12.2 Dealing with vCJD
Although the UK's BSE epidemic had been brought under control by 2004, relatively small numbers of cases of BSE continue to arise throughout the world. It would now take extreme carelessness for a BSE outbreak on the scale of that experienced in the UK to occur in another country. The concern now is that any level of BSE in a beef herd might cause some cases of vCJD. By the end of 2004, there had been 148 deaths from definite or probable vCJD in the UK. There have also been a small number of cases elsewhere (e.g. one in the USA in 2002 involving a woman who had been brought up in the UK, another in Ireland in 2004 involving a man who had never lived in the UK, and several in continental Western Europe).
As already discussed, precautions have been put in place to guard against the possibility of vCJD being passed on in blood transfusions or through the use of contaminated surgical instruments. There is also ongoing research into possible treatments for vCJD. Although drugs intended for treating diseases in humans normally take many years to develop because of the rigorous testing for efficacy and safety insisted upon by regulatory authorities and the requirement that informed consent be given by participants in trials, some exceptions have been made in the case of vCJD patients. For instance, in 2001 Stanley Prusiner was given permission to treat a UK patient with the antimalarial drug quinacrine. Unfortunately, this patient eventually died, apparently from liver complications triggered by the drug. However, Prusiner's team is trying to improve the drug's efficiency - for instance, by fusing together two quinacrine molecules. Pentosan polysulphate (PPS) is another drug developed for other purposes (in this case, treating infections of the urinary tract) that has been used to treat vCJD. PPS appears to stop abnormal prion proteins from forming clumps that cause neurons to die. One patient, who had been given only hours to live before PPS treatment began in 2003, was still alive 18 months later. Although PPS may have slowed down or even stopped vCJD's progress in this patient, it is certainly not a cure for the disease. [C R E D]
Is it right to 'fast track' possible vCJD treatments in this way? [R E D]
So far, vCJD has invariably proved fatal for the often young patients suffering a debilitating illness and their families are often desperate. It could therefore be argued that the purpose of these treatments, treating fatally ill patients, is ethically justified even though the process falls outside conventional ethical procedures.
On the other hand, this argument is seldom employed successfully for other diseases. Proper clinical assessment of new treatments almost always involves taking elaborate precautions against bias - such as adequate replication and randomised double-blind trials (in which neither the patients nor those administering the treatments or assessing their effects know which patients received the treatment under test and which a supposedly non-effective placebo). Such objective assessment is hardly possible for vCJD, particularly when drugs are used on an ad hoc basis on individual patients at various stages in the development of the disease. This makes it extremely difficult to decide whether a treatment has 'worked' and hence whether it would be effective if used for other patients.
Another line of research is to test tissue from tonsils removed during routine tonsillectomy operations for the presence of PrPSc protein in order to assess the prevalence of vCJD in the general population (see earlier discussions in this course).
In this type of research, it is usually arranged that the individuals from whom the tonsils were removed cannot be identified. What issues does this anonymity suggest to you? [C R E D]
In the absence of a cure for vCJD, should individuals be told that they might develop vCJD at some stage in the future? If so, how should they be told? What other information and support should be provided? If someone was told that they were incubating vCJD, this knowledge would almost certainly have major effects on their lives - ranging from possible psychological damage to life insurance implications. The presence of PrPSc protein might not lead inevitably to the development of vCJD. Even if it did, the likely timescale might well mean that many people would die of other causes before the symptoms of vCJD manifested themselves. On the other hand, if a treatment were developed that could control the development of vCJD if given early enough, then the question arises whether 'at risk' members of the population should be identified and given the option of availing themselves of the treatment.
Doubtless, the BSE and vCJD 'stories' will continue to develop. Moreover, it is entirely possible that TSEs will continue to challenge us to refine our ideas about some aspects of biology. Further issues related to the course themes are also bound to arise. The BSE/vCJD episode continues to influence the relationship between science and wider society - for instance with regard to public attitudes to genetic manipulation and nanotechnology.