Number of Human Victims of Mad Cow Disease May Be Small

At one time, estimates were that upwards of 100,000 people in Great Britain might die from Mad Cow Disease — the first time I ever heard of the disease was in a speech given by Howard Lyman in which he claimed the disease would prove worse than AIDS. These estimates have been steadily revised downward, and a recent study by French scientists suggests that the disease may peak at a couple hundred deaths.

The current research is based on a computer model of the disease that incorporates new assumptions about the disease.

One of the striking things about the variant CJD that is believed to originate as a result of Mad Cow Disease is that young people seem especially susceptible to it, as compared to the non-variant CJD — which is unconnected with Mad Cow Disease — which generally afflicts people over the age of 50.

The average age at death of victims of vCJD is only 28, while 93 percent of people who die from CJD are over the age of 50. This leads some researchers to conclude that for some reason, young people are especially susceptible to vCJD, and that as time goes by this will result in a fall-off of the number of cases and deaths.

The study, published in Science, says, “Our prediction of the epidemic of vCJD lies in the ‘optimistic’ end of the ranges of previously published figures, and this low value is in favor of a large species barrier between cattle and humans.”

Add to that, the fact that susceptibility to the disease seems to affect only a specific genetic subpopulation of individuals, and it may turn out that only a tiny number of people ever exposed to Mad Cow Disease ever have a chance to contract vCJD.

The study suggests that the total number of vCJD deaths is likely to be somewhere between 205 and 403, although these estimates are highly dependent on current information about vCJD and could change with new information.

Still, it is encouraging that the worst scenarios seem extremely unlikely at this point, and vCJD is unlikely to become a massive epidemic in Great Britain.

Sources:

CJD deaths ‘may have peaked’. The BBC, November 23, 2001.

Worst of Mad Cow May Be Over. Paul Recer, Associated Press, November 22, 2001.

Harvard Study: Risk of Mad Cow Disease in the United States is Low

On November 30 the U.S. Department of Agriculture release a study concluding that the risk of a Mad Cow disease outbreak in the United States is very low. The three-year study, conducted by the Harvard Center for Risk Analysis, concluded that current regulations governing the import of cattle as well as bans on feeding meat and bone meal to cattle make it extremely unlikely that U.S. cattle will become infected with the disease.

According to the report,

There appears to be no potential for an epidemic of BSE resulting from scrapie, chronic wasting disease or other cross-species transmission of similar diseases found in the U.S.

The current major debate over Mad Cow disease in the United States is whether or not cattle herds should be tested for the disease. So far, the United States has test only 12,000 head of cattle out of an estimated population of 100 million. In 2002, the USDA plans to expand that testing to 12,500 more animals.

In its coverage of the report, The New York Times quoted Mad Cow researcher Thomas Pringle as saying that such limited testing was a mistake. Pringle noted that nations claiming to be BSE-free had, in fact, found cases of the disease after ordering testing of cattle herds. Japan, for example, recently discovered several cases of Mad Cow disease after believing the disease had not reached its shores.

Still, American Meat Institute president J. Patrick Boyle argued that, “America’s B.S.E.-free status is not luck. The U.S. is free of many animal diseases that plague other nations, testaments to the success of government-industry efforts.”

Sources:

U.S. Mad Cow Risk is Low, A Study by Harvard Finds. Elizabeth Becker, The New York Times, December 1, 2001.

Report has final word on mad cow disease. Kay Ledbetter, The Amarillo Globe News, December 9, 2001.

How Many People Will Die from Mad Cow Disease?

As I noted last year, although initial predictions suggested that tens of thousands of people would die from variant Cretuzfeldt-Jakob disease (Mad Cow Disease), so far the number of new cases and deaths have been extremely small. Now, a new study suggests that in the worst case scenario only a few thousand people will contract the disease — not the 100,000 or so predicted by other researchers.

A lot depends on how existing numbers are interpreted. So far, very few people have been diagnosed with vCJD. From 1995 to 1999, for example, there were only 61 cases of the disease diagnosed in Great Britain, with 55 deaths. Altogether, only about 100 people have died from the disease.

Still, researchers at the Imperial College predict that as many as 100,000 people could die from the disease. This is predicated on the view that large numbers of people were exposed to Mad Cow-infected beef, but simply have yet to show any symptoms of the disease. Researchers published this month in Science offers an alternative view — that few people have contracted the disease because few people actually consumed Mad Cow-infected beef.

In their study, the researchers conclude that even if 12 million people in Great Britain were exposed to the disease, the incubation period in most cases would be far longer than current human life spans. They estimate that the total number of vCJD cases will be somewhere between a few hundred and several thousand.

“Even in the worst case scenario, there are never likely to be more than 100 cases of vCJD pre year,” researcher Huillard d’Aignaux told Reuters.

Sources:

UK study predicts fewer human ‘Mad Cow’ cases. John Griffiths, Reuters, October 25, 2001.

vCJD ‘epidemic’ might be waning. Pallab Ghosh, The BBC, October 26, 2001.

When Do Animal Rights Activists Agree with Animal Experiments?

Although animal rights activists claim animal research is wrong and inaccurate, when it is self-serving to do so, they will cite such research. This short bit from the e-mail newsletter of Americans for Medical Progress illustrates something that I see happen a lot:

Activist Benefits (Rhetorically) From Animal Research

Always eager to make the case against eating meat, virulent animal rights activist Adam Weissman (who was arrested last week at a demonstration at Huntingdon Life Sciences in New Jersey) cited animal studies to prove a link between “mad cow disease” and a human brain wasting illness.

Today’s post on AR News was of an April 7 Reuters newswire article citing a study published last week in the U.S. journal Proceedings of the National Academy of Sciences, dealing with the behavior of prions — the distorted proteins blamed for causing BSE and its human equivalent, new variant Creutzfeldt-Jakob Disease (vCJD) — in monkeys.

That pesky animal research sure has a way of coming in handy when you want to make a case. 🙂

Americans Who Have a Clue Protest PETA

Several people from People for the Ethical Treatment of Animals (including Bruce Friedrich) showed up at the National Veterinary Services Laboratory in Ames, Iowa, this week to protest the planned slaughter of more than 230 sheep. The sheep were confiscated by the U.S. Department of Agriculture based on the suspicion that they may have been exposed to contaminated feed that could put them at risk of developing a form of spongiform encephalopathy (Mad Cow Disease).

A group of 10 Iowa State University students showed up, in turn, to protest PETA. Calling themselves Americans Who Have a Clue, the students grilled hot dogs outside the USDA office and disputed PETA’s claims about the sheep slaughter.

“I’m here to let the USDA know that they’re doing their job and that there are people supporting them,” Loren Shetler told the Iowa State Daily. “How ethical would it be to let millions of livestock be slaughtered [if there were a major spongiform breakout in the United States]?”

Computer engineering sophomore Kevin Broulette said the group decided to grill hot dogs because, “We thought the protesters might get hungry, so we brought all this out.”

Source:

Iowa State U. students protest PETA at lab. Rebecca Cooper, Iowa State Daily, March 26, 2001.

Researchers stop BSE in mice

    A couple months ago, animal
rights activists trumpeted research providing the closest thing yet to
proof that bovine spongiform disease likely causes the human spongiform
disease CJD. Of course, the research in that case was done in mice which,
according to animal rights activists and groups, can never be accurately
applied to human beings. Now comes word of more such “useless” spongiform
research. An article in The Lancet reports that experiments in mice conducted
by scientists at the Serano Pharmaceutical Research Institute managed
to stop transplanted CJD from growing in mice.

    Spongiform diseases cause nerve
tissue proteins in the brain to fold abnormally, leading to the build
up of a destructive “beta sheet.” The Serano researchers exposed tissue
from the brains of CJD-infected mice to peptides which reversed the structure
of the proteins back to a form similar to the safe original.

Reference:

CJD treatment ‘draws closer.’ The BBC, January 14, 2000.

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