Autism in children said to be on the rise in the U.S.

Autism in children appears to be on the rise, according to US health officials who said Thursday the rate has risen 23 percent in two years, with one in 88 children affected.

Previous figures showed that as many as one in 110 US children had the disorder, leading autism research advocates to declare a new "national emergency" and an "epidemic" that needs urgent attention.

Officials admitted the rise may be due in part to improved identification of autism cases, particularly among children under three, but the extent of that influence on the overall number is unknown.

"There is the possibility that the increase in identification is entirely the result of better detection. We don't know whether or not that is the case but it is a possibility," said Centers for Disease Control and Prevention director Thomas Frieden.

"What we do know for certain is autism is common and needs to be effectively served," he told reporters.

The data in the CDC's Morbidity and Mortality Weekly Report found that autism spectrum disorder (ASD) is nearly five times more common in boys than girls, with one in 54 boys identified as having some form of the disorder compared to one in 252 girls.

The disorder was previously believed to be more common in boys than girls by a factor of four to one.

The data comes from surveys completed in 2008 at 14 US sites, showing that 11.3 per 1,000 eight-year-old children have been identified as having an ASD.

That marks a 23 percent rise over the last data from two years earlier, and a 78 percent rise over the total number of cases presumed in 2002 when the accepted estimate was that one in 150 children had some form of autism.

Since the data was culled from just 14 sites, it is not considered nationally representative -- so researchers stopped short of saying one in 88 children has autism in the United States as a whole.

But the findings are closely in line with what other research has shown, CDC experts said.

For Mark Roithmayr, president of Autism Speaks, the largest autism science and advocacy group in the United States, the new numbers are cause for alarm.

"Autism is now officially becoming an epidemic in the United States. We are dealing with a national emergency that is in need of a national plan," he said.

Costs associated with autism have skyrocketed in recent years, reaching $126 billion per year in the United States, or triple the figure it was six years ago, according to Roithmayr.

Autism includes a wide spectrum of developmental differences and may range from mild social awkwardness to complete inability to communicate, repetitive movements, sensitivity to certain lights and sounds, and behavioral problems.

Its cause remains a mystery. Parents are urged to seek professional help if their children are lagging behind on developmental milestones, such as not making eye contact, not pointing or not using language at an average rate.

"To understand more, we need to keep accelerating our research into risk factors and causes," said Coleen Boyle, director of the CDC's National Center on Birth Defects and Developmental Disabilities.

Rates of autism spectrum disorder varied widely in the report -- from one in 210 children in the southeastern state of Alabama to one in 47 children in the western state of Utah. New Jersey's rate was also quite high: one in 49.

New Jersey Congressman Chris Smith called the data "shocking" and "appalling" and urged a new national focus to eradicate the disorder akin to the effort that built the first US atomic bomb during World War II.

"Prevention, treatment and ultimately a cure for this developmental disability must be our highest priority. We need to bring a 'Manhattan Project' type focus to this essential life saving work," Smith said.

Early diagnoses were also on the rise for children under three, but a significant 40 percent of children in the study were not diagnosed until after their fourth birthday.

"When it comes to treating children with autism, the research suggests earlier is better," said Andrew Adesman, chief of developmental and behavioral pediatrics at Steven and Alexandra Cohen Children's Medical Center of New York.