News & Events
Ruminant-to-ruminant Feed Ban and the Potential Transmission of Spongiform Encephalopathies to Humans
Michael A. Friedman, M.D.
Deputy Commissioner for Operations
Food and Drug Administration
Public Health Service
Department of Health and Human Services
Subcommittee on Human Resources
Subcommittee on Intergovernmental Relations
Committee on Government Reform and Oversight
January 29, 1997
Mr. Chairman, Members of the Committee, thank you for the opportunity to participate in today's hearing on the proposed rule on the ruminant to ruminant feed ban and the potential transmission of spongiform encephalopathies to humans. My name is Dr. Michael Friedman and I am the Deputy Commissioner for Operations at the Food and Drug Administration (FDA).
FDA is the nation's oldest consumer protection agency, responsible for the safety and effectiveness of over $1 trillion worth of products and commodities. We have been protecting consumers against an ever-growing number of public health risks for over nine decades, and we have not done it by standing still. FDA constantly is being presented with new questions, for which we are committed to seeking and finding answers, while applying current statutes, state of the art science, and knowledge gained from our experiences in responding to previous public health risks.
FDA's responsibilities encompass drugs for use in people and animals, human biological products, medical devices, food, dietary supplements, cosmetics, and animal feeds. Each of these product groups has been considered with respect to the potential for the transmissible spongiform encephalopathies (TSEs) in humans or animals. As you may know, TSEs are a group of transmissible, slowly progressive, degenerative diseases of the central nervous systems of humans and several species of animals. This family of diseases is characterized by a long incubation period, a relatively short clinical course of neurological signs, and 100 percent mortality. Examples of TSEs are scrapie in sheep and goats, bovine spongiform encephalopathy in cattle, transmissible mink encephalopathy, chronic wasting disease of deer and elk, and Creutzfeldt-Jakob Disease (CJD) and kuru in humans.
FDA has been involved actively in national and international efforts focused on better understanding TSEs. FDA has collaborated extensively with its sister Public Health Service Agencies, the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH), and with the United States Department of Agriculture (USDA), as well as with affected industries and consumer groups. FDA has formed an intra-agency working group composed of myself and experts from each FDA Center to consider transmissible spongiform encephalopathies and their impact on FDA-regulated products. A CJD Advisory Committee, composed of outside experts, including academic and government representatives; consumer groups, including the National Hemophiliac Foundation; and industry groups, also was formed in 1995, and was rechartered in June 1996 for two additional years as the TSE Advisory Committee.
BOVINE SPONGIFORM ENCEPHALOPATHY (BSE)
Bovine spongiform encephalopathy (BSE), also referred to as ?mad cow disease,? is thought to be a transmissible, slowly progressive, degenerative disease of the central nervous system of cattle, and is similar to scrapie in sheep. BSE has a prolonged incubation period in cattle (three to eight years) following oral exposure and, as with all TSEs, once symptoms appear, BSE invariably is fatal. There is no known treatment or cure. That said, we emphasize that BSE has not been detected in cattle in the U.S., and since 1989, no cattle have been imported from BSE countries as designated by the USDA.
Since BSE was first diagnosed in the United Kingdom (UK) in November 1986, more than 165,000 cattle from almost 33,000 herds have been diagnosed with the disease. BSE now has been reported in native cattle in France, Switzerland, Portugal, the Republic of Ireland, and Northern Ireland. The epidemic in the UK peaked in January 1993 at nearly 1,000 new cases per week; currently fewer than 200 suspected cases are diagnosed every week. The disease has had a devastating impact on the cattle and beef industry in the UK where hundreds of thousands of suspect cattle have been killed and incinerated to prevent further spread of the disease.
Epidemiological studies, including computer simulation of the epidemic in the UK, suggest that feeding cattle rendered meat and bone meal from animals infected with some TSE agent was the vehicle for the spread of the disease. The practice of adding meat and bone meal to animal feed has become a common way for producers to supplement their animals? protein and other dietary needs. Possible hypotheses as to the original UK source of the TSE agent are: 1) that it was a modified form of scrapie transmitted via rendered by-products of sheep, or 2) that it was a cattle-adapted strain of a scrapie-like agent, also spread via feed. Both theories are consistent with the epidemiological findings. Of particular importance, recent research in the UK suggests that the BSE agent is resistant to the rendering processes used in that country. This research further supports the epidemiological evidence that the disease has been spread through rendered meat and bone meal added to cattle feed. Scientists also have theorized, however, that BSE could occur spontaneously in cattle, though presumably at a very low rate.
Possible Link Between BSE and CJD
Scientists also have theorized about the impact of BSE on human health and its possible link to CJD. CJD is a slow degenerative human disease of the central nervous system characterized by motor dysfunction, progressive dementia, and vacuolar degeneration of the brain. The incidence of CJD in the U.S. is similar to the incidence in the rest of the world. Sporadic cases of CJD occur world-wide at a rate of one case per million population per year.
On March 20, 1996, the British Government announced a possible link between BSE and ten cases of a new type of CJD in humans. These recent cases appear to represent a new variant of CJD (nv-CJD) that seems to be unique. At a World Health Organization (WHO) consultation in April 1996, a group of international experts concluded that there is no definite link between BSE and this small group of people with nv-CJD, but epidemiological evidence suggests exposure to BSE before the UK specified tissue ban in 1989 may be the most likely explanation. To date, scientists have identified the distinctive nv-CJD brain pathology in 15 people with CJD in BSE countries (14 in the UK, 1 in France). In October 1996, Dr. John Collinge, one of the foremost British authorities on CJD, and his colleagues published the results of their research on various strains of the agents believed to transmit BSE. The results suggest that the agent found in nv-CJD resembles the BSE agent rather than the sporadic CJD agent.
As stated, BSE has not been detected in cattle in the U.S., and since 1989, no cattle have been imported from BSE countries as designated by USDA. Nevertheless, the possible link between nv-CJD and BSE, and new information about the origin and etiology of the BSE agent have prompted the public, the U.S. Government and affected industries to view this disease very seriously. As a result, several important measures have been undertaken to further reduce the remote risk of BSE occurring in the U.S. It should be stressed, however, that there is no established scientific link between BSE and CJD in humans.
Proposed Rule: Ruminant and Mink to Ruminant Feed Ban
One critical measure is the issuance by FDA of a Notice of Proposed Rule Making (NPRM) to prohibit the use of nearly all tissues from ruminants -- animals such as cows, sheep, and goats -- in feed intended for ruminants. Mink tissue also would be prohibited from such feeds, because of known cases of TSE in mink raised in the U.S. The prohibition on feed ingredients proposed in the NPRM is intended to prevent the spread of BSE in cattle in the unlikely event that the disease should ever occur in this country, and to further minimize any risk that might be posed to humans. The NPRM was published in the Federal Register on January 3, 1997, after FDA completed an in-depth review of the 660 comments it received last year in response to its advance notice of proposed rulemaking related to the feed ban. These comments covered many of the scientific and economic issues addressed in the NPRM. FDA's proposal to ban the use ruminant and mink proteins in ruminant feed follows a voluntary industry moratorium on similar feeding practices instituted in March 1996 by national livestock organizations and professional animal health groups and endorsed by FDA, CDC, NIH, and the USDA. The finalization of the proposal will add another level of safeguards to protect the U.S. against the remote potential risk from TSEs.
Moreover, FDA's proposed regulation is supported by last year's WHO recommendations for countries in which no BSE has been diagnosed.
The NPRM provides that animal protein derived from ruminant and mink tissues are not generally recognized as safe (GRAS) for use in ruminant feed and is a food additive subject to section 409 of the Federal Food, Drug, and Cosmetic (FDC) Act. The determination of food additive status for this substance (protein derived from ruminant and mink tissues) will help to ensure that it will not be marketed in the U.S. until such time as FDA determines it to be safe. The NPRM proposes to exempt from the ruminant protein feed ban three tissue types that have shown no signs of potential infectivity. These exceptions include bovine blood, ruminant-derived milk, and gelatin. A second component of the rule provides for a system of processes and controls, including record keeping and labeling, that is necessary to ensure the proposed rule will achieve its intended purpose. Based on the overwhelming evidence we have on transmissibility, if for some reason a case of BSE were to occur in the U.S., and it is important to reemphasize that not even one case of BSE has ever been found here, the steps being proposed in the NPRM would confine it to the individual animal and greatly decrease the potential risk to other animals and humans.
The preamble to FDA's proposed rule points out that FDA is considering alternatives to the proposed ruminant and mink protein to ruminant prohibition and that it also is seeking comments on those alternatives, which include a(n): (1) Adult sheep and goat specified offal to ruminant prohibition; (2) Prohibition to ruminants of all materials from U.S. species which have been diagnosed with TSEs (sheep, goats, mink, deer, and elk); (3) Partial ruminant to ruminant prohibition; (4) Mammal to ruminant prohibition; (5) No regulatory action; and, (6) Other alternative approaches that meet FDA's regulatory objective.
Although BSE does not exist in the U.S., we believe that the preventive approach FDA is taking in the NPRM is justified by what we now know about this disease and how it is caused and spread. As noted above, epidemiological evidence corroborates the theories that the origin of BSE was caused by the feeding to cattle of meat and bone meal either containing the scrapie agent from rendered by-products of sheep, or a cattle-adapted strain of a scrapie-like agent from rendered by-products of cattle. Current U.S. rendering techniques would decrease, but probably not totally eliminate the BSE agent. Since sheep scrapie and other animal-borne TSEs already are known to exist in the U.S., the epidemiological evidence indicates that BSE could possibly develop and be spread here under unrestricted feeding practices. Moreover, the risk that BSE-infected cattle or feed could be imported inadvertently from BSE infected countries, or that BSE could occur spontaneously further supports the preventive strategy proposed in the NPRM. The strategy provided in the NPRM also is supported by the steady decline in the number of cases of BSE in the UK after they established similar restrictions on ruminant feeding practices.
Comments are being solicited by FDA on all aspects of the NPRM, including the scope of the ban and the list of exempted tissue types. A 45 day public comment period expires on February 18, 1997. To facilitate notice and comment on the NPRM, in addition to providing the proposed rule to the CDC, NIH and the USDA, FDA provided a copy of the proposed rule to the group of international experts interested in BSE. The document was delivered to heads of foreign public and animal health organizations and to appropriate officials of our major animal products trading countries. During February, FDA will hold two open public forums to discuss the notice of proposed rule making to prohibit the use of rendered ruminant and mink protein products in ruminant feeds. Comments may be submitted to the Dockets Management Branch, Food and Drug Administration, 12320 Parklawn Drive, Room 1-23, Rockville MD 20857. These comments will be reviewed by the Food and Drug Administration and will be used in preparing final regulations.
FDA recognizes that American consumers look to us to assure the safety of the U.S. food supply. We believe that the strong preventive strategy provided in the NPRM is supported by the best available science on BSE and that this approach significantly reduces risk to animal health and any perceived risk to human health. As the scientific knowledge about BSE, and all TSEs, increases -- and the science in this area is growing rapidly -- FDA will continue to review this new evidence and steer a course that maintains high standards for food safety in this country.
CJD AND PROTECTION OF THE BLOOD SUPPLY
The history of TSE raises questions regarding the transmissibility of CJD through human tissue. While there are no recorded cases of CJD transmission in humans through blood, there is a theoretical possibility for transmission and FDA has taken aggressive actions to significantly mitigate that potential risk.
The blood supply plays a critical role in the American health care system. While the U.S. has one of the safest blood supplies in the world, it is a formidable task to keep it so. Each year, approximately 12 million units of blood are drawn from volunteer donors for use by more than 3.5 million Americans. Much of this blood, and an additional 12 million units of plasma, is processed into further products, referred to as derivatives, such as immune globulin, used to prevent infections, and clotting factors, such as antihemophilic factor, used to treat bleeding disorders.
Because blood donors may harbor undetectable or undetected communicable disease, blood can transmit disease. Because of this risk, and the fact that millions of Americans depend on blood and blood products, efforts to ensure the safety of the blood supply are a high priority for FDA. One of the challenges such efforts entails is application of current, but incomplete and emerging scientific knowledge, in the decisions about how best to protect public health. CJD presents such challenges.
Background/History of CJD
CJD is a rare but invariably fatal, degenerative neurological disease believed to be associated with a transmissible agent. Cases arise spontaneously at low frequency for unknown reasons; perhaps acquired by external exposure to infectious material; or may arise spontaneously at higher frequency in persons with certain genetic mutations. CJD affects approximately one person to two person per million per year worldwide. From 1979 through 1994, CJD was recorded as a cause of death in 3,642 deaths in the U.S.; representing a stable incidence. (CDC Dispatches, Emerging Infectious Diseases, Vol. 2, No. 4, October-December 1996). The clinical latency of CJD can exceed thirty years, although the incubation period is shorter for the known iatrogenic cases.
The nature of the transmissible agent for CJD is not established, but seems to be highly resistant to the current methods of viral inactivation employed with plasma derivatives. The disposition of the agent during fractionation of various plasma derivatives is not presently known.
Between 1983 and 1997, approximately 300 million units of blood and plasma were donated. From 34 reports received (with some reports containing information on more than one donor), 37 donors were either subsequently diagnosed with CJD or deferred based on concerns with CJD. Of the 37 blood/plasma donors, 25 were reported as subsequently diagnosed with CJD; four had a family member who was diagnosed with CJD; four had received Human Pituitary-Derived Growth Hormone (HGH); and, four had received a dura matter transplant.
The available basic scientific and applied epidemiological data provide no evidence of transmission of CJD via blood transfusion in humans. Moreover, transmission by intravenous infusion of whole blood from CJD patients has not been demonstrated in subhuman primates. The disease, however, has been verified to be transmitted between humans by transplantation of corneas and cadaver dura mater grafts from affected individuals, by use of contaminated EEG electrodes, by certain neurological procedures and by injections of HGH. (CDC Dispatches, Emerging Infectious Diseases, Vol. 2, No. 4, October-December 1996). (It should be noted that HGH is no longer used having been replaced by a recombinant-DNA derived alternative product.) In addition, the disease has been transmitted to rodents in laboratory experiments by injecting the buffy coat component of blood from an affected patient into the rodent brain. Although CJD has occurred in transfused patients, we stress that there has not been a documented case of CJD being transmitted through a blood transfusion. Moreover, there has not been an identified case of hemophiliac death from CJD.
We know that despite our best efforts blood and blood products will never be totally risk free, but we continue to work to achieve optimal safety and availability. While our current knowledge of blood-borne diseases has improved significantly over the past 10-15 years, current scientific knowledge is still incomplete. For example, there is currently no serum test capable of detecting CJD infection.
The fact that there are no documented cases of blood or blood product transmission of CJD in humans does not end the inquiries into the disease nor does it mean that FDA and other agencies and research entities can be complacent. Basic and applied research into the infectious processes of CJD continue to serve as the catalyst for the evolution of FDA policy. We cannot let the absence of scientific information paralyze us.
FDA Regulatory Response
The development of FDA regulatory policy with respect to blood products that could possibly carry a risk of the disease CJD has been vigorous and is ongoing. As clinical and epidemiological knowledge of CJD has increased, FDA has responded aggressively by reviewing and modifying its policy. Throughout this process, FDA has worked closely with both CDC and NIH, among others, in determining the most appropriate regulatory course of action. Extensive public discussion with all segments of those affected - recipients of products, medical professionals, academicians and industry -- has been conducted throughout FDA deliberations.
FDA Actions Related to Blood and Blood Products
FDA involvement in addressing the possible impact of CJD on the nations's blood supply began with the early awareness of possible transmission. On November 25, 1987, FDA issued a ?Memorandum to All Blood Establishments? entitled ?Deferral of Donors Who Have Received Human Pituitary-Derived Growth Hormone.? This document recommended that all persons who received HGH be barred permanently from donating blood or plasma.
For the period 1983-1992, there were only four reported blood donors who had a confirmed diagnosis of CJD reported post-donation. In response, the blood and plasma product manufacturers initiated a voluntary withdrawal of in-date products that had been prepared from donations from these individuals. In December 1993 FDA expanded its position and issued recommendations for more complete reporting of ?post donation information? related to safety.
Partly as a result of these FDA policy recommendations, in late 1994 and early 1995 FDA began receiving additional reports of CJD affected individuals who had donated blood and plasma. At FDA's request, the manufacturers placed in-date, licensed, injectable derivatives (of blood and plasma), as well as intermediates (those products used in further processing), into quarantine awaiting development of FDA recommendations on the use of implicated material.
At the Blood Products Advisory Committee (BPAC) FDA presented data regarding the biology of CJD and case histories of CJD-related donor deferrals and product withdrawals on December 15, 1994. In March 1995, BPAC was again updated on CJD. BPAC was presented with the available scientific information and options for action. BPAC was unable to reach consensus decisions on all of the issues related to product disposition and recipient notification.
FDA, in an effort to further develop its policy on CJD, and because of the outstanding issues that required additional public discussion and consideration, formed a Special Advisory Committee on Creutzfeldt-Jakob Disease and presented information to it on June 22, 1995. The Special Advisory Committee agreed that:
- there was no scientific evidence that CJD is transmitted by transfusion of blood products or by administration of plasma derivatives;
- implicated blood components should be withdrawn;
- implicated plasma derivatives should be withdrawn; and
- if implicated blood components and/or plasma derivatives are to be released for transfusion, these products should bear special warning labels.
Within two months, after considering these deliberations and extensive internal discussion, FDA issued an interim policy in a memorandum dated August 8, 1995, regarding blood products and plasma derivatives. This further broadened its guidance on donor exclusions for CJD risk and called for withdrawal of implicated blood products. A provision was made for release of affected products in case of a documented shortage provided that the products carried a special label.
In an effort to further expand the knowledge of CJD, FDA and NIH's National Heart, Lung, and Blood Institute held a CJD Workshop on Design of Experimental Studies of Transmission of CJD. The FDA also held many discussions at BPAC on product warning labels.
To avoid the disposal of safe and effective products while protecting public health and safety, FDA consulted extensively with experts in the field of TSEs on the familial nature of some CJD cases and appropriate use of genetic testing to clarify risk. The Transmissible Spongiform Encephalopathies Advisory Committee (TSEAC) (formally known as the Special Advisory Committee on Creutzfeldt-Jakob Disease) met a second time on July 2, 1996, and discussed refinements to the August 1995 policy. These included the option of reentering deferred donors based on genetic testing results and the disposition of plasma derivatives prepared from product collected from donors with only a single family member diagnosed with CJD. Also, in November 1996, FDA, in cooperation with others, held two public meetings/workshops. Notification procedures to be utilized for implicated products were considered.
FDA revised its recommendations for CJD in a memorandum to manufacturers on December 11, 1996, based on opinions of the advisory committees, public discussion, FDA internal deliberations and discussions with other agencies. The December 11 memorandum updated and superseded the FDA memoranda of August 8, 1995 and November 25, 1987.
FDA, in its December 11 Memorandum, reiterated that the assessment of CJD risk in the donor is a critical responsibility of the blood establishments. In particular, FDA emphasized that family history of CJD requires careful investigation. FDA has recommended that a family history of CJD should be confirmed by a physician and documented on the basis of currently accepted diagnostic procedures. Also, familial risk, in the context of a donor, applies only to blood relatives of non-iatrogenic cases.
The cautious approach the FDA has taken on CJD related to blood products also affects other products. There are estimated to be over 500 products which use plasma products/derivatives either in manufacturing or formulation. Plasma for manufacturing comes from approximately 25 million donations of blood and plasma derived from about 10 million blood and plasma donors per year. Over a ten year period, 1984-1993, plasma fractionation capacity worldwide increased 61 percent. (Robert, Journal of the American Blood Resources Association, at 75, Vol. 4, No. 3 1995).
There is ongoing discussion being conducted by FDA and others concerning the level of risk of CJD transmission in plasma derivatives and blood components. Experiments to quantify this risk are being undertaken by the government and the blood industry. However, it is likely to take several years before conclusive results are obtained. Most scientists believe that any risk from plasma derivatives must be significantly less than from whole blood components.
Despite this inability to more precisely quantify the nature of the risk, as a precaution, FDA has recommended that Source Plasma and plasma derivatives, prepared from donors who are at increased risk for developing CJD, should be quarantined and destroyed. FDA has made an exception from this quarantine for the plasma derivatives, i.e., albumin, immune globulin, etc. (licensed, injectable products), prepared from pools which contain products collected from a donor with only one known family member with CJD. This exception is made because the probability that the case represents familial CJD is low.
FDA has not recommended the quarantine of blood products intended for further research or manufacturing into non-injectable products. FDA has recommended, however, that such products should be labeled with the following statements: 1) ?Biohazard?; 2) ?Collected from a donor determined to be at risk for CJD?; and, 3) ?For laboratory research use only?, or "Intended only for further manufacture into non-injectable products".
In the circumstances of a donor with CJD or at increased risk for CJD, consignee notification is recommended to permit recipient tracing and notification as deemed medically appropriate. Given the limited current knowledge about CJD as it relates to blood safety, FDA has made only a few general recommendations about ?lookback? notification. In the event that a donor gives a history of only one known family member with CJD, FDA does not recommend notification of consignees of plasma derivatives or expired blood components.
FDA policy on protection of the blood supply from the remote possibility of CJD transmission has been developed as knowledge and data has evolved. The recommendations for donor deferral, product disposition, and recipient notification have been developed based on a consideration of risk in the donor, risk from the product, and the potential impact on blood product availability. Given the significant size of the population using these products, it is appropriate for FDA to consider the impact of withdrawal from distribution of plasma products in its risk benefit analysis from the perspective of both the effect on the supply of products and the benefit to potential recipients of the products. In its decisions, FDA attempts to balance the need for the products and the risk of using the products.
FDA Decision Making: Case Study
The application of FDA policy in situations involving CJD is evidenced by a recent case. FDA was notified that the certain lots of anti-hemophilic products were manufactured using an ingredient, which had been prepared from pooled plasma, containing a unit from a blood donor who later died of CJD. These particular anti-hemophilic products had not been released (for distribution) nor approved for release by FDA at the time of the notification to FDA.
In this case, FDA was faced with evaluating the potential risk of CJD in the final products; determining whether FDA should approve release of the lots; and, if released was approved, should any type of notification be provided.
FDA requested a risk assessment from the company which concluded that the risk of CJD in the product was negligible. This risk assessment was reviewed internally and independent risk assessments were obtained from CDC, NIH and Johns Hopkins University. All agreed that the risk, if any, was likely to be remote and considered ?vanishingly small? in one analysis. An assessment also was made of the impact on the supply of purified factor VIII available for recipients if the product was not released. The conclusion, based on the scientific analysis and all available, relevant data, was that there was a remote risk of CJD and the products were suitable for release. FDA requested, however, that the situation be conveyed to the affected community -- the hemophilia organizations. The company informed the hemophilia groups. The groups released information on the situation in a community newsletter and other sources.
FDA continues to develop its policy and evaluate the safety of products that have had exposure to an implicated plasma derivative (usually transferrin or albumin) during manufacturing or formulation as new data and information are available.
Adequacy of FDA Response
Although FDA's regulatory response to CJD was initiated long before 1995, the recommendations and comments of the Institute of Medicine (IOM) in its 1995 report could be considered as a framework for evaluating FDA's actions concerning the possible CJD transmission in the blood supply. In its 1995 report HIV and the Blood Supply: An Analysis of Crisis Decisionmaking, the IOM concluded that FDA had ?missed opportunities? for action in addressing the potential for HIV infection in the blood supply and had chosen ?the least aggressive option that was justifiable.? The report acknowledged that previous decisions were made ?in the context of great uncertainty? given the science. When ?knowledge is imprecise and incomplete,? however, IOM recommended that there should be ?a more systematic approach to blood safety regulation when their [sic] is uncertainty and danger to the public.?
The IOM made several recommendations directed specifically at FDA which mirror FDA's actions in developing responses to possible CJD transmission through the blood supply.
Recommendation 6 of the IOM report stated:
Where uncertainties or countervailing public health concerns preclude completely eliminating potential risks, the FDA should encourage, and where necessary require, the blood industry to implement partial solutions that have little risk of causing harm.
Recommendation 7 of the IOM report stated:
The FDA should periodically review important decisions that it made when it was uncertain about the value of key decision variables.
FDA has undertaken to incorporate these recommendations into its decision making and oversight of the nation's blood supply. The discussion of FDA's actions taken in response to the concerns raised by possible CJD transmission illustrate that FDA has benefited from past lessons and has responded to the challenge of dealing with uncertain risks that could impact the safety and availability of blood and plasma products.
This Committee also made recommendations in its report Protecting the Nation's Blood Supply From Infectious Agents: The Need For New Standards To Meet New Threats (House Report 104-746, August 2, 1996). In response to the Committee's concerns, FDA has provided enhanced public access concerning recalls and withdrawals of blood and blood products; increasing public input in the discussion regarding policy development on withdrawals and notification of plasma products; and, continuing research into the risk factors associated with pool size of donors.
FDA has made information concerning recalls and withdrawals widely available to interested and affected parties. A voice information system with toll free lines has been set up with information on fractionated product recall and market withdrawal information. A fax information system has been put into place allowing ?fax-on-demand.? The FDA Home Page contains the recall and withdrawal information and an automated e-mail system has been established to distribute information to those persons desiring information not only on recalls and withdrawals but all blood related public documents.
FDA continually strives to make the food and blood supply safer. We will continue to evaluate new studies, scientific and epidemiological data on TSEs and apply that knowledge to FDA policy. We look forward to working with the Committee on these issues.