JWissmille
2003-08-17 22:10:29 UTC
REPOST:
".......Roughly translated:
It's the germs, stupid...."
"..... Ewald says, the primary causes of today's "slow-burning
plagues" are parasites --viruses, bacteria and other infectious
microbes --whose long-term effects we have simply failed to recognize....."
The Real Hot Zone
In a bold new book, evolutionist Paul Ewald argues that viruses and
bacteria play a huge, hidden role in heart disease, cancer and other
modern plagues
By Geoffrey Cowley
NEWSWEEK Nov. 27 issue
Back in the 1880s, before tuberculosis had a known cause, experts
attributed it to a combination of risk factors -- things like
depression, bad ventilation, insufficient food and "family
predisposition". One standard textbook noted expansively that "the
idea of infection being a cause... still prevails in the South of
Europe".
FAST-FORWARD TO the 1980s, and you hear similar
accounts of peptic ulcers. The highly touted risk factors were
stress, smoking, alcohol and, of course, "genetic
predisposition." Never mind that an Australian researcher
named Barry Marshall was successfully giving himself ulcers
by swilling beakers of bacteria -- and curing them with
antibiotics. The textbooks didn't even mention his work.
We now know that TB and ulcers are infectious conditions, caused by
specific microbes and treatable with antimicrobial drugs. Yet we're
still laboring to explain most of our leading scourges -- cancer,
heart disease, mental illness, Alzheimer?s-- with long lists of risk
factors. In a compelling new book titled "Plague Time" (282 pages.
Free Press $25), Amherst College biologist Paul Ewald argues that
we're missing an obvious lesson here. Roughly translated:
It's the germs, stupid. Though genes and lifestyle are no doubt
important, Ewald says, the primary causes of today's "slow-burning
plagues" are parasites --viruses, bacteria and other infectious
microbes --whose long-term effects we have simply failed to recognize.
Ewald is not a virologist but a bold-minded evolutionist who, in past
work, has created a whole new framework for thinking about infectious
disease. To understand why microbes behave as they do, he considers
their ecological incentives. Cold viruses can't afford to be too
virulent because they require mobile hosts. (A dying cold sufferer
wouldn't get around enough to infect other people.) But
parasites that can survive outside their hosts don?t have to be
so considerate -- especially if they can travel from host to host via
mosquitoes or drinking water. A dying malaria sufferer is, if
anything, preferable to a healthy one from the parasite?s perspective.
All the person has to do to spread infection is lie still and get bit.
In "Plague Time" he takes a similar approach. By his
reasoning, our genes shouldn't cause much heart disease,
Genes that impede our survival tend to die out over time, as their
owners fail to reproduce. By contrast, the parasites with the best
tricks for exploiting us are the most likely to stay in the game.
There is no question that viruses and bacteria can take up long-term
residence in our bodies. Some hide deep within our
cells to avoid detection by the immune system, while others
disguise themselves to resemble our own tissues. And we know the
consequences can be serious. Suppose the immune
system catches sight of a streptococcal bug that normally evades
detection by masking itself as a heart cell. As the body attacks the
invader, it may demolish the organ as well.
The question is whether these chronic infections are as pervasive as
Ewald suspects. Some experts would scoff at the notion, but the recent
findings are impressive. "Until the1980s," he writes, "it was
generally not appreciated that women who were suffering and dying from
cervical cancer were the victims of a venereal disease epidemic".
Today it?s undeniable. Epidemiologists have puzzled for more than a
century over the link between sexual promiscuity and cervical cancer.
But over the past 15 years, studies have revealed that human
papillomaviruses, America?s most common sexually transmitted
pathogens, are present in some 93 percent of cervical tumors.
Scientists have even identified the proteins that HPVs use to release
the brakes on normal cell division.
TIP OF THE ICEBERG
Cervical cancer may be the tip of an iceberg. Less definitive studies
have linked childhood strep infection to obsessive-compulsive disorder
and Tourette?s syndrome. Traces of a virus that causes mammary cancer
in mice have been recovered from human breast tumors. Researchers in
Japan and Germany have linked borna virus --a brain infection seen in
horses, sheep and cats-- to schizophrenia and bipolar disorder in
people. And a growing body of evidence suggests that Chlamydia
pneumoniae, a common respiratory bug, may play a key role in coronary
artery disease, the leading cause of death throughout the Western
world. Since 1988, researchers have consistently found the bacterium
in clogged vessels but not in healthy ones. They?ve caused arterial
lesions in rabbits by infecting them with the germ. They have even
found hints that antibiotics can slow the progression of heart disease
in infected patients.
As these connections are borne out, they could change medicine as
profoundly during the 21st century as germ theory did in the 20th. The
question is whether they?ll get the attention they deserve. As Ewald
observes, "Those who control access to funding and the channels of
scientific communication tend to be believers in the established
views." When Edward Jenner hit upon the notion of a smallpox vaccine
in 1797, the Royal Society of London scolded him for risking his
reputation on something "so much at variance with established
knowledge, and withal so incredible." When the Hungarian physician
Ignaz Semmelweis figured out that physicians? unwashed hands were
causing fatal infections among new mothers at the University of Vienna
in the1850s, he lost his own position there. And though Barry Marshall
first reported his findings on the infectious cause of ulcers in 1983,
his peers ignored the discovery until 1990, when the National Enquirer
got hold of the story and told the world. Let?s hope the scientific
community is less slow to notice this book.
© 2000 Newsweek, Inc.
".......Roughly translated:
It's the germs, stupid...."
"..... Ewald says, the primary causes of today's "slow-burning
plagues" are parasites --viruses, bacteria and other infectious
microbes --whose long-term effects we have simply failed to recognize....."
The Real Hot Zone
In a bold new book, evolutionist Paul Ewald argues that viruses and
bacteria play a huge, hidden role in heart disease, cancer and other
modern plagues
By Geoffrey Cowley
NEWSWEEK Nov. 27 issue
Back in the 1880s, before tuberculosis had a known cause, experts
attributed it to a combination of risk factors -- things like
depression, bad ventilation, insufficient food and "family
predisposition". One standard textbook noted expansively that "the
idea of infection being a cause... still prevails in the South of
Europe".
FAST-FORWARD TO the 1980s, and you hear similar
accounts of peptic ulcers. The highly touted risk factors were
stress, smoking, alcohol and, of course, "genetic
predisposition." Never mind that an Australian researcher
named Barry Marshall was successfully giving himself ulcers
by swilling beakers of bacteria -- and curing them with
antibiotics. The textbooks didn't even mention his work.
We now know that TB and ulcers are infectious conditions, caused by
specific microbes and treatable with antimicrobial drugs. Yet we're
still laboring to explain most of our leading scourges -- cancer,
heart disease, mental illness, Alzheimer?s-- with long lists of risk
factors. In a compelling new book titled "Plague Time" (282 pages.
Free Press $25), Amherst College biologist Paul Ewald argues that
we're missing an obvious lesson here. Roughly translated:
It's the germs, stupid. Though genes and lifestyle are no doubt
important, Ewald says, the primary causes of today's "slow-burning
plagues" are parasites --viruses, bacteria and other infectious
microbes --whose long-term effects we have simply failed to recognize.
Ewald is not a virologist but a bold-minded evolutionist who, in past
work, has created a whole new framework for thinking about infectious
disease. To understand why microbes behave as they do, he considers
their ecological incentives. Cold viruses can't afford to be too
virulent because they require mobile hosts. (A dying cold sufferer
wouldn't get around enough to infect other people.) But
parasites that can survive outside their hosts don?t have to be
so considerate -- especially if they can travel from host to host via
mosquitoes or drinking water. A dying malaria sufferer is, if
anything, preferable to a healthy one from the parasite?s perspective.
All the person has to do to spread infection is lie still and get bit.
In "Plague Time" he takes a similar approach. By his
reasoning, our genes shouldn't cause much heart disease,
Genes that impede our survival tend to die out over time, as their
owners fail to reproduce. By contrast, the parasites with the best
tricks for exploiting us are the most likely to stay in the game.
There is no question that viruses and bacteria can take up long-term
residence in our bodies. Some hide deep within our
cells to avoid detection by the immune system, while others
disguise themselves to resemble our own tissues. And we know the
consequences can be serious. Suppose the immune
system catches sight of a streptococcal bug that normally evades
detection by masking itself as a heart cell. As the body attacks the
invader, it may demolish the organ as well.
The question is whether these chronic infections are as pervasive as
Ewald suspects. Some experts would scoff at the notion, but the recent
findings are impressive. "Until the1980s," he writes, "it was
generally not appreciated that women who were suffering and dying from
cervical cancer were the victims of a venereal disease epidemic".
Today it?s undeniable. Epidemiologists have puzzled for more than a
century over the link between sexual promiscuity and cervical cancer.
But over the past 15 years, studies have revealed that human
papillomaviruses, America?s most common sexually transmitted
pathogens, are present in some 93 percent of cervical tumors.
Scientists have even identified the proteins that HPVs use to release
the brakes on normal cell division.
TIP OF THE ICEBERG
Cervical cancer may be the tip of an iceberg. Less definitive studies
have linked childhood strep infection to obsessive-compulsive disorder
and Tourette?s syndrome. Traces of a virus that causes mammary cancer
in mice have been recovered from human breast tumors. Researchers in
Japan and Germany have linked borna virus --a brain infection seen in
horses, sheep and cats-- to schizophrenia and bipolar disorder in
people. And a growing body of evidence suggests that Chlamydia
pneumoniae, a common respiratory bug, may play a key role in coronary
artery disease, the leading cause of death throughout the Western
world. Since 1988, researchers have consistently found the bacterium
in clogged vessels but not in healthy ones. They?ve caused arterial
lesions in rabbits by infecting them with the germ. They have even
found hints that antibiotics can slow the progression of heart disease
in infected patients.
As these connections are borne out, they could change medicine as
profoundly during the 21st century as germ theory did in the 20th. The
question is whether they?ll get the attention they deserve. As Ewald
observes, "Those who control access to funding and the channels of
scientific communication tend to be believers in the established
views." When Edward Jenner hit upon the notion of a smallpox vaccine
in 1797, the Royal Society of London scolded him for risking his
reputation on something "so much at variance with established
knowledge, and withal so incredible." When the Hungarian physician
Ignaz Semmelweis figured out that physicians? unwashed hands were
causing fatal infections among new mothers at the University of Vienna
in the1850s, he lost his own position there. And though Barry Marshall
first reported his findings on the infectious cause of ulcers in 1983,
his peers ignored the discovery until 1990, when the National Enquirer
got hold of the story and told the world. Let?s hope the scientific
community is less slow to notice this book.
© 2000 Newsweek, Inc.