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Ped Med:
Seeking allies in autism fight
By LIDIA WASOWICZ
September 28, 2006
UPI Senior Science Writer
SAN FRANCISCO,
Sept. 28 (UPI) -- Parents' push for progress in autism research and
discovery has meant a pull for political allies.
As families of
children with the disorder and their supporters appear before
federal committee hearings and state health panel reviews to demand
long-overdue attention and action, some congressional and community
leaders are starting to line up behind their cause.
Among others,
Rep. Dave Weldon, R-Fla., a medical doctor and persistent critic of
the use of thimerosal in vaccines, has sponsored legislation to ban
the mercury-based preservative from flu shots. The compound has been
phased out of most childhood vaccines.
Rep. Dan Burton,
R-Ind., called congressional hearings in April 2002, when he was
chairman of the House Government Reform Committee, to investigate an
autism link to childhood vaccines after his grandson was diagnosed
with the disorder.
Regardless of its
scientific merit, the idea of a vaccine connection to the disorder
appears to have garnered broad grassroots interest, he said, noting
47 percent of parents who contacted their representatives believe in
such a link.
Among those
testifying, Dr. Andrew Wakefield -- whose controversial research
suggests the measles virus may be linked to inflammatory bowel
disease in children with developmental disorders -- described
finding traces of the microorganism in the small intestines of 75 of
91 youngsters with autism but in only five of 70 children without
the disorder.
Although the
study did not look at the role of the measles-mumps-rubella vaccine,
and in fact did not even determine whether the children had received
the immunization, it set off a wave of speculation implicating the
attenuated virus contained in the shot in neurodevelopmental
disorders -- a notion the American Medical Association and other
major health groups discount.
Perhaps because
the stakes are so high or the passions run so deep, in the last
decade few pediatric disorders have managed to capture as much
attention on the political stage and in the popular and professional
press as has autism.
Even so, fewer
still leave so many vital issues fluttering in the wind of
uncertainty.
When it comes to
this perplexing disorder, which affects an estimated 48 million
people worldwide, questions of causes, cures and even counts
continue to elicit an unsettlingly diverse range of interpretations.
This is
troublesome because disagreement on one key piece of the puzzle
translates to lack of consensus on the bigger picture. Getting a fix
on the range of a problem, for example, is a critical step toward
reaching its roots and rectifying its remedies.
When the long-
and widely held notion of autism as a response to cold-hearted
parents was finally nixed in the late 1960s, a view of the disorder
as an unavoidable genetic fate took hold in its place.
But that theory,
too, simply doesn't add up if the reported exponential expansion in
case numbers represents a true peak in prevalence. No hereditary
factor alone could cause such a dramatic rise in rates over a single
generation. In short, there is no such thing as a genetic epidemic.
"(The issue of
numbers) is a really important question because from the standpoint
of cause ... it's going to be difficult to explain a ten-fold or
even five-fold increase or any increase based on genes; they don't
change in a decade," said Dr. Thomas Insel, director of the National
Institute of Mental Health in Bethesda, Md.
Thus, if the
autism numbers are correct, scientists must look for additional,
non-genetic influences to explain them.
"Research
suggests environmental factors may combine with genetic
predispositions to contribute to the increased incidence in autism,"
said Judy Van de Water, associate professor of rheumatology, allergy
and clinical immunology at the University of California, Davis,
School of Medicine and Medical Center and the M.I.N.D. Institute.
While a strong
genetic component in autism is now generally accepted, there's no
consensus on the non-hereditary contributors to the disorder.
"We are always
wanting to look at what would be the environmental change over this
period that could lead to this increase," Insel said.
"The way to
disentangle that is to find places where it hasn't happened. I
haven't yet heard of a place where ... someone can say, well, you
know, the rate was one in 1,000 in 1990, and in (2006), it's still
one in 1,000."
As it is, experts
can't even uniformly say whether the enormous inflation in reported
autism cases in the United States in fact represents a swelling rate
of the nation's children affected by the disorder.
The question is a
central one in the vaccine debate.
If in fact the
disorder has strikingly increased in prevalence -- not just in
recognition -- then the idea that it's primarily a genetic condition
doesn't hold up.
But if there have
always been people with autism in reasonably similar numbers, then
the notion that a new trigger, like childhood shots, is behind it
begins to look implausible if not impossible.
Problem is that
question has not been settled.
"Alarm over the
possible 'epidemic' of autism, fueled by new epidemiological studies
and fanned by the rapid proliferation of Internet and media coverage
of the research, has prompted the medical community to clarify this
trend and its causes," one group of researchers wrote in a report
that called attention to a troubling spike over the previous dozen
years in the number of children diagnosed with and receiving
disability benefits for a wide array of conditions that fall under
the "autism spectrum disorders" umbrella.
"This leaves us
to grapple with troubling questions: Is there a true increase in the
prevalence of ASD? If yes, why? If not, what explains the growing
number of studies that report alarming rates?"
Citing lack of
evidence of its involvement, the one suspect the scientists crossed
off their list was the MMR vaccine.
In that, they
weren't alone.
Having come up
empty-handed, numerous investigators also have dropped their case
against the shot. These include groups that compared autism rates in
children who had and had not received the immunization in the United
States and Denmark and scientists following up on British youngsters
who did and did not develop the disorder after being inoculated
against the triple infectious threat.
In addition, a
comparison between children with and without autism showed little
difference in the age at which both groups received their first MMR
vaccination.
Despite those
votes of confidence, the shot does not appear to be entirely off the
hook.
Other teams,
including one taking a second look at the widely cited Denmark study
of more than half a million children, have come to less certain
conclusions and have called for further investigation.
The government
has indicated a willingness to oblige.
Emphasizing the
preponderance of current scientific research fails to show a
connection between the MMR vaccine and autism, the Centers for
Disease Control and Prevention nevertheless concedes on its Web site
that it "recognizes there is considerable public interest in this
issue, and therefore supports additional research regarding this
hypothesis."
Others have put
forth a mix of other factors -- improved diagnosis, greater parental
and professional awareness, the emergence of new services and
incentives for children to receive them, a broadened definition that
takes in youngsters with milder symptoms as well as possible unknown
genetic or environmental influences -- to help explain at least part
of the dramatic increase in the autism caseload.
(Note: In this
multi-part installment, based on dozens of reports, conferences and
interviews, Ped Med is keeping on eye on autism, taking a backward
glance at its history and surrounding controversies, facing facts
revealed by research and looking forward to treatment enhancements
and expansions.)
Next: Ascribing
meaning to climbing autism numbers
--
UPI Consumer
Health welcomes comments on this column. E-mail:
lwasowicz@upi.com
http://www.upi.com/ConsumerHealthDaily/view.php?StoryID=20060928-042439-2141r
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