New tests for prion disease
The majority of the UK population and a lesser proportion of continental European and the rest of the world have been exposed to mad cow disease or BSE contaminated foods and this has resulted in the new human disease variant CJD (vCJD). Although the number of patients remains small, the number of people infected but without any signs of illness (termed clinically silent infecton, or carrier state) is unknown and could be large. The time from being infected to showing signs of the disease can be prolonged for up to 50 years. During this period infected individuals are themselves infectious and there is a risk of spreading the disease through the contamination of medical and dental instruments; the use of contaminated blood for transfusion and the transplantation of infected organs such as kidneys. All of these dangers pose significant challenges for the protection of public health and measures currently in place cost 100’s of millions of pounds per annum in the UK alone. To date there have been four confirmed cases of vCJD resulting from the transfusion of contaminated blood and several thousand patients know to have received contaminated blood products who are considered to be at risk. All of these problems can be avoided if simply tests were available to detect CJD infection in the peripheral blood of carriers.