Autism Rate Is Still Rising Despite Vaccine Change

[Guest guest]

http://online.wsj.com/article/SB119973993129672867.html?

mod=googlenews_wsj

Autism Rate Is Still Rising Despite Vaccine Change

By JENNIFER CORBETT DOOREN

January 7, 2008 4:12 p.m.

WASHINGTON -- Researchers at the California Department of Public

Health said autism rates in that state have continued to rise despite

the removal of the mercury-containing preservative thimerosal from

most childhood vaccines.

The research, which is being published in this month's Archives of

General Psychiatry, looked at autism rates of children ages 3 to 12

from 1995 through March 2007 who had active cases with the

department, or those who were receiving services from the state for

an autism disorder.

In 1999 federal health officials recommended the elimination of

thimerosal from children's vaccines on concerns about a possible link

to rising autism rates seen in the 1990s.

In 2004, the Institute of Medicine concluded there wasn't a

relationship between the mercury-containing vaccines and autism, but

recommended researchers continue looking at autism rates as

thimerosal exposure dropped.

Autism is characterized as impairments in social interaction,

communication, and unusual behavior and interests. The cause of the

disorder isn't known, and there is no cure, although medication and

therapy can improve symptoms. Other states besides California have

also reported an increase in autism rates.

Federal health officials have said part of the increase in rates,

which fall under a broader definition known as autism spectrum

disorders and also include Asperger's syndrome and pervasive

developmental disorders, may be because of better and earlier

diagnosis of the problem.

Indeed, the data from California's Public Health Department showed

the estimated prevalence of autism for children at each year of age

from 3 to 12 increased throughout the study period. The autism rate

of children age 3 in 1993 was 0.3 per 1,000 births and rose to 1.3

per 1,000 for children age 3 in 2003, or the age at which many

children enter the state system.

Researchers also looked at autism rates of children ages 3 to 5 based

on quarterly reports from the department to include those born after

1999, or children who received vaccines with little or no thimerosal.

The data showed the autism rate in January 1995 was 0.6 per 1,000

live births and rose to 4.1 per 1,000 live births as of March 2007

among children ages 3 to 5.

The study authors said if there really was a thimerosal link that

autism rates should have started declining in 2004, or when the first

group of children coming into the California Public Health

Department's system would have received thimerosal-free vaccines.

The study's lead author, Schechter, a medical officer with the

department, said the data only include children who qualify for and

are receiving state services and likely wouldn't include children

with milder cases of an autism spectrum disorder.

He said eligibility requirements for state services were tightened in

2003. He said the department will continue tracking autism rates and

is involved in other research looking for possible causes of the

disorder, like environmental factors such as exposure to pesticides.

Last year the Centers for Disease Control and Prevention said data

from 14 states showed 6.6 children per 1,000 have an autism disorder

as of 2002, which is higher than previous CDC estimates of 5.5 per

1,000 children. The CDC now has a more comprehensive effort underway

to track autism rates.

California researchers noted that from 1995 through March 2007 the

rate of all developmental disabilities increased from 5.4 to 9.5 per

1,000 live births, but that rate of increase was slower than the

autism increase.

Fombonne, a psychiatrist and autism researcher at Canada's

McGill University who has consulted for the Institute of Medicine and

the American Academy of Pediatrics, wrote in an accompanying

editorial that increased awareness of the disorder and broader

definition and diagnosis of it " have played a major role in

explaining the increasing numbers of children identified with

autism. " Fombonne said none of his research has been funded by

pharmaceutical firms.