Variant Creutzfeldt-Jakob disease (vCJD) is a human prion disease caused by infection with the agent of bovine spongiform encephalopathy. After the recognition of vCJD in the UK in 1996, many nations implemented policies intended to reduce the hypothetical risk of transfusion transmission of vCJD. This was despite the fact that no cases of transfusion transmission had yet been identified. In December 2003, however, the first case of vCJD in a recipient of blood from a vCJD-infected donor was announced. The aim of this study is to ascertain and compare the factors that influenced the motivation for and the design of regulations to prevent transfusion transmission of vCJD in the UK and US prior to the recognition of this case.
Methods and Findings
A document search was conducted to identify US and UK governmental policy statements and guidance, transcripts (or minutes when transcripts were not available) of scientific advisory committee meetings, research articles, and editorials published in medical and scientific journals on the topic of vCJD and blood transfusion transmission between March 1996 and December 2003. In addition, 40 interviews were conducted with individuals familiar with the decision-making process and/or the science involved. All documents and transcripts were coded and analyzed according to the methods and principles of grounded theory. Data showed that while resulting policies were based on the available science, social and historical factors played a major role in the motivation for and the design of regulations to protect against transfusion transmission of vCJD. First, recent experience with and collective guilt resulting from the transfusion-transmitted epidemics of HIV/AIDS in both countries served as a major, historically specific impetus for such policies. This history was brought to bear both by hemophilia activists and those charged with regulating blood products in the US and UK. Second, local specificities, such as the recall of blood products for possible vCJD contamination in the UK, contributed to a greater sense of urgency and a speedier implementation of regulations in that country. Third, while the results of scientific studies played a prominent role in the construction of regulations in both nations, this role was shaped by existing social and professional networks. In the UK, early focus on a European study implicating B-lymphocytes as the carrier of prion infectivity in blood led to the introduction of a policy that requires universal leukoreduction of blood components. In the US, early focus on an American study highlighting the ability of plasma to serve as a reservoir of prion infectivity led the FDA and its advisory panel to eschew similar measures.
The results of this study yield three important theoretical insights that pertain to the global management of emerging infectious diseases. First, because the perception and management of disease may be shaped by previous experience with disease, especially catastrophic experience, there is always the possibility for over-management of some possible routes of transmission and relative neglect of others. Second, local specificities within a given nation may influence the temporality of decision making, which in turn may influence the choice of disease management policies. Third, a preference for science-based risk management among nations will not necessarily lead to homogeneous policies. This is because the exposure to and interpretation of scientific results depends on the existing social and professional networks within a given nation. Together, these theoretical insights provide a framework for analyzing and anticipating potential conflicts in the international management of emerging infectious diseases. In addition, this study illustrates the utility of qualitative methods in investigating research questions that are difficult to assess through quantitative means.
A qualitative study of US and UK governmental policy statements on the topic of vCJD and blood transfusion transmission identified factors responsible for differences in the policies adopted.
In 1996 in the UK, a new type of human prion disease was seen for the first time. This is now known as variant Creutzfeldt-Jakob disease (vCJD). Prion diseases are rare brain diseases passed from individual to individual (or between animals) by a particular type of wrongly folded protein, and they are fatal. It was suspected that vCJD had passed to humans from cattle, and that the agent causing vCJD was the same as that causing bovine spongiform encephalopathy (or “mad cow disease”). Shortly after vCJD was recognized, authorities in many countries became concerned about the possibility that it could be transmitted from one person to another through contaminated blood supplies used for transfusion in hospitals. Even though there wasn't any evidence of actual transmission of the disease through blood before December 2003, authorities in the UK, US, and elsewhere set up regulations designed to reduce the chance of that happening. At this early stage in the epidemic, there was little in the way of scientific information about the transmission properties of the disease. Both the UK and US, however, sought to make decisions in a scientific manner. They made use of evidence as it was being produced, often before it had been published. Despite this, the UK and US decided on very different changes to their respective regulations on blood donation. Both countries chose to prevent certain people (who they thought would be at greater risk of having vCJD) from donating blood. In the UK, however, the decision was made to remove white blood cells from donated blood to reduce the risk of transmitting vCJD, while the US decided that such a step was not merited by the evidence.
Why Was This Study Done?
This researcher wanted to understand more clearly why the UK and US ended up with different policies: what role was played by science, and what role was played by non-scientific factors? She hoped that insights from this investigation would also be relevant to similar challenges in the future—for example, as many countries try to work out how to control the threat of avian flu.
What Did the Researcher Do and Find?
The researcher searched for all relevant official government documents from the US and UK, as well as scientific papers, published between the time vCJD was first identified (March 1996) and the first instance of vCJD carried through blood (December 2003). She also interviewed people who knew about vCJD management in the US and UK—for example, members of government agencies and the relevant advisory committees. From the documents and interviews, the researcher picked out and grouped shared ideas. Although these documents and interviews suggested that policy making was rooted in scientific evidence, many non-scientific factors were also important. The researcher found substantial uncertainty in the scientific evidence available at the time. The document search and interviews showed that policy makers felt guilty about a previous experience in which people had become infected with HIV/AIDS through contaminated blood and were concerned about repeating this experience. Finally, in the UK, the possibility of blood contamination was seen as a much more urgent problem than in the US, because BSE and vCJD were found there first and there were far more cases. This meant that when the UK made its decision about whether to remove white blood cells from donated blood, there was less scientific evidence available. In fact, the main study that was relied on at the time would later be questioned.
What Do These Findings Mean?
These findings show that for this particular case, science was not the only factor affecting government policies. Historical and social factors such as previous experience, sense of urgency, public pressure, and the relative importance of different scientific networks were also very important. The study predicts that in the future, infectious disease–related policy decisions are unlikely to be the same across different countries because the interpretation of scientific evidence depends, to a large extent, on social factors.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0030342.
National Creutzfeldt-Jakob Disease Surveillance Unit, Edinburgh, UK
US Centers for Disease Control and Prevention pages about prion diseases
World Health Organization variant Creutzfeldt-Jakob disease fact sheet
US National Institute of Neurological Disorders and Stroke information about prion diseases