Scientists believe the new test could be used to screen individuals who may unwittingly be carrying the infection and could also help to ensure the safety of donated blood, which can transmit the rogue proteins linked to the disease.
Experts have spent decades searching for an effective way of diagnosing variant CJD in people while they are alive. Currently the only certain way of establishing the presence of the disease is by examining brain tissue.
Professor James Ironside, head of the National CJD Research & Surveillance Unit at the University of Edinburgh, said: “This is the first time that we have been able to detect prions in the urine of patients with variant CJD. It opens the door to the development of a screening tool for people infected with CJD who do not show any symptoms, which is of particular concern in the UK for securing the safety of our blood supply.”
Variant CJD, which progressively destroys the brain and is always fatal, caused a major health scare when it first emerged in the UK in 1986. Scientists learned it was basically the same infection that caused bovine spongiform encephalopathy (BSE) in cattle.
The disease jumped into humans through the consumption of infected meat, notably beef burgers. It could also be transmitted via contaminated surgical instruments and blood transfusions. Despite fears of an epidemic, the disease proved very rare. Variant CJD has killed 229 people since it was first identified, including 177 from the UK.
But the infection can lie dormant for many years – possibly decades – before causing any symptoms. It has been estimated up to one in 2,000 people in the UK may be carrying the misshapen prion proteins believed to cause the disease.
The University of Texas’s test developed is highly sensitive and can detect tiny numbers of prions. The research is published in the New England Journal of Medicine.