- Scientists are to investigate whether [variant Creutzfeldt-Jakob
disease], the human form of mad cow disease, can be passed on through dental
- The Health Protection Agency (HPA), a [UK] government
advisory body, will use mice to see if vCJD can be passed on from contaminated
dental instruments. They will also see if the mice show signs of the disease
in the tissue in their mouths. The risk is thought to be small, but comes
after concerns vCJD could be spread via donated blood and tissue.
- The government has taken measures to protect the blood
supply by banning donations from certain groups, including those who have
had blood transfusions since 1980, after it emerged 2 people may have been
infected after having a blood transfusion. There have also been concerns
about whether the prions responsible for vCJD can be spread by surgical
instruments, especially when used during brain surgery.
- The aim of the 3-year experiment is to give the Department
of Health more guidance on the risks posed by vCJD in dentistry and to
determine whether stricter advice on the best cleaning methods needs to
be issued. The study was outlined at the HPA's annual conference at the
University of Warwick, which heard an estimated 75 million dental procedures
are conducted in the UK each year and 2 million of these are invasive root
- Experts will also look at the different methods of decontaminating
surgical instruments, such as manual scrubbing, the use of sound waves
and washer disinfection.
- Researcher Joanne Dickinson said they believed the risks
from dental procedures were very small, but the study would help to quantify
them. "The Department of Health will have the information to decide
what the level of risk is and what measures need to be put in place."
- Janet Gibbs, of the Human BSE Foundation, a victim support
group, said while dental procedures were not thought to be the highest-risk
area, the research was still welcome. "I think it is best that we
investigate these things. There are concerns about this, we know of families
of people with vCJD who have struggled to see a dentist. But one concern
is that people will become alarmed before we know what the risks are."
- Test For Detection Of Prions In Blood
- Nature Medicine
- The following information has been abstracted from a
paper entitled "Detection of Prions in Blood", by Joaquin Castilla1,
Paula Saa1, & Claudio Soto1; at the Departments of Neurology, Human
Biological Chemistry & Genetics and Neuroscience & Cell Biology,
University of Texas Medical Branch, 301 University Boulevard, Galveston,
Texas, 77555-0646, USA and 2 the Centro de Biologia Molecular, Universidad
Autonoma de Madrid, Madrid 28409, Spain.
- "Prion diseases are caused by an unconventional
infectious agent termed prion, composed mainly of the misfolded prion protein
(PrPSc). The development of highly sensitive assays for biochemical detection
of PrPSc in blood is a top priority for minimizing the spread of the disease.
We have shown that protein misfolding cyclic amplification (PMCA) technology
can be automated and optimized for high-efficiency amplification of PrPSc.
- We show that 140 PMCA cycles leads to a 6600-fold increase
in sensitivity over standard detection methods. 2 successive rounds of
PMCA cycles resulted in a 10-million-fold increase in sensitivity and a
capability to detect as little as 8000 equivalent molecules of PrPSc. Notably,
serial PMCA enables detection of PrPSc in blood samples of scrapie-afflicted
hamsters with 89 percent sensitivity and 100 percent specificity. These
findings represent the first time that PrPSc has been detected biochemically
in blood, offering promise for developing a non-invasive method for early
diagnosis of prion diseases."
- NOTE -- Here are some essential earlier stories loaded
with data about the risks of transmitting CJD via exposure to blood and
the fact that re-usable medical and dental instruments are no longer fully-sterilizable.
- Evidence For CJD/TSE Transmission
- Via Dental Instruments
- Invasive 'Sterilized' Re-Usable Medical/Dental
- Instruments As Modes Of CJD/BSE Transmission
- Mad Cow Fears Rise Over Prion-Contaminated
- Re-Usable Surgical Instruments
- UK Won't Ban Re-Usable Surgical Instruments In
- Tonsil Removal Despite vCJD Concerns
- Scientists Warn Of Mad Cow/CJD Spread In
- Dental And Surgical Procedures