contact with infected birds. We'll be advising those individuals to see a doctor if they develop influenza-like illness; that is, if they develop a fever with respiratory symptoms after coming in contact with these birds.

We'll be advising people to monitor their health for 10 days if they've been involved in a culling operation or other activities to do with the current situation and obviously to consult with a healthcare provider if they become ill within that 10-day period.

We also will be very interested in analyzing viruses from these particular outbreaks to determine if the viruses are sensitive to the influenza antiviral drugs that are currently available. This will be important so that we understand how best to treat anyone who might become infected with these viruses.

So we will be basically mounting a full-court press to monitor the threat to human health and to put in place guidelines that can be used by physicians, by consumers and others who might be interested in what are the specific recommendations for what they should do.

I think with that I'll close and open the floor for questions.

DR. DEHAVEN: Nancy, before we do that, and thank you very much -- we wanted to go on with a quick overview of some ongoing activities with regard to our BSE situation, and then we would open it up for questions for both issues at the conclusion of that.

So with that explanation let me again give a very brief update of some activity since we held our last media briefing as it relates to BSE.

As you know, we conducted and in fact have completed a full epidemiological investigation into that situation and for those of you that would like an update on the investigation and our findings that can be found on the APHIS website at Since that time we have taken further steps to protect public health and our nation's livestock, and these would be measures in addition to some of the procedures and activities that have been in place for as long as a decade.

As you know, the Secretary announced on December 30 a number of actions to include: prohibiting nonambulatory cattle from entering the human food chain; a rule was published declaring that specified risk materials or those tissues or portions of the carcass that represent the most risk from cattle over 30 months of age will be excluded from the human food supply. There was a rule published expanding the prohibition of central nervous system tissue in advanced meat recovery products; the rule that prohibits the use of air injection stunning equipment at slaughter, and a notice to FSIS inspectors that they will not mark normal slaughter cattle that have been tested for BSE as "inspected and passed" until a negative test result had been obtained on any of those animals.

Also, knowing that we are going to need quick turnaround samples for our surveillance program in the future, APHIS since January 9 has been accepting license applications for BSE test kits and no doubt will be using one or more of those kits in the future. In fact, we have been using one of the test kits as part of our epidemiological investigation with testing some of the animals that were sacrificed as part of that investigation.

Additionally, the Food and Drug Administration has made some decisions about animal feed, and we have Steve Sundlof, the director of the Center for Veterinary Medicine at FDA on the call-in. He's available to answer questions that you may have with regard to feed or feed restrictions.

The main point of the follow-up then is to address the recommendations coming from the Secretary's Advisory Committee on Foreign Animal and Poultry Diseases. As you know, Secretary Veneman had commissioned a review of international experts to conduct a review of our investigation and to make recommendations to us, and they did so as a subcommittee of the Foreign Animal and Poultry Diseases Committee.

That committee then in turn has commented on the subcommittee report in a letter to the Secretary and a full copy of that letter will be posted on our APHIS website. In the meantime, I just wanted to share a few highlights with you from the Advisory Committee recommendations, along with comments on where we are in terms of the status of some of the recommendations.

As part of their letter, the Advisory Committee recognized several positive findings by this International Review Subcommittee. These included a comment and a compliment on the full disclosure and access of USDA personnel to the subcommittee as they did their investigation as well as the open and transparent process of the investigation that has been undertaken by the USDA.

They were complimentary of the thoroughness of the epidemiological investigation and the good cooperation that exists between U.S. officials and our Canadian counterparts.

They considered to be comprehensive and appropriate the tracing and recall of the meat and bone meal associated with this investigation and confirmed the ban on specified risk materials from animals over 30 months of age as an appropriate action to take.

Some of the recommendations coming from the Advisory Committee then would be, one, due to the differing perceptions of risk as determined by the subcommittee and in comparison to the Harvard Center for Risk Analysis, the Secretary's Advisory Committee recommends that a representative of Harvard University Center for Risk Analysis review the Subcommittee Report, preferably in direct collaboration with members of the subcommittee. In fact, we have initiated discussions for this type of review and initiating that collaboration between Harvard and the Review Subcommittee.

There was a recommendation from the Advisory Committee to immediately develop and implement an enhanced National Surveillance BSE Program and to increase testing of high-risk animals. And indeed, we are in the process of developing a robust surveillance program and hope to announce details in the near future.

The Advisory Committee recommended a comprehensive system to facilitate identification of pathways for dead and nonambulatory animals into our collection mechanism and then ensure proper and safe disposal of the carcass. And indeed, as part of our surveillance plan we are working with federal and state counterparts to address the issue really on a state-by-state basis with our federal area veterinarian in charge working with his or her counterpart, the state veterinarian, to have an appropriate program in each of the states.

The Advisory Committee supported the Secretary's announcement to move quickly to implement a verifiable national animal identification and tracking system, and in fact the Department is very appreciative of the efforts by many to develop a plan. And the implementation of a national animal identification system remains top priority within the Department.

There was a recommendation to further develop the National Animal Health Laboratory Network and, specifically as it relates to BSE, to approve additional laboratories to conduct rapid screening tests for BSE while maintaining the confirmatory testing at our National Veterinary Services Laboratories.

And certainly the possibility of expanding testing capacity to our network of state diagnostic laboratories is part of our surveillance planning.

The Advisory Committee recommended enhancement to the development and dissemination of a BSE information and education program, and that would be to the media, to the public, and all of the industry stakeholders to ensure that everyone understands the mechanism of BSE transmission, that it's not contagious and that certain safeguards are necessary to control and eliminate the disease.

And again, an overall outreach and education program is a key element of an enhanced surveillance program and is part of our planning.

The Committee encouraged major beef exporting nations to work through the OIE, the World Animal Health Organization, to rationalize trading protocols that apply to countries with a low prevalence of BSE and especially those countries that may have a low prevalence but have adequate safeguards in place. And indeed the United States has been a key player in efforts that are underway -- working very closely with our counterparts in Mexico and Canada as well as around the world -- to promote science-based trade policies that are based on those international standards that you've heard me say before are based on that same science; as opposed to what historically has been an over-reaction from a trade perspective and one based more on emotion and public perception and not on the science.

And finally, the Advisory Committee commended the Food and Drug Administration, the USDA, and officials at the state of Washington for their efforts and swift action to address this first case of BSE found in the United States. They further stressed that it's imperative that all future decisions that the Department makes would be based on the best available science and that all necessary steps be taken to protect the safety of the public as well as the economic viability of animal agriculture in the U.S.

With that, Operator, I think we'll begin to take questions. For those questions that would relate to the avian influenza situation, we have on the telephone Dr. Bob Hillman who is with the Texas Animal Health Commission and of course Dr. Nancy Cox the chief of the Influenza Branch at the CDC. Any feed-related issues on the BSE situation, we have Dr. Steve Sundlof from the Center for Veterinary Medicine.

And I would just remind everyone, if you want to ask a question, you hit *1.

Operator, if we could please take the first question?

OPERATOR: Our first question is from Scott Kilman. Your line is now open. Please state your organization.

SCOTT KILMAN: Yeah, hi. This is Scott Kilman with the Wall Street Journal. I have two questions -- one for Dr. Cox.

Is there any evidence or has there ever been a case where the H5N2 virus has sickened a human anywhere? And then the second question is for Dr. Hillman: Where are the live markets located in Texas, the cities that received the infected birds?

DR. COX: Okay, this is Nancy Cox. In answer to your first question I can say that there are no known human infections with H5N2 viruses either high path or low path.

DR. HILMAN: This is Bob Hillman from Texas Animal Health Commission. The only live bird markets that received birds from the index flock are in Houston. Both of those have been under surveillance and under control for the last several days.

MR. KILMAN: All right. Thank you.

DR. DEHAVEN: Thanks, Bob.

Operator, next question, please? Operator, can we get the next question, please?

OPERATOR: I apologize. Next question is from Randy Fabi. Your line is now open. Please state your organization.

RANDY FABI: Yeah, with Reuters.

In the investigations so far with bird flu, has there been any connection with the outbreak in Asia? Thank you.

DR. DEHAVEN: Randy, this is Ron DeHaven. Absolutely no known outbreak. The Asia virus is an H5N1. This virus in Texas is an H5N2. That alone would be sufficient to say that there would be no epidemiological link between this situation and in Asia. Of course the other viruses that we've been dealing with in the Northeast in Pennsylvania, Delaware, etcetera, has been a completely different virus. So we have no connection, epidemiological link whatsoever at this point, between any of the viruses and the avian influenza activity in the U.S. with the Asian situation.

Next question, Operator?

OPERATOR: Next question's from Dan Goldstein. Please state your organization.

DAN GOLDSTEIN: Yeah, hi. Dan Goldstein with Bloomberg.

Dr. DeHaven, can you explain exactly what the difference between I guess the mortality rates, the level of infectivity, and how fast the disease can spread with a high path virus compared to, say, the low path virus?

DR. DEHAVEN: In terms of the difference in mortality between a low path and a high path -- and this will be a generalization; there's no hard and fast definition -- but typically with a low path virus we've isolated viruses in a situation where there has been no increase in mortality observed and other cases where it has gone as high as 30 or 40 or maybe 50 percent. Typically we would be looking at 10 to 20 percent mortality in, if there is such a thing, the normal low path avian influenza situation.

High-path on the other hand, we can have mortality that would be in the 20 to 30 percent range to nearly 100 percent. Some of these viruses-- while they may all be classed as highly pathogenic, some of them are far more pathogenic than others. This one would suggest that there has been clearly some increased mortality because of the nature of this particular premise, there does not appear to be very good records so we can't pinpoint that. Certainly there has been some increased mortality, but again based on the initial clinical picture we were saying that it looked more like low-path.

A little bit more on the education on how this pathogenicity is determined. Once we have an H5 or an H7 we do both the DNA sequencing as well as the pathogenicity testing where the virus is injected into susceptible chickens. If the DNA sequencing is not consistent with high-path but we get the death loss in the chickens that would qualify for high-path, then we would call it "high-path." If we have a DNA sequence that is highly pathogenic even though the chicken inoculation test may say it's low-path, here again we're going to call it high-path.

So the second test where we have inoculated susceptible chickens at NVSL is just getting underway. It will probably be a week to 10 days before we would have any preliminary results.

In terms of contagiousness and ability to spread, both of them are highly contagious. Both of them are easily spread by movement of poultry and equipment from one farm to another and, hence, the need for good biosecurity on poultry premises even without being faced with one of those viruses. But clearly once in an area where there has been an outbreak the need to control what goes on and off of all poultry premises is absolutely critical.

With that, Operator, next question, please?

OPERATOR: Next question is from Tom Quaff (sp). Please state your organization.

TOM QUAFF (sp): Yes. My name is Tom Quaff. I'm editor of Dairy Herd Management. It's a national magazine for dairy farmers. It's regarding BSE.

Last Wednesday the people who own the slaughter plant that handled the BSE cow in Washington State met with the news media. They said the BSE cow was not a downer cow. They said the cow was walking the day it was slaughtered. Is USDA still standing by its claim that the animal was a downer cow?

DR. DEHAVEN: Well, we're basing our statement that the animal was downer on the fact that there are records from the Food Safety Inspection Service veterinarian who examined this animal before slaughter. He examined her in a recumbent position on the trailer that brought her to the livestock market. Having said that, there is nothing saying that an animal that is down cannot get up. So in fact both accounts could potentially be true.

Recognizing that this is a sensitive issue, that there's been some media interest etcetera, we have, the USDA Office of Inspector General has initiated an investigation. And so I think it's best left at this point not to comment further other than to say it is under investigation. And certainly from my perspective from a disease standpoint the most important thing is that the animal was tested and it was positive, and we have responded aggressively quickly and appropriately since then. And then I think we ought to let the investigation pursue its normal course and determine what actions are necessary based on that at the appropriate time.

Operator, next question?

OPERATOR: Miriam Falco, your line is now open. Please state your organization.

MIRIAM FALCO (sp): Hi, Miriam Falco, CNN.

One of the concerns in Asia -- and I understand there's no connection between the two outbreaks -- was the cleanliness, the way birds were being slaughtered, that there weren't biosafety measures taken. What conditions exist in these plants here stateside? Is the confidence level higher that you've already put 6,600 birds to death? But I mean should more be necessary, that all proper precautions are being taken, thus to reduce the spread?

DR. DEHAVEN: Thank you for that question, and in fact I wouldn't attempt to characterize the biosecurity and sanitary conditions in Asia but would only say that I think the standards in the United States, particularly within our integrated commercial poultry industry, is very good.

If we take this particular situation as an example of the fact that we apparently have caught it early, that we have done surveillance in much of the surrounding area already would suggest that our surveillance system is good and biosecurity on the farm is good as well.

So we have, at least within this country, a commercial industry that is very tuned to the need for good biosecurity. And there will be a real emphasis now in that area obviously because of known infection.

Let me provide Dr. Hillman and Dr. Cox an opportunity to comment on that question as well.

DR. HILLMAN: Ron, thank you. I would also add to what you have said that we have been working with the live bird markets for quite some time on biosecurity measures and also on record keeping relative to the birds they get in, where they come from, how they're sold, etcetera. And I can say that we've had exceptionally good cooperation with the live bird market folks in the areas that these birds have gone to. And I think that also provides some assurance that hopefully we've got this thing in the very early stages of the outbreak and we can contain it very quickly.

DR. DEHAVEN: Dr. Cox, anything to add?

DR. COX: No. I don't have anything to add at this time.

DR. DEHAVEN: Okay, very good. Operator, we'll take two more questions, please. Could we have the first one?

OPERATOR: The next question's from Don Wall (sp). Please state your organization.

DON WALL (WFAA-TV): Hi. I'm Don Wall from WFAA-TV in Dallas.

Dr. Cox, first. How many people are being monitored for exposure by the CDC and/or the Texas Department of Health?

And Dr. Hillman, how many chickens so far have or will be depopulated that you know of in Texas, including the live market chickens in Houston and a possible second hen house on the farm in Gonzales County where the first exposure occurred?

DR. COX: This is Nancy Cox. And as I said before, we'll be working with the state and local health departments to determine how many people have actually been exposed to the infected birds, and we'll be working with them to monitor the situation as the situation progresses.

MR. WALL: Do you have any numbers so far?

DR. COX: No. We will be working with our counterparts to determine how many people potentially have been exposed to these infected birds.

DR. DEHAVEN: Bob, do you want to take the question on the number of birds depopulated?

DR. HILLMAN: Yes, Ron. I will address that. To this point we have depopulated 6,608 broilers. The individual that owned the broilers also in a different facility remote from the location of the broilers does have another flock. That flock is being tested at this point. The only positive birds that we had found had been related to the broiler premises, so where we go from here will be determined by surveillance sampling and identification of additional birds that are either infected or exposed.

MR. WALL: And the number of birds depopulated related to the Houston markets?

DR. HILLMAN: One of the Houston markets did not have live birds on the facility. When we investigated it they did have some product that had been from birds that originated from this premises. Those have been handled. The other market had a few-- they didn't have any chickens but they had a few ducks, and those are being depopulated. I think the number of those is about 20. And they will have been depopulated by now.

DR. DEHAVEN: Thanks, Dr. Hillman.

Operator, last question, please?

OPERATOR: And our last question is from Jerry Hagstrom. Please state your organization.

JERRY HAGSTROM, National Journal of Congress Daily: As far as I can tell from looking at the information on the APHIS website and also from what you said, the committee did not make recommendation to the Secretary on what the International Subcommittee had to say about changes in the feed supply, about you know removing ruminants from all animals and not including mammalian material in the feed. Is that correct that they didn't comment on this?

DR. DEHAVEN: Let me address that initially and then have Dr. Sundlof add to it. I think it was addressed, perhaps tangentially in that one of the areas where there is at least a perception of different levels of risk between the Harvard Center for Risk Analysis and the Subcommittee's Report is in the area of feed and the level of current effectiveness of the feed ban.

And it is in that context then that we, or part of the context that we are then suggesting a follow-up with the Harvard Center for Risk Analysis, looking at the International Review Team Report and recommendations, and in fact collaborating directly with them.

Steve, you want to add to that?

DR. STEVE SUNDLOF: Thank you, Ron. Yeah, that's how I read the report as well. And FDA is also talking with the folks at Harvard to try and reconcile some of the differences that appear to have gone into the Harvard model versus what the expert committee has determined should be the appropriate course.

And so we want to work with the USDA and Harvard in trying to reconcile these differences and then revisit the question about whether or not additional measures need to go into place on restricting feed from certain animals.

Thank you.

DR. DEHAVEN: Very good. Operator, I think that's it. We appreciate again everyone's participation particularly in short order, and I'll pass the baton back to Jim Rogers.


MR. JIM ROGERS: This pretty much wraps up our call for today. Transcripts will be available on our website later this afternoon, and of course if you have questions you can call the Public Affairs Offices at 202-720-4623. Thank you very much, and have a nice day.