Human form of 'mad cow' disease twice as prevalent as previously thought, study reveals

Scientists do not know how many people may be incubating lethal disease vCJD without showing symptoms

Science Editor

Twice as many people as previously thought may be carrying the infectious agent responsible for the human form of “mad cow” disease, a study has claimed. Double the number of people were found with the unusual proteins linked to the variant form of Creutzfeldt-Jakob disease, which is believed to have passed from contaminated beef to humans.

A survey of more than 32,000 appendix samples has revealed that 16 samples were positive for the abnormal “prion proteins” found in variant CJD patients, a degenerative brain disease acquired from exposure to contaminated meat products. The appendix operations were carried out between 2000 and 2012 and the samples were taken anonymously from patients attending more than 40 hospitals in Britain in order to assess the prevalence of vCJD in the population.

So far only 177 people in the UK have been diagnosed with vCJD, along with about a further 50 patients in other countries. Scientists do not know how many people may be incubating the lethal disease without showing symptoms because as yet there is no simple blood test for prion proteins.

Scientists are assuming there is a pool of people who are incubating the brain disease because it takes many years and sometimes decades for the first symptoms to show. Estimating the size of this pool is important for assessing the risk of the infective agent spreading via blood transfusions and hospital equipment.

“These findings have important implications for the management of blood and blood products and for the handling of surgical instruments,” said Noel Gill of Public Health England and colleagues in a study published in the British Medical Journal.

The study found the risk of carrying the prion proteins was about the same for both young and old, as it was for men and women. It was also about the same for different regions of the country, the researchers said.

Sheila Bird, an epidemiologist at the Medical Research Council’s Biostatistics Unit in Cambridge, said that larger samples sizes of about 50,000 each for men and women were needed to make more accurate assessments of how many people may be unwittingly infected with vCJD prion proteins.

“After all, we’ve done BSE-testing in millions of cattle across Europe but not yet surveillance in 100,000 UK human appendices,” Dr Bird said.

Professor David Brown of Bath University, and a former member of the Government’s advisory board on BSE, said the abnormal prion protein is not only present in vCJD but in the sporadic form of the CJD that has nothing to do with bovine spongiform encephalopathy – “mad cow” disease.

“It is important to note the presence of the abnormal protein in the appendix does not confirm an individual will develop vCJD. As the authors themselves point out, the incidence of vCJD is very small in relation to those who were exposed to BSE,” he said. “Therefore this result does not indicate one in 2,000 people carry vCJD, and it could just be down to people who carry the abnormal protein in their appendix,” he said.

“This study suggests people from different age groups and from anywhere in the UK could get vCJD... At most the report suggests a broad range of people could be carriers of a prion disease, which was suspected anyway.”

Professor Azra Ghani of Imperial College London, said: “These results highlight the need to maintain both case surveillance, and precautionary measures to prevent onward transmission over the coming decade.”

Start your day with The Independent, sign up for daily news emails
Sport
sportSo, how closely were you paying attention during 2014?
News
One father who couldn't get One Direction tickets for his daughters phoned in a fake bomb threat and served eight months in a federal prison
people... (and one very unlucky giraffe)
Arts and Entertainment
Joel Edgerton, John Turturro and Christian Bale in Exodus: Gods and Kings
film
Arts and Entertainment
Brendan O'Carroll as Agnes Brown in the 2014 Mrs Brown's Boys Christmas special
tvCould Mrs Brown's Boys have taken lead for second year?
PROMOTED VIDEO
ebooks
ebooksA year of political gossip, levity and intrigue from the sharpest pen in Westminster
News
i100
Arts and Entertainment
Amy Adams and Christoph Waltz in Tim Burton's Big Eyes
film reviewThis is Tim Burton’s most intimate and subtle film for a decade
Arts and Entertainment
Jack O'Connell stars as Louis Zamperini in Angelina Jolie's Unbroken
film review... even if Jack O'Connell is excellent
Arts and Entertainment
Madonna is not in Twitter's good books after describing her album leak as 'artistic rape and terrorism'
music14 more 'Rebel Heart' tracks leaked including Pharrell Williams collaboration
Sport
Rooney celebrates with striker-partner Radamel Falcao after the pair combine to put United ahead
footballManchester United vs Newcastle match report
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Ashdown Group: Senior Marketing Executive- City of London, Old Street

£40000 - £43000 per annum + benefits: Ashdown Group: Senior Marketing Executiv...

Ashdown Group: Marketing Manager

£40000 - £43000 per annum + benefits: Ashdown Group: An international organisa...

Ashdown Group: Internal Recruiter -Rugby, Warwickshire

£25000 - £30000 per annum: Ashdown Group: Internal Recruiter -Rugby, Warwicksh...

Ashdown Group: Marketing Manager/Marketing Controller (Financial Services)

£70000 - £75000 per annum + benefits: Ashdown Group: Marketing Manager/Marketi...

Day In a Page

A Christmas without hope: Fears grow in Gaza that the conflict with Israel will soon reignite

Christmas without hope

Gaza fears grow that conflict with Israel will soon reignite
After 150 years, you can finally visit the grisliest museum in the country

The 'Black Museum'

After 150 years, you can finally visit Britain's grisliest museum
No ho-ho-hos with Nick Frost's badass Santa

No ho-ho-hos with Nick Frost's badass Santa

Doctor Who Christmas Special TV review
Chilly Christmas: Swimmers take festive dip for charity

Chilly Christmas

Swimmers dive into freezing British waters for charity
Veterans' hostel 'overwhelmed by kindness' for festive dinner

Homeless Veterans appeal

In 2010, Sgt Gary Jamieson stepped on an IED in Afghanistan and lost his legs and an arm. He reveals what, and who, helped him to make a remarkable recovery
Isis in Iraq: Yazidi girls killing themselves to escape rape and imprisonment by militants

'Jilan killed herself in the bathroom. She cut her wrists and hanged herself'

Yazidi girls killing themselves to escape rape and imprisonment
Ed Balls interview: 'If I think about the deficit when I'm playing the piano, it all goes wrong'

Ed Balls interview

'If I think about the deficit when I'm playing the piano, it all goes wrong'
He's behind you, dude!

US stars in UK panto

From David Hasselhoff to Jerry Hall
Grace Dent's Christmas Quiz: What are you – a festive curmudgeon or top of the tree?

Grace Dent's Christmas Quiz

What are you – a festive curmudgeon or top of the tree?
Nasa planning to build cloud cities in airships above Venus

Nasa planning to build cloud cities in airships above Venus

Planet’s surface is inhospitable to humans but 30 miles above it is almost perfect
Surrounded by high-rise flats is a little house filled with Lebanon’s history - clocks, rifles, frogmen’s uniforms and colonial helmets

Clocks, rifles, swords, frogmen’s uniforms

Surrounded by high-rise flats is a little house filled with Lebanon’s history
Return to Gaza: Four months on, the wounds left by Israel's bombardment have not yet healed

Four months after the bombardment, Gaza’s wounds are yet to heal

Kim Sengupta is reunited with a man whose plight mirrors the suffering of the Palestinian people
Gastric surgery: Is it really the answer to the UK's obesity epidemic?

Is gastric surgery really the answer to the UK's obesity epidemic?

Critics argue that it’s crazy to operate on healthy people just to stop them eating
Homeless Veterans appeal: Christmas charity auction Part 2 - now LIVE

Homeless Veterans appeal: Christmas charity auction

Bid on original art, or trips of a lifetime to Africa or the 'Corrie' set, and help Homeless Veterans
Pantomime rings the changes to welcome autistic theatre-goers

Autism-friendly theatre

Pantomime leads the pack in quest to welcome all