Could we face the return of CJD? Experts fear it may lie dormant in thousands
The Daily Mail, Published 1 November 2011, Lois Rogers.
Holly Mills was a lively teenager about to start university. But with her whole life ahead of her, she suddenly found herself in the grip of tragedy.
Within the space of just a few months, the gregarious 18-year-old had become so severely brain damaged that she was unable to move or communicate.
Eight years on, Holly has to be fed through a tube into her stomach and shows no emotion or awareness of her tragic predicament. Her days are spent in heartbreaking, silent immobility.
Holly is one of only three people still alive after developing the full-blown symptoms of Creutzfeldt–Jakob disease (also known as new variant CJD, or vCJD) — the human form of mad cow disease.
Holly’s parents Peter and Linda, both 61, are devoting themselves to their daughter’s full-time care and to a programme of daily mental stimulation, in the belief they are keeping her brain alive until a treatment emerges that will help her.
While they and their three older children live in hope of a cure for Holly, there is growing concern that another CJD outbreak may be imminent.
New evidence collected by the Health Protection Agency (HPA) suggests that one in 4,000 people who were eating meat before 1996 is probably carrying CJD (after that date, cattle infected with mad cow disease were, theoretically, removed from the food chain).
That could mean that as many as 15,000 people nationwide could be affected. While this is in line with a previous survey, the latest findings suggest CJD might be more prevalent in older people.
The findings — which received little publicity when published a few weeks ago — are mid-way results of a programme testing 30,000 samples of tonsil and appendix tissue removed during routine operations across the country.
The aim was to look for evidence of ‘silent’ or symptom-free infection, though scientists admit the method used in the tests cannot identify CJD with total accuracy.
Until recently, a definite diagnosis of the disease in people who have the symptoms could be made only after death, because brain tissue analysis was required.
However, John Collinge, a professor of neurology and a leading expert at the Government’s CJD research unit at University College, London, has developed a blood test which can check if the disease is present by detecting evidence of the so-called prions or infectious proteins known to cause the disease.
He believes the number of people infected could be as high as one in 1,000 and says the CJD situation is ‘very worrying indeed’.
So far, there’s little official interest in investing the several million pounds needed to turn the blood test into the high-speed screening tool needed to bring it into routine use. Critics say this is because the Government fears what it might find.
Mad cow disease, or bovine spongiform encephalopathy (BSE), first emerged in Britain in 1986 as a result of ‘cannibalism’, when beef offal was fed to cattle, which are natural grass-eaters.
The proteins, called prions, that cause BSE were found in large quantities in the brains, spinal cords and spleens of cattle (although they were also subsequently discovered in meat tissue, too). When animal carcasses were ground down to form feed stuff for other cattle, prions were passed on.
They then colonised the brains of the cattle which ate them, and were passed to humans via cheap, mechanically-recovered meat — such as processed sinews and offal that were used at the time in school dinners and baby food.
In humans, the prions triggered the development of a new form of fatal human dementia called new variant CJD, which was first identified in 1996. These prions are entirely new infectious agents, completely different from viruses, bacteria or parasites.
Basically, they are faulty versions of healthy proteins in brain and nervous tissue that then induce their neighbours to become faulty. As a result, the brain cannot function: all signals are disrupted or shut down completely, leading to almost certain death.
A ban on using animal remains in livestock feed was imposed in 1989, and 4.4 million cattle were slaughtered to eliminate the disease. At the same time, a ban was imposed on the use of mechanically-recovered meat in products for human consumption.
By the mid-Nineties, when CJD fears were at their height, up to 3.5 million people were believed to possibly be affected. The risk appeared to be greater in younger people, although the reason isn’t clear.
But as new cases failed to materialise (according to official statistics, 168 people have died from CJD in the UK), the view of the Government and medical establishment was that the danger had passed.
However, the new data from the Health Protection Agency suggests the rate of infection is much higher than currently thought.
‘We do not know how many infected people there are or how many of them will develop it,’ Professor Collinge says.
‘The incubation period, where there are no symptoms, can last for decades.’
But it is not only the threat of a widescale re-emergence of the infection that worries experts. There is also the possibility of a new generation being exposed to the disease, as a result of a European Union decision to change the rules on animal feed.
Although CJD emerged from beef, experts say there is evidence of related diseases affecting other meat-producing animals if they are forced into cannibalism
Contrary to popular belief, BSE has not been wiped out. In fact, 11 cattle were diagnosed with it in Britain last year, although none entered the food chain.
Most young cattle slaughtered for meat are not believed to have developed sufficient infectivity to pose a risk to humans. Any animal more than 30 months old destined for the food chain is checked for BSE after it has been slaughtered.
The new concern is not cattle, however, but pigs and chicken. Earlier this summer, the European Commission announced it was relaxing the ban on using animal remains in livestock feed.
From next year, chicken meat will be used in pig feed and vice versa, to cut costs for farmers who otherwise have to rely on expensive imported soya beans for growth-promoting protein-based animal foods.
Although CJD emerged from beef, experts say there is evidence of related diseases affecting other meat-producing animals if they are forced into cannibalism.
Now a group of CJD-affected families, led by former Labour health secretary Frank Dobson, is to challenge the Government to hasten the development of the new blood test to give people the chance to check if they are infected.
The proposal has been given added urgency by the latest findings about CJD-infected tonsil and appendix tissue, but the Government has been dragging its feet, says Mr Dobson.
‘The projections I was given when I was health secretary in 1998 were that the total number of CJD cases could be anything between a few hundred and 3.5 million people,’ he said.
‘Until now, the only certain way of diagnosing CJD in people who have not yet developed symptoms is to analyse tissue after death.
‘Trials show John Collinge’s blood test works, but it needs investment to turn it into a proper screening tool that can quickly deal with a high volume of blood samples.
‘You would have thought the Government would want it to test blood supplies and get an accurate picture of how many people are infected. I can’t understand why they’re not getting on with this.’
Anxiety about CJD transcends party boundaries, with Tory MP Sir Paul Beresford joining Mr Dobson’s cause.
The reason Holly and the other two surviving CJD victims are alive is probably because their families fought court battles to be allowed to give them pentosan polysulphate
‘We need to find out the extent of the problem and what we need to do about it,’ he said.
‘Otherwise we will potentially see a flood of cases in our grandchildren.’
The parents of Holly, from Thornton Dale in North Yorks, are among those backing the campaign. ‘It’s too big an issue to ignore,’ said Peter Mills.
‘The evidence suggests there will be a second bout of this infection and we need the measures in place to test blood. There is clearly a risk from infected people who have no symptoms. Even if they don’t develop the disease, they can pass it on.’
Normal sterilising techniques do not remove the abnormal proteins which cause CJD from surgical or dental instruments because they survive high temperatures.
There have been at least six transmissions from hospital operations and four cases of CJD infections passed from three different blood donors. All those infected in these ways have died.
In the meantime, Peter and Linda are fully engaged in caring for their sick daughter. When she was diagnosed with the disease aged 18, she was within weeks of leaving home to study midwifery. In fact, her symptoms had been emerging over the previous two years.
At first the family put her fatigue and anxiety down to teenage depression. She had fainting fits two or three times at school when she was 16, but her GP assumed she would grow out of them.
But when Holly began losing weight and having difficulty walking, her parents realised something was wrong.
Her condition quickly worsened, but the CJD diagnosis — based on ruling out everything else — was a dreadful shock.
‘We were devastated,’ says Peter. ‘We think she caught it from the mechanically-recovered meat they used to put in baby food.
‘Once Holly became ill, it all happened very fast. Within a few weeks of the diagnosis she couldn’t walk or talk. We treat it like a head injury.
‘We want to stimulate her as much as possible. We talk to her all the time and, although she doesn’t respond, we are convinced she still has some functions.’
Every morning, a system of hoists and pulleys allows Linda to transport Holly from bed to a specially-built bath tub. Once she is washed and dressed, the three embark on an outing into the countryside. Come rain or shine, Holly’s parents guide her wheelchair along the cliff-top paths in the nearby seaside resort of Scarborough, or through the elegant surroundings of one of the local National Trust mansions.
The reason Holly and the other two surviving CJD victims are alive is probably because their families fought court battles to be allowed to give them pentosan polysulphate, an experimental drug currently unlicenced in the UK, injected into the brain which seems to prevent the final stages of the disease.
What lies ahead for Holly and the thousands of other CJD carriers remains to be seen. Campaigning with Frank Dobson, Sir Paul Beresford and the Mills family is Christine Lord, from Southsea, Hampshire, whose son Andy, a radio sports commentator, died aged 24 from CJD three years ago.
Other experts believe up to 60,000 could be affected
‘In one of the last conversations we had, Andy asked me to find out how he got ill and I promised I would,’ says Christine, a BBC journalist who is writing a book about what she believes has been a political cover-up of the extent of the CJD risk.
‘I want to know where this came from. I stopped him eating beef from the age of six because of BSE, but he still got the disease.’
She is organising a protest next month to demand access to the blood test.
‘I think the Government doesn’t want the test out there because of people finding out how prevalent CJD is,’ she says.
A spokesman for the NHS Blood Service said it was in talks with Professor Collinge about using his test to screen the 7,000 blood donations collected daily across the country, but could not say when the work would be done to develop a tool capable of bulk screening.
‘We are spending £40 million a year on a process to remove white blood cells and £200 million a year on synthetic blood-clotting factors to minimise the risk of CJD transmission via blood,’ she told the Mail.
Professor Collinge says blood will certainly already have been donated by infected donors.
‘I think the possibility of a lethal infection in one in 4,000 blood donors is very worrying. People wouldn’t accept that level of risk if it was HIV.’
The Government’s experts have extrapolated the Health Protection Agency’s data and suggested at least 15,000 people are carrying CJD, though they agree the exact figure is unknown and other experts believe up to 60,000 could be affected.
Meanwhile, Azra Ghani, professor of infectious disease epidemiology at London’s Imperial College, says the potential harm from symptom-free CJD carriers is impossible to predict.
‘It’s a waiting game with any new infection. We just don’t know if these people will be infectious or not.’