BBC vCJD 'may develop over 50 years'

[Guest guest]

> * vCJD 'may develop over 50 years' *

>BSE could lurk in the human body for up to 50

>years before it develops into vCJD, scientists

>say.

>Full story:

>http://news.bbc.co.uk/go/em/-/1/hi/health/5106808.stm

>

vCJD 'may develop over 50 years'

A disease linked to cannibalism has given clues

about how long mad cow disease (BSE) can lurk in

the human body before it develops into vCJD.

 

A University College London team said it could

take 50 years for vCJD, the human form of the

disease, to develop.

 

They studied Papua New Guineans with a related

condition - kuru disease, which is contracted

through cannibalism.

 

In The Lancet, the team said people with a

certain genetic make-up risked long-term vCJD

incubation.

 

Exposure to BSE (bovine spongiform

encephalopathy) in the UK has been widespread,

although just 160 vCJD (variant

Creutzfeldt-Jakob) patients have been identified,

leading scientists to investigate why more people

have not been affected so far.

 

Kuru disease, like vCJD, is a prion disease. Prions are mutated proteins.

 

It reached epidemic proportions in some Papua

New Guinea communities early in the 20th Century.

 

Eating dead relatives as a mark of respect and

mourning was ritual practice until it was banned

in the 1950s.

 

In the study, 11 patients with kuru were

identified between July 1996 to June 2004, with

the last one born in 1959.

 

Although it was not possible to know the exact

date the patients contracted kuru, the possible

incubation periods ranged from 34 to 56 years.

 

Genetic differences

 

The researchers believe the incubation period

for BSE prions in humans could be even longer

than that seen in kuru because infection between

different species typically takes longer to

develop than one passed within the same species.

 

Professor John Collinge, who led the study, said

vCJD patients identified so far " could represent

a distinct genetic subpopulation with unusually

short incubation periods for BSE " .

 

He said a human BSE epidemic might have a number

of phases, and added: " Recent estimates of the

size of the vCJD epidemic based on uniform

genetic susceptibility could be substantial

underestimations. "

 

An editorial in the Lancet stated: " The eventual

size of the vCJD epidemic remains uncertain.

 

" The number of infected individuals is still unknown.

 

" By investigating kuru, the only known example

of a major epidemic of a prion disease, we will

begin to narrow our present uncertainties about

vCJD.

 

" Any belief that vCJD incidence has peaked and

that we are now through the worst of this

sinister disease must now be treated with extreme

scepticism. "

Story from BBC NEWS:

http://news.bbc.co.uk/go/pr/fr/-/1/hi/health/5106808.stm

 

Published: 2006/06/22 23:44:44 GMT

 

© BBC MMVI

 

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