The U.S. Centers for Disease (CDC) control reports that autism affects 1 in 110 children, 1 in 70 boys. This means that 1% of children in the United States are currently diagnosed with autism. The CDC report, published in Morbidity and Mortality Weekly Report (MMWR), represents a staggering 57 percent increase of autism in the United States from 2002 to 2006, and a 600 percent increase in just the past 20 years.
The CDC survey assigned a diagnosis of autism spectrum disorder based on health and school records of 8 year olds in 14 communities throughout the U.S. Debate continues about whether this represents a true increase in the prevalence of autism. Changes in the criteria used to diagnose autism, along with increased recognition of the disorder by professionals and the public may all be contributing factors. Nonetheless, the CDC report confirms other recent epidemiologic studies documenting that more children are being diagnosed with an autism than ever before.
Data from an earlier report of the CDC's Atlanta-based program found the rate of autism was 3.4 per 1,000 for children 3 to 10 years of age. Summarizing this and several other major studies on autism prevalence, CDC estimates that 2-6 per 1,000 (from 1 in 500 to 1 in 150) children have autism. The risk is 3-4 times higher in males than females. Compared to the prevalence of other childhood conditions, this rate is lower than the rate of mental retardation (9.7 per 1,000 children), but higher than the rates for cerebral palsy (2.8 per 1,000 children), hearing loss (1.1 per 1,000 children), and vision impairment (0.9 per 1,000 children). The CDC notes that these studies do not provide a national estimate.