Watch those root canals

vCJD - Human BSE



Advisers warn of vCJD risk to dental patients

· Reused instruments present 'plausible' risk
· Department of Health to consider new advice
Tuesday May 9, 2006
Patients undergoing routine dental treatments for root canal problems may have been exposed to infection by the human form of BSE because instruments have been previously used on patients unwittingly carrying the incurable disease, government scientific advisers said yesterday.
About 3m such treatments are conducted every year in England and Wales alone. The scientists have told health ministers to consider banning the reuse of the equipment needed because of 'hypothetical but plausible scenarios' which suggest that person-to person cases of variant CJD might follow the shrinking number of animal-to-human cases.
The first wave of cases caused by infected food has so far struck only 190 people, mostly Britons, since the first death was announced in March 1996. But it has caused huge changes in animal rearing, food preparation, blood transfusions and surgical procedures.
Now the independent expert committee on BSE and variant CJD, known as Seac, says 'sufficiently rigorous' decontamination is difficult for the relatively unsophisticated dental instruments used to examine the pulp in teeth cavities. Seac says disposable, single use replacements 'would eliminate this risk, should it exist'. At the moment, around six instruments are used for each procedure and each can be reused eight to 10 times.
The suggested precautions followed Department of Health risk assessments which also say vCJD transmission via dentistry is plausible. Health officials have been cautious about recommending too many sweeping changes since a switch to single-use instruments for tonsillectomies in 2001 resulted in a big increase in bleeding complications and had to be reversed.
Three people are thought to have contracted vCJD infection through contaminated blood transfusions, a risk that had previously been described as theoretical. A recent study published in Lancet Neurology suggested as many as 14,000 people may be carrying prions, the rogue proteins implicated in diseases such as vCJD, without showing symptoms. Seac has urged the government to consider screening people through postmortems for hidden vCJD.
Seac, in a statement posted on its website yesterday, stressed there were still 'no definite or suspected cases of vCJD transmission' but said prions were more resistant to disinfection and sterilisation than other infectious agents and there was no data on vCJD infectivity in dental pulp.
The Department of Health said last night that it would consider Seac's 'precautionary' advice 'and then begin discussions with the relevant bodies ... there is a small but hypothetical risk that vCJD could be transmitted through [these] procedures. This is a complex area and Seac will review new evidence as it emerges.'