New surgical cleaning process reduces risk of vCJD

Scientists say a new cleaning process will reduce the risk of hospital transmission of the human form of mad cow disease.

Since standard sterilising procedures do not destroy the abnormal prion proteins that cause the illness, doctors have always been concerned that variant Creutzfeldt-Jakob Disease (vCJD) could be transmitted by contaminated surgical equipment.

Apparently this new cleaning technique, could also be used to reduce infection risk from all forms of human prion diseases, progressive brain wasting illnesses, for which there is no cure.

vCJD is of particular concern because the infectious prion is found in the lymphoid tissue of the body, it is feared it could be spread through surgical equipment used on the spleen or tonsils and through blood transfusions.

Prion proteins, unlike viruses and bacteria, are resistant to high temperatures and stick quite firmly to metal surfaces.

But now a new technique, devised by researchers at the University of Edinburgh, is able to break these infectious particles down by using a high energy form of gas called plasma.

Professor Robert Baxter, of the university's school of chemistry, says they had an integrated strategy which aimed to provide a new approach to decontamination of surgical instruments which ensured that decontamination was effective.

According to the researchers, the system, which was funded by Britain's Department of Health, could be developed commercially.

Dr Helen Baxter, a member of the research team, explains the surgical instruments are put in a oven-like container in which they are cleaned, which could be used alongside other sterilising techniques, and would work on any residue left on a surgical instrument.

She says it cleans 1,000 times better than what is presently in place.

Ever since vCJD was first detected and linked to eating meat contaminated with mad cow disease in the mid-1990s, more than 150 people have died of the illness.

Scientists at Britain's Medical Research Council (MRC) have already developed a detergent to be used in large sterilising machines in hospitals to destroy prion infectivity and cut the risk of vCJD infection though surgical instruments.

The system is described in the Journal of General Virology.