American Red Cross Medical Policy on vCJD and BSE

Background In 1995 human cases of a devastating brain disease resembling Creutzfeldt- Jakob Disease (CJD) were found in two British teenagers. In the subsequent medical investigation it was found to be distinct from the classic form of CJD. The variant disease (vCJD) is characterized by "florid" plaques in the brain and is very similar to Kuru and bovine spongiform encephalopathy (BSE). This rapidly progressive, degenerative neurologic disease is silently carried within the body for years before it attacks and destroys the brain, causing rapid deterioration and death usually within a year. The disease process has been described in ancient history but the pathogen itself is a newly recognized agent, a highly resistant infectious protein called a prion. Prion diseases are now known to be a group of uniformly fatal, brain-destroying conditions affecting both humans and animals. Prion transmission has been traced to ingestion in a number of animals. Direct inoculation of infected material has also spread the disease. It is undetectable in the infectious, preclinical state; and sturdy, surviving routine sterilization. The cause of this new vCJD, which has now killed over 100 people in Europe (mostly Great Britain), has now been traced to the consumption of meat and meat products infected with BSE. BSE appeared in the UK in cattle herds during the early 1980s and was speculated to be due to the feeding of parts of sheep infected with scrapie. The route of infection within cows is not well understood. The disease appears in the brain of older cows, presumably following an incubation period elsewhere in the animal's body. Feeding and rendering practices were made more stringent in the UK around 1990, and herds where the infection was present were slaughtered in an attempt to control the disease in cattle. To protect humans from eating beef with high levels of infective particles, only younger cattle are generally used for beef production. The brain and spinal cord-containing parts of the animals are not used for human food or feed for other ruminants as they were in the past. The disease was not found in cattle brain and nervous tissue until they reached three years of age, so cattle were slaughtered for food by 30 months of age. (Some of these younger animals may be infected but the infection has not yet reached their brain.) Hundreds of thousands of cattle have been slaughtered, yet it is estimated that tens of thousands of animals incubating BSE have entered the human food chain. The length of the incubation period for humans is not known but is believed to be five years or longer. The potential magnitude of the epidemic is not known since the prevalence of vCJD in the human population by country is not known. What is clear, however, is that the number of human cases continues to rise. Policy in Response to vCJD Iatrogenic cases of classical CJD have been reported when parts of the brain (dura mater) and pituitary glands from infected humans were used for tissue transplants or injected medicines. In a study of the causes of death in recipients of 197 blood components from donations of individuals who later died of classic CJD, no cases of transfusion-associated Creutzfeldt-Jakob Disease have been recognized. Still, the variant CJD is different from the classic form. The latter, in its incubation period, appears to have substantial involvement of the lymphatic system (Peyers patches, appendix, tonsils, lymph node, spleen). This raises new concerns about transfusion transmission. No test is available to help identify exposed carriers. Some animal-to-animal experiments have suggested the possibility of transmission by blood transfusion under specific laboratory circumstances. As of August 17, 1999, FDA issued guidance which banned blood donations from individuals who had spent cumulative six months or more in the UK during the years when infected beef was thought to be available to market, 1980 to 1996. The United Kingdom includes England, Northern Ireland, Scotland, Wales, Isle of Man, and the Channel Islands. The ARC implemented this policy change in March 2000. Donor loss was estimated to be 2.2% of American blood donors. The American Red Cross conducted a public education campaign to minimize the impact of this donor deferral criterion and allow donors to self-defer. Our observed deferral rate for this exclusion has been 0.13%. Expansion of Existing Policy As the disease in cattle waned in the UK, it began to appear more frequently in the rest of Europe. Contaminated feed that was banned in the UK was exported into the rest of Europe and perhaps elsewhere. Herd testing practices, which had not been uniform, were put into place and infected cattle were found. In 1996 the first case appeared in France and in 2000 human cases (vCJD) were reported in France and Ireland. In response to the spread of BSE and vCJD throughout Europe, the American Red Cross will exclude people who have spent cumulative six months or more in Europe between 1980 and the present from donating blood. The six-month length of exposure in the UK will be reduced to three months, and the years covered will be extended from 1980 to the present. Individuals who have received a blood transfusion in the UK since 1980 will be excluded from donating. When new information becomes available, the policy will be modified accordingly. Implications No cases of BSE or vCJD have been identified in the United States. The U.S. Department of Agriculture and the Food and Drug Administration have instituted controls to minimize the risk of BSE entering our food chain and medicinals. The USDA instituted import bans on British beef and beef products in 1989 and extended the ban to Europe in 1997. It is unclear as to whether this now small-scale human epidemic which has thus far spared our continent will remain small and contained, or will become a major global epidemic in the years ahead. Without a reliable blood test to detect those infected but not yet clinically ill, we have no knowledge of the size of the human reservoir of vCJD that currently exists in any population. Since people travel widely throughout the world that reservoir is not likely to be limited in any one place. Insofar as prions replicate within lymphoid tissue and B-lymphocytes during the symptom-free incubation period (which lasts several years), direct human-to-human transmission of vCJD is theoretically possible from blood transfusions or contaminated surgical instruments. Because of these concerns, the UK has mandated leukoreduction of all blood products and the use of disposable instruments for all tonsillectomies. We believe the expanded exclusion of blood donors is a prudent action in the face of enormous scientific uncertainty, and the threat that vCJD will appear in the United States in the next few years. The ARC deferral policy is estimated to reduce the theoretical risk of vCJD from blood transfusion by 85%. In the context of expanded donor exclusion, which is estimated to involve up to 8% of our donor base, the American Red Cross will substantially increase its efforts to recruit new volunteer donors and encourage greater frequency of donations among existing donors to prevent shortfalls in blood availability. We have committed resources and mobilized expertise to assure that safe blood is available for patients in need. We will inform donors of the new criteria and ensure that our staff are knowledgeable about our policy. Donor deferrals will affect withdrawal of indate products. Plasma not yet pooled would need to be discarded. Lookback and patient notification of exposure are not useful in that we have no blood test or cases from which we could extrapolate patient risk. There is no treatment or lifestyle intervention to recommend. Donor education must not cause public alarm. This will disproportionately impact members of the armed services and their families who have spent time in Europe and the UK. The American Red Cross has been working with the Armed Forces and will assist in any way feasible. Implementation will be in mid-September. June 6, 2001