NEW YORK (AP) – The government estimates that autism is becoming more common, but it's only a small increase, and some experts believe that this is largely explained by a better diagnosis of minority children According to a report by the Centers for Disease Control and Prevention, which focused on 8-year-olds, in 2014 one in every 59 US children had autism. That's the case in 2010 and 2012 for 1 out of every 68 children.
White children are diagnosed with autism more frequently than black or Hispanic children, but the gap has closed dramatically. Autism used to be 20 percent higher in white children than black children, and this difference shrank to 10 percent. The gap between white and Hispanic children shrank from 50 percent to 20 percent.
This increased recognition in minority children is likely a major reason for the overall increase, CDC researchers said.
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The causes of autism are not well understood, and it is not clear if other factors could be at stake – such as more couples, Having babies later in life said Thomas Frazier, chief scientist officer for the advocacy organization Autism Speaks
"There is still a lot of work to better understand why that happens," Frazier said about the rise.
There are no blood or biological tests for autism. It is identified by judgments about the behavior of a child. Traditionally, autism has been diagnosed only in children with severe language and social impairments and unusual, repetitive behaviors. But the definition is gradually expanding, and autism is now an abbreviation for a group of milder, related conditions.
The new CDC report is based on a tracking system in 11 states focusing on 8-year-olds because most cases are diagnosed at this age. Researchers are reviewing health and school records to see which children fulfill criteria for autism, even if they have not been formally diagnosed. It is one of three CDC autism estimates, but is considered the most stringent.
"It's the gold standard," said Alison Singer, president of the Autism Science Foundation, an autism advocacy and philanthropy organization.
The researchers collected data from Arizona, Arkansas, Colorado, Georgia, Maryland, Minnesota, Missouri, New Jersey, North Carolina, Tennessee, and Wisconsin and hooked up a network that included about 300,000 children. The 1 in 59 was an average: It was as high as 1 in 34 in New Jersey and as low as about 1 in 75 in five states.
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Why the difference? Researchers say rates are higher in states where they can access more records.
For years, the estimate rose in leaps and bounds, though it was not clear why. A report published in 2007 put the estimate at 1 in 150, or the equivalent of about a child in 5 or 6 classrooms. The new 1-in-59 number equals 1.7 percent.
Heather Cody Hazlett, a psychologist at the University of North Carolina, said the slight increase from 2012 to 2014 was not surprising.  Autism in adults: When should you be tested?
It explores new ways to recognize autism earlier. It is daunting that less than half of the autistic children are diagnosed when they are 4 years old.
There is still a time delay between the first illness of the parents and the diagnosis of children. Many doctors may be reluctant to jump to an autism diagnosis with a younger child because they try to be "careful and not alarming," says Hazlett.
But this can lead to a delay in therapy or other services.  Deborah Christensen of the CDC, one of the authors of the study, said, "We need to do more to make sure children with developmental concerns are evaluated quickly."
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