Posted on 06/22/2006 9:52:41 PM PDT by familyop
TORONTO (CP) - It could take half a century or more for someone infected with prions - the cause of mad cow-like diseases - to start showing symptoms, say researchers, who drew that conclusion after studying a similar illness among Papua New Guinean people who once feasted on their dead.
Their findings suggest that the number of human cases of variant Creutzfeld-Jacob disease (vCJD) could end up being much larger than originally suspected, say the researchers, whose study is published in Friday's edition of The Lancet.
With 160 cases, the United Kingdom has the highest number of recorded cases in the world of vCJD, although there also are cases in Canada, the United States, continental Europe and Japan. The disease, associated with eating beef infected with prions, causes wasting of the brain that progressively disrupts motor control and ends in death.
Prions are highly infectious misfolded proteins that lead to various forms of the disease in different species - from bovine spongiform encephalopathy (BSE) in cattle to scrapie in sheep and variant CJD in humans.
But another prion disease, called kuru, reached epidemic proportions in certain communities in Papua New Guinea, where consuming the bodies - including the brains - of deceased relatives was considered a sign of respect and mourning. Most of those who took part in the ritual were females of all ages and young boys.
While the incidence of kuru began falling after mortuary feasting was outlawed by the Australian government in the mid-1950s, more than 2,700 cases were recorded among the Papua New Guineans between 1957 and 2004.
In field research led by Prof. John Collinge of University College in London, the investigators identified 11 people with kuru between July 1996 and June 2004. All were born before 1960, when transmission by cannibalism is believed to have stopped for good.
The researchers determined that patients' incubation periods ranged from 39 to 56 years and could have been up to seven years longer. Genetic testing of the kuru patients showed they had a particular gene variation associated with extended periods of incubation and resistance to prion disease.
Collinge and his colleagues believe incubation for BSE prions in humans who ate infected beef could be even longer than that seen in kuru patients because infection between species typically takes longer than that within species - or, in the case of kuru, from person to person.
Patients with variant CJD identified so far "could represent a distinct genetic subpopulation with unusually short incubation periods for BSE," Collinge, head of neurodegenerative disease at the Institute of Neurology, University College London, said in a statement. "A human BSE epidemic may be multiphasic, and recent estimates of the size of the vCJD epidemic based on uniform genetic susceptibility could be substantial underestimations."
Commenting on the research, Dr. Adriano Aguzzi said he agrees with the researchers' conclusion that incubation periods for vCJD could exceed 50 years.
"I know there are still single cases of kuru that are appearing now in Papua New Guinea people," Aguzzi, an internationally recognized expert in prion disease from the Institute of Neuropathology at University Hospital in Switzerland, said Thursday from Zurich.
"I think that in the case of CJD it has been shown that . . . the mean incubation time was eight years. But there were also occasions when the disease came after two years . . . There were also cases which took much longer. And for the transmission of BSE to humans, I think it's realistic to expect that it might take a very long time."
Even so, Aguzzi doesn't believe the world will be overwhelmed with a vCJD epidemic in coming years. "My gut feeling is that there won't be a lot of cases, so I'm not expecting thousands of deaths.
"But what I think we must brace for is a period of time until we have seen the last case of BSE in humans. It may take a very long time until this story is finally over, and not only because of the transmission of BSE to humans, but also because humans will transmit to humans through blood transfusions and other things."
A Lancet editorial, praising the researchers for providing "a unique insight into the natural history of human prion disease," said the eventual size of the vCJD epidemic remains uncertain.
"By investigating kuru, the only known example of a major human epidemic of a prion disease, we will begin to narrow our present uncertainties about vCJD," the editors wrote. "Any belief that vCJD incidence has peaked and that we are through the worst of this sinister disease must now be treated with extreme skepticism."
Could it be that some Alzheimer's patients in fact have BSE?
Who knows. I wish I could find the link, but I once read a study where some medical students took a bunch of people who were supposed to have Alzheimers and drastically reduced the number of medications that these elderly were taking. About half of the elderly returned to normal rationality. This would seem to indicate that many elderly don't have Alzheimers but instead are overwhelmed by overmedication.
I do know that my mother-in-law began to act like she was getting Alzheimers but the symptoms went away when my wife got her to stop taking Paxil. The doctor prescribed it to her shortly after 9-11 because she was getting upset after spending 3 straight days watching the Twin Towers collapse over and over on CNN. My wife cured her by making her turn off the TV, stopping the Paxil and taking long walks. One wonders how many other elderly are simply drugged into irrationality through overmedication.
I know a woman whose mother died of it last year at 68. They initially thought she had Alzheimers but the progression of the disease was so fast they knew it was something else. In that situation her mother only lived a few months after onset of the symptoms.
So very true and have seen this with my own elderly parents. Some of the best "medication" is getting out and moving about plus regular B-12 shots work absolute wonders.
Symptoms of vCJD are quite a bit uglier than those of Alzheimer's.
...something like a more aggravated and terminal MS.
Isn't this Prion thing a weird, like, electric car?
Head Cheese..
Stay away from the Head Cheese...
"If it weren't for the Supreme Court, I'd be the Head Cheese!"
The perfect segway !!! LOL !!!
Le Fromage Principal...
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