Investigation of the Prevalence of Autism in Brick Township A Community Report
At the request of the New Jersey Department of Health and Senior
Services and congressional district representatives, the Centers for
Disease Control and Prevention (CDC) and the Agency for Toxic Substance
and Disease Registry (ATSDR) investigated if the rates of autism among
children in Brick Township, New Jersey were higher than expected.
Published prevalence rates were examined and researchers looked into
whether there were possible links to environmental exposures.
Autism is a spectrum of disorders that are complex and lifelong.
Individuals with autism have problems with social interactions and
communication skills as well as a tendency towards restrictive or
repetitive interests and behaviors. Autism spectrum disorders (ASD) is
a term used to describe the continuum of functioning among persons
with autism. ASD includes autistic disorder, pervasive developmental
disorder - not otherwise specified, and Asperger’s disorder as
defined by the American Psychiatric Association’s Diagnostic and
Statistical Manual - Fourth Edition (DSM-IV).
CDC’s expertise was called upon because of the complexity of
investigating a behavioral disorder such as autism and the fact that
CDC was developing epidemiologic methods that address the unique
challenges of autism.
The prevalence investigation identified children with possible
autism whose parents were residents of Brick Township during 1998. The
autism diagnosis was verified through a clinical assessment.
The rate of autism among children in Brick Township was 4.0 per
1,000 children aged 3 through 10 years. The prevalence of the more
broadly defined autism spectrum disorder was 6.7 per 1,000 children.
These prevalence rates are higher than rates reported in other
currently published studies from other countries.
Whether the Brick Township rate is unusual relative to other U.S.
communities is uncertain. No current data on the prevalence of autism
in the U.S. is available.
A few very recent studies in other countries have found high rates.
Service provider data in the U.S., e.g., special education data, show
increasing numbers of children with autism receiving specialized
services.
There is ongoing scientific discussion about whether higher rates
of autism worldwide reflect a true increase over time, a greater
awareness of these disorders, improved case finding techniques,
broader diagnostic criteria, or a combination of all these factors.
Other results from the Brick Township investigation:
Sixty of the 75 potential case children met the criteria
(DSM-IV) for an ASD.
Thirty-six of the children met the criteria for autistic
disorder.
There were twice as many boys than girls with autistic
disorder.
Sixty-three percent of the children had mental retardation.
Seven children had a brother or sister who also had an ASD.
Because of the lack of data on autism in the U.S., monitoring the
prevalence of these disorders in several communities across the
country would be helpful to identify the magnitude of this health
problem and how it varies in different population subgroups. In
addition, we need to do large-scale epidemiologic studies to begin to
understand the cause of this important health problem.
National Center for
Birth Defects and Developmental Disabilities, CDC
