Approximately one in every 150 children in the United States has autism or a closely related disorder -- a figure higher than most recent estimates -- according to a federal survey released Thursday, the most thorough ever conducted.
The new data do not mean that autism is on the rise because the criteria and definitions used were not the same as those used in the past.
But the sheer number of children apparently affected -- 560,000 nationwide, if the new statistics are extrapolated to all 50 states -- makes autism an "urgent public health issue" and a "major public health concern," said Marshalyn Yeargin-Allsopp, chief of the developmental disabilities branch of the Centers for Disease Control and Prevention, which conducted the survey.
The prevalence of autism, a poorly understood behavioral syndrome that interferes with a child's ability to relate to or interact with others, varies from state to state in the survey, with New Jersey standing out as a hot spot and Alabama and West Virginia having low rates.
The survey, which is to be updated regularly, offers no clues about what causes autism.