Three hundred thousand children. That's how many the Centers for Disease Control and Prevention reports suffer from autism. It has remained a baffling and often devastating disorder, and the new numbers show how widespread it is.
The CDC reported that 5.7 children out of every thousand -- one in 175 -- have the problem. And the total may be higher because many doctors do not recognize the early warning signs.
"Many children are not diagnosed with autism until they reach school age. And we need to change that," said Dr. Jose Cordero, director of the CDC's National Center on Birth Defects and Developmental Disabilities.
In two CDC surveys, boys outnumbered girls by four to one. Hispanic children seemed to have slightly lower rates of the disorder, though researchers say they may have less access to health care and are therefore reported less often.
Babies and toddlers with autism may seem healthy, playing and pointing and babbling. Then they may begin to withdraw, sometimes losing what speech they have learned, sometimes making repetitive motions, often losing the ability to respond to common social cues.
But the first signs can be subtle and easily overlooked by parents.
"Children with autism do show affectionate behavior," said Wendy Stone, a child psychologist at Vanderbilt University and the author of "Does My Child Have Autism?"
"They can show attachments," she said. "Social behavior is not a pervasive, all-or-nothing thing. It's a matter of degree."
That's a critical matter, because specialists say that while there is no cure, there are types of behavioral therapy that work best if you start early -- and you cannot start early unless you realize there is a problem.
"We do know that early intervention really does make remarkable differences in the outcomes for these children," Stone said.
The new report could not say whether autism rates are going up, but many doctors and parents believe they are. By the end of the year, researchers hope to complete an Atlanta-based study, showing whether there has been an upward swing.
The CDC, at least for now, did not address the question of what causes autism. Researchers generally believe there is a genetic factor -- autism does run in families -- but there may be more at work as well. Some advocacy groups believe certain preservatives in childhood vaccines may play a role, and the issue has become highly controversial.
In 2005, a combating autism bill was introduced by members of the Senate and House. It would mandate expenditures of $110 million a year for the next five years to advance research, screening and treatment. But it has been stalled in committee for a year.
"For eight years I've had parents and clinicians coming to me, saying we have an epidemic of autism, and many people in government are reluctant to accept that," said Rep. Dave Weldon, a Florida Republican who has worked on the issue. "I think the prospects for its passing are better, now that the CDC has really, finally admitted that we have an epidemic."