Prevalence - Increasing Number of Children Identified

The Centers for Disease Control (CDC) and Prevention conducts ongoing investigations and surveillance activities in selected communities and states to document increases and possible causative factors. A recent study from the CDC, published in the Journal of the American Medical Association by Yeargin-Allsopp, et al. titled "Prevalence of Autism in a US Metropolitan Area," states that "the prevalence for autism was 3.4 per 1,000 (male to female ratio 4:1). Overall, the prevalence was comparable for black and white children." Yeargin-Allsopp and colleagues also found that "40% of children with autism were identified only at educational sources. Schools were the most important source for information on black children, children of younger mothers, and children of mothers with less than 12 years of education." The abstract from CDC is available by using a keyword search using the term "autism."

The CDC's MMWR Weekly for May 5, 2006 featured a report, "Mental Health in the United States: Parental Report of Diagnosed Autism in Children Aged 4 - 17 years: United States, 2003 - 2004". This report describes the results of an analysis of two nationally representative parent surveys, the National Health Interview Survey (NHIS) and the National Survey of Children's Health (NSCH), which asked parents whether their child ever received a diagnosis of autism. CDC analyzed 2003--2004 data from NHIS and data from the first-ever NSCH (collected during January 2003--July 2004) to 1) estimate the population-based prevalence of parental report of diagnosed autism in the United States and 2) assess parental reporting of child social, emotional, and behavioral strengths and difficulties and special-health care needs among children with and without reported autism.

The MMWR Weekly Surveillance Summaries for February 9, 2007 features three reports on prevalence of autism spectrum disorders: Prevalence of Autism Spectrum Disorders - Autism and Developmental Disabilities Monitoring Network, 6 sites, United States, 2000, Prevalence of Autism Spectrum Disorders - Autism and Developmental Disabilities Monitoring Network, 14 sites, United States, 2002, and Evaluation of a Methodology for a Collaborative Multiple Source Surveillance Network for Autism Spectrum Disorders - Autism and Developmental Disabilities Monitoring Network, 14 sites, United States, 2002.

The California Department of Developmental Services website on autism includes three reports issued to the CA Legislature: 1) Changes in the Population of Persons with Autism and Pervasive Developmental Disorders in California's Developmental Services System: 1987-1998, Epidemiology of Autism in California (2002), and Autistic Spectrum Disorders: Changes in the California Caseload An Update: 1999 through 2002.