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RiSk Of Transmissible Spongiform Encepha/opathies to the U.S. Military U.S. forces are continually deploying around the globe. More than 250,000 military personnel) were deployed to more than 130 for eign countries on March 31, 2003 (DOD, 2003), including several countries where bovine spongiform encephalopathy (BSE) had been re- ported and where variant Creutzfel~t-Takob disease (vCTD) subsequently occurred. In addition, U.S. forces are frequently accompanied by their fami- lies when they are deployed on noncombat missions over an extended pe- riod. As a result, U.S. military personnel and their families deployed to countries having reported the occurrence of BSE were at increased risk of exposure to BSE-contaminated food products for several years starting in the early 1980s. Likewise, deployed U.S. military personnel may receive blood transfusions if they are injured in combat or under other circum- stances. These two factors exposure to BSE-contaminated food and expo- sure to BSE-contaminated blood products constitute the focus of this chap- ter. Specifically, we examine how much risk is faced by U.S. forces of acquiring a foodborne BSE infection and under what circumstances that risk would occur. Additionally, we evaluate the risk of acquiring a TSE from a blood transfusion administered to a deployed member of the U.S. forces being treated for trauma or other emergency condition. iThis figure excludes the number of military personnel participating in Operation Iraqi Freedom. 223

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224 ADVANCING PRION SCIENCE RISK OF EXPOSURE TO BEEF PRODUCTS CONTAINING BSE INFECTIVITY Department of Defense Military Food Supply System In assessing the military's risk of exposure to beef products containing BSE infectivity, a brief description of how food is supplied to military per- sonne! is appropriate. All beef products supplied to U.S. forces come from approved suppliers. The forces receive a majority of their food, including beef and beef products, from U.S. producers. Food is prepared and pre- packaged in a variety of ration sets served during training or combat opera- tions. Some meals are served fresh, and regulations dictate that vendors selling food destined for troops be closely inspected and regulated.2 Commanders of U.S. military units have the authority to purchase local food products, including beef. A commander might exercise this authority if his or her troops had been eating prepackaged rations for an extended period of time to offer variety and to maintain high morale. If local beef were purchased in a country where BSE had been reported,3 the troops who consumed it would be at risk of exposure to BSE, although the practice of procuring local beef is the exception rather than the rule. Current policy prohibits the purchase of beef from a country reporting cases of BSE, but it does not prohibit the purchase of beef from other countries, as long as the source is approved by the Department of Defense (DOD) Veterinary Ser- vices. Some beef was purchased from the United Kingdom, Italy, Germany, and Japan before it was recognized as potentially being infected with the BSE agent. DOD Commissary Food System Military personnel, as well as their families, have access to beef prod- ucts through several other outlets as well. The first is the commissary sys- tem. Commissaries are military supermarkets stocked primarily with food products from the United States. U.S. producers generally supply all the beef sold in the commissaries. In some European countries reporting BSE, however, some beef sold in commissaries was procured locally for certain periods of time. From 1980 to 1989, the monthly foreign beef procurement from non-U.S. suppliers averaged 2.5 million pounds. Of this amount, 35 2U.S. Army Regulation AR40-657 (1997); U.S. Navy Regulation NAVSUPINST4355.4F (1997); U.S. Marines Regulation MCOP10110.316 (1997). 3EDITORS' NOTE: After this report was completed, the first U.S. case of BSE was identi- fied in Washington State and was announced to the public on December 23, 2003.

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RISK OF TSEs TO THE U.S. MILITARY 225 percent was from the United Kingdom and 65 percent was from other Eu- ropean countries. Of the product from the United Kingdom, approximately 300,000 pounds was delivered each month to commissary stores north of the Alps (Germany, Belgium, Netherlands, and the United Kingdom) and approximately 575,000 pounds was delivered each month to commissary stores south of the Alps (Italy, Spain, Greece, and Turkey). Supply contracts for 112 stores located on 21 delivery routes were written on a monthly basis. Thus, the source of supplies for a specific store could and did change monthly. Records of specific delivery dates and locations no longer exist. Thus it is impossible to determine which stores received beef from the United Kingdom, but it must be assumed that all stores received some product from that country. These contracts were for carcass beef, which was split into forequarters and hindquarters at the packinghouse and further pro- cessed into cuts for retail sale in the meat market of the commissary store. In 1990 the Beef to Europe Program was initiated for commissary stores north of the Alps. This program, which was congressionally mandated and not related to BSE, entailed the shipment of boxed beef (vacuum-packaged wholesale cuts) of U.S. origin to Europe. During a supply failure, beef was purchased on an emergency basis within Europe. Of these emergency con- tracts, 99 percent were given to German meat packers. All commissary stores within the United Kingdom, with the exception of the commissary in E3zell, Scotland, participated in the Beef to Europe Program. Shipments to the E3zell Commissary and areas south of the Alps con- tinued to be carcass beef from the United Kingdom. These contracts were converted to boxed beef in 1994. After March 1996, all procurement of beef from the United Kingdom ended, and in March 2000, all procurement of European beef stopped. Other Sources of Beef Products Beef products are also sold to members of the U.S. military and their families at post exchanges (PXs), which are located on U.S. military posts and bases. The Army and Air Force Exchange Service (AAFES), which man- ages the exchange system, is not able to provide estimates of the total num- ber of pounds of beef procured in Europe during the same time frames mentioned above. They did, however, use cuts of carcass meat and distribu- tion procedures similar to those described above for the commissary sys- tem. AAFES food service outlets used European beef, and approximately 20 percent of this beef was from the United Kingdom. A third outlet for the purchase of beef by members of the U.S. military and their families is hamburger franchises. Before the reduction of troop strength in Europe, more than 50 hamburger franchises were operating as concessions. These operations used preformed patties from the United King-

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226 ADVANCING PRION SCIENCE dom through 1989. From 1990 to March 2000, either U.S. beef was used, or beef was ground in an AAFES-operated facility in Germany; the latter was a combination of U.S. beef and beef from European countries other than the United Kingdom. Between March 1996 and March 2000, most of the beef originated from European countries without cases of BSE, and some came from the United States. Since March 2000, the beef has been of U.S. or non-European origin. Risk of Exposure to BSE Agent Members of U.S. forces, including their family members, commonly enjoy the local culture and consume locally prepared foods while they are stationed overseas. They purchase food in local markets and dine in local eating establishments. However, the majority of food they consume comes from either the system used to feed troops or the commissary system. The greatest period of risk for exposure to BSE-contaminated beef prod- ucts occurred between 1980 and 1996 in the United Kingdom. For conti- nental Europe, that period of risk was extended beyond 1996. In the early 1980s, the BSE outbreak was not apparent, yet cattle were infected with BSE. Effective controls to prevent further contamination of the food supply were put in place iteratively, first in the United Kingdom and then through- out other European countries. During that period, 4,428,572 military per- sonne! and their family members were potentially exposed to BSE-contami- nated beef products (Table 9-11. U.S. military members and their families living in the United Kingdom and Europe between 1980 and 1996 were at increased risk of exposure to the BSE agent as a result of their consumption of locally procured beef or their consumption of beef in local eating establishments as compared with the risk to their counterparts in the United States. The committee judged, however, the risk of acquiring foodborne-associated vCJD to be relatively small compared with that of the local population due to the lesser con- sumption local beef and the shorter period of exposure. Notification and TABLE 9-1 DOD Active Duty Personnel and Dependents in Europe Period Number of Number of Total Number Active-Duty Personnel Dependents of Individuals 1980-1996 1,932,179 2,496,393 4,428,572 January 1, 2001 215,778 317,231 533,009 SOURCE: Severin (2002).

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RISK OF TSEs TO THE U.S. MILITARY 227 active prospective surveillance are not warranted for these military mem- bers or their families. However, the committee encourages passive moni- toring of the incidence of Creutzfel~t-Takob disease (CTD) among military personnel. Recommendation 9.1: Use existing passive surveillance systems to monitor the incidence of Creutzfel~t-lakob disease and variant Creutzfel~t-lakob disease among individuals receiving medical care from the health systems of the U.S. Department of Defense and the Department of Veterans Affairs. [Priority 314 RISK OF TSE INFECTION FROM BLOOD PRODUCTS Blood transfusions could also place deployed forces at theoretical risk of infection by the agent of BSE or other transmissible spongiform encepha- lopathies (TSEs) (see also Chapters 5 and 71. In a situation in which a de- ployed service member is wounded or otherwise injured and needs a blood transfusion, where does that blood come from and what is the likelihood that it contains the agent of vCTD or another TSE? The DOD Blood Supply System DOD's blood supply is under the management of the Armed Services Blood Program (ASBP). The collection, processing, tracking, storage, and distribution of blood are closely managed (DOD, 19961. The majority of blood used by U.S. forces is collected at 24 blood collection sites: 18 sites in the United States and 6 sites overseas (Sparks, 20021. More than 90 percent of the blood collected at these sites comes from active-duty service members (Sparks, 20021. Some of the military's blood is frozen for longer-term stor- age and use. This stockpile was collected in the early 1990s, before the current blood donation deferral policy was in place (personal communica- tion, LTC R. D. Sylvester, Armed Services Blood Program, November 5, 2002) and would be used only in a major military contingency situation in which fresh blood was unavailable. The U.S. military deploys its own health care system in support of U.S. forces overseas. That system includes medical providers, fixed and mobile hospitals, and medical supplies, including blood. In general, any blood given to a deployed service member would be collected and controlled by ASBP. Thus, the committee concluded that the risk that a service member would 4The committee denotes each recommendation as priority level 1, 2, or 3 based on the criteria and process described in the Introduction.

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228 ADVANCING PRION SCIENCE be transfused blood from a donor having preclinical vCTD would be quite remote. Under some circumstances, blood products are supplied to U.S. facili- ties by the host nation. Examples of such blood products are platelets, which have a very short shelf life, and products whose supplies are exhausted or unavailable. Additionally, U.S. forces deployed overseas use local emergency rooms or hospitals when medical care is not available from the DOD health care system. Should a U.S. service member have an injury serious enough to warrant a blood transfusion from a local hospital in a country reporting BSE, there would be a theoretical risk of exposure to the vCTD agent in the blood, but those situations are uncommon. DOD Blood Donation Deferral Policies Although the risk of a member of the deployed armed forces acquiring a TSE infection from a blood transfusion is presumed to be very low, indi- viduals who were deployed to Europe during the period of risk are not able to donate blood, according to DOD policy (Sparks, 20021. The Food and Drug Administration (FDA) and the American Red Cross have similar blood donation deferral policies (see Table 9-21. This policy results in the deferral of 18 percent of DOD donors and has placed a significant burden on DOD's ability to maintain its blood supply. However, special recruiters at blood donor sites have increased collections by 9 percent, helping to offset these losses (Sparks, 20021. If an antemortem blood test were available and sensi- tive enough to detect prions in blood, it might be possible to return to the blood donor pool more than 4 million donors whose DOD service in Eu- rope precludes them from donating blood, as well as half a million deferred civilians (5 percent of the national blood donor pool) (Sparks, 20021. SUMMARY OF OVERALL RISK This chapter summarized the risk to deployed U.S. forces of acquiring a TSE as the result of eating a food product or receiving a blood product containing TSE infectivity. Both risks are deemed small. Nevertheless, the level of risk is unknown, so the precaution of deferring individuals who were potentially exposed to BSE-contaminated meat from donating blood is justified. Research clarifying the infectious potential of blood products as a vehicle for transmitting prions would help immensely in addressing this issue.

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RISK OF TSEs TO THE U.S. MILITARY TABLE 9-2 Comparison of Deferral Policies 229 Assistant Secretary of Defense for Health Affairs (DOD) U.S. Food and Drug Administration American Red Cross United Kingdom (UK) Cumulative time 2 3 months 1980-1996 Transfusion in UK 1980-present Cumulative time 2 3 months 1980-1996 Transfusion in UK 1980-present Europe and otI7er countries associated witI7 BSE by USDA Cumulative time 2 3 months 1980-presenta Transfusion in UK 1980-present Europe 1980-present Europe 1980-present All of Europe, regardless of cumulative time cumulative time 2 5 years USDA rating, cumulative time 2 5 years (applies to (applies to DOD after 1997) 2 6 months 1980-present DOD after 1997) DOD stationed in DOD stationed in Europe Europe 1980-1996 from 1980-1990 (north of cumulative time the Alps) cumulative 2 6 months. time 2 6 months. DOD stationed in Europe from 1980-1996 (south of the Alps) cumulative time 2 6 months. aThe American Red Cross recently changed its policy to defer donations of blood from individuals who spent 3 months or more living in the United Kingdom between 1980 and 1996 (personal communication, R. Dodd, The American Red Cross Holland Laboratory, June 27, 2003). NOTE: USDA = U.S. Department of Agriculture. SOURCE: Sparks (2002). REFERENCES DOD (U.S. Department of Defense). 1996. Department of Defense Instruction 6480.4. Wash- ington, DC: Armed Services Blood Program, DOD. DOD.2003. Active duty military personnel strengths by regional area and by country (309A). Washington, DC: Statistical Information Analysis Division Personnel, Directorate for Information Operations and Reports, Washington Headquarters Services, Department of Defense. [Online]. Available: http://www.dior.whs.mil/mmid/M05/hstO303.pdf.html [ac- cessed November 21, 2003]. Severin SR. 2002. Protecting tile DoD Food Supply from TSEs. Presentation to the IOM Committee on Transmissible Spongiform Encephalopathies: Assessment of Relevant Sci- ence, Meeting I. Washington, DC. Sparks RA. 2002. Armed Services Blood Program vCJD Update. Presentation to the IOM Committee on Transmissible Spongiform Encephalopathies: Assessment of Relevant Sci- ence, Meeting I. Washington, DC.

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RISK OF TSEs TO THE U.S. MILITARY TABLE 9-2 Comparison of Deferral Policies 229 Assistant Secretary of Defense for Health Affairs (DOD) U.S. Food and Drug Administration American Red Cross United Kingdom (UK) Cumulative time 2 3 months 1980-1996 Transfusion in UK 1980-present Cumulative time 2 3 months 1980-1996 Transfusion in UK 1980-present Europe and otI7er countries associated witI7 BSE by USDA Cumulative time 2 3 months 1980-presenta Transfusion in UK 1980-present Europe 1980-present Europe 1980-present All of Europe, regardless of cumulative time cumulative time 2 5 years USDA rating, cumulative time 2 5 years (applies to (applies to DOD after 1997) 2 6 months 1980-present DOD after 1997) DOD stationed in DOD stationed in Europe Europe 1980-1996 from 1980-1990 (north of cumulative time the Alps) cumulative 2 6 months. time 2 6 months. DOD stationed in Europe from 1980-1996 (south of the Alps) cumulative time 2 6 months. aThe American Red Cross recently changed its policy to defer donations of blood from individuals who spent 3 months or more living in the United Kingdom between 1980 and 1996 (personal communication, R. Dodd, The American Red Cross Holland Laboratory, June 27, 2003). NOTE: USDA = U.S. Department of Agriculture. SOURCE: Sparks (2002). REFERENCES DOD (U.S. Department of Defense). 1996. Department of Defense Instruction 6480.4. Wash- ington, DC: Armed Services Blood Program, DOD. DOD.2003. Active duty military personnel strengths by regional area and by country (309A). Washington, DC: Statistical Information Analysis Division Personnel, Directorate for Information Operations and Reports, Washington Headquarters Services, Department of Defense. [Online]. Available: http://www.dior.whs.mil/mmid/M05/hstO303.pdf.html [ac- cessed November 21, 2003]. Severin SR. 2002. Protecting tile DoD Food Supply from TSEs. Presentation to the IOM Committee on Transmissible Spongiform Encephalopathies: Assessment of Relevant Sci- ence, Meeting I. Washington, DC. Sparks RA. 2002. Armed Services Blood Program vCJD Update. Presentation to the IOM Committee on Transmissible Spongiform Encephalopathies: Assessment of Relevant Sci- ence, Meeting I. Washington, DC.