Autism is on the rise in the U.S. That's according to a new government study released last week that found about one in every 110 U.S. children has been diagnosed with an autism disorder. That's an increase of 57 percent over 2002, when a study found autism in one in every 150 U.S. children.  

The report, released by the Centers for Disease Control and Prevention (CDC) noted that the rise in cases was driven partly by better detection of the brain disorder. But the CDC also said the possibility that children face an increased risk of developing autism symptoms "cannot be ruled out."

The CDC study examined the diagnoses of more than 300,000 8-year-old children in select communities across 11 states. They found 2,757 of the children studied, or roughly 1 percent, had been diagnosed with autism.

Catherine Rice, a CDC scientist and the study's lead author, said a combination of factors likely explained the rising number of cases. One, she said, is "better detection, particularly among children who may not have come to attention in the past, including girls, Hispanic children and children without cognitive impairment."

Diagnoses among Hispanic children rose 90 percent in the latest study. Autism among white youths rose 55 percent and they were far more likely to be diagnosed than African-Americans or Hispanics. The diagnosis rate among black children went up 41 percent.

Dr. Rice also said the CDC is researching the reasons for the actual increase in the number of autistic children. Environmental factors, including vaccinations, household products and diet, as well as genetics are being explored as potential causes.  

Autism cases rising, but why?
Are more children suffering from autism, or are researchers getting better at detecting the disease?