It is correct that there is no validated screening test for vCJD. However, there is a prion reduction filter that a govt expert committee has recommended for use in kids born after 1996 receiving red blood cell transfusions. The question is which party will adopt this recommendation and gradually implement prion filtration for the population as a whole. The answer may well be the Conservative Party based on the recent debate in the House of Commons!
www.theyworkforyou.com/debates/?id=2010-03-18b.1075.0&s=prion+filters+segment%3 A20714472#g1075.2
Paul Beresford (MoleValley, Conservative)
I suspect that thereason for the professor's opinion is that it is extremely difficult todetect the prion. However, there is afeeling-correctly-that the precautionary principle should be applied,although hopefully in a sensible manner.
Withthat in mind, I draw the Minister's attention to the decision in April2007 by the chief dental officer that dentists should not reuseendodontic reamers and files-by that, I mean single-patient use. This, Iunderstand-I may be corrected-was derived from research on mice thatwere particularly susceptible to variant CJD. The basis of thisthinking is that the removal of the prion fromstainless steel reamers is difficult, as I think we all accept.Stainless steel reamers are cheap and so not a particular economicproblem, even for dentists claiming that their fees are not largeenough.
Nowadays, however, most endodontists, orthose doing serious amounts of endodontics, are using nickel titaniumreamers. A number of specific designs are used in different techniques.Reputable nickel titanium reamers are expensive. I also understand thatcleaning the prion off nickel titanium is mucheasier than taking it off stainless steel. Treatment for a tooth thatneeds endodontic treatment is therefore made very much more expensive.It is time-consuming if done properly, especially if molar root canal isinvolved. The unit of dental activity award for molar root canal issmall, especially when compared with the alternative treatment, which isextraction using-surprise, surprise-stainless steel forceps, where thesame prion difficulty would apply. That mightexplain the apparent increase in NHS extractions andreduction in NHS endodontics-I expect a letter from the BritishDental Association telling me I am wrong.
Anumber of questions arise. Many stainless steel instruments and burs areused in dentistry, including forceps. If the research on thesesusceptible mice was so conclusive, one questions why the chief dentalofficer chose those reamers and whether he thought about extending hisban further. Of course, if he did, he would have to face the problem ofprobability versus application of the ban versus cost. Should the banapply only to stainless steel reamers? Should it not be applied tonickel titanium? In 2007 D-Gen and DuPont produced a new prion disinfectant called RelyOn prioninactivator to remove or de-activate the prionon instruments. I would be interested if the Minister could tell me-if not tonight, certainly ina letter-whether that product has been tested, because if so, it wouldbe sensible to introduce its use into the new onerous disinfection andsterilization regulations that dentists are now facing, before theregulations are finalised. That would be better than landing it on abeleaguered dental practitioner after he has installed the equipment formajor changes that are coming through.
In 2001,the Departmentof Health allocated £200 million to modernise NHS surgicaldecontamination, along similar lines to that descending on dentists now.Attempts have been made to produce single-use instruments for somesurgery, and I understand that plastic instruments were developed fortonsil surgery but proved a failure. New rules have also been brought inon contact lenses, and it would be interesting to see whether thosewould be applicable or useful.
However, the wayforward has to be blood transfusion filtering.Some 1.8 million blood units are donated in the UK annually, and SaBTOhas recommended the immediate P-Capt filteringof all blood for children. In the Prime Minister's letter to me, on11 February, following myquestion on this subject, he said that the introduction of the filter should be subject to the satisfactorycompletion of a clinical trial. I assume that he was referring to theongoing-long ongoing-PRISMstudy. I understand that the study is way behind schedule. There areprevious studies-I can draw the Minister's attention to them, if theyare not in her notes-and, as I have said, the filterhas a CE mark.
I ask the Minister to move now on blood filtering,initially for children and then for all. If it is good enough for theDepartment of Health to use the precautionary principle for endodonticfiles after questionable thought, the same principle should be appliedto blood transfusion filtering. Action onendodontic files is essentially fiddling around the edges. Bloodtransfusion filtering is central to reducing orstopping blood transfusion transference of prions,to the benefit of future generations. I am sure Health Ministers wouldnot like to be named in what I will call an "If only we had" report in20 to 40 years, when people are dying from variant CJD.