Fears that people still might be infected and carrying symptoms of the disease have started making rounds after a variant of CJD, the human form of the notorious made cow disease, has reared its head again.

The genetic make-up of a 30-year-old who recently succumbed to vCJD has hinted that some cases of the infection might take very long periods of incubation, maybe even decades, before coming out as a full-blown disease.

If the speculation turns out to be true, then there are still numerous people carrying the virus around, without any visible or noticeable symptoms. Experts are of the option that people with this variant of the mad cow disease could have contracted it by consuming beef contaminated with "the cattle disease bovine spongiform encephalopathy (BSE) as young children".

"The majority of the UK population have potentially been exposed to BSE prions but the extent of clinically silent infection remains unclear", experts believe.

The unusual case of the 30-year-old who died has been reported by medics from the MRC Prion Unit and National Prion Clinic at the UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery in London, in the journal Lancet.