But the rate of autism seems to be rising. In the same period last year, the department identified 416 new cases. Ten years ago it was estimated that autism affected 1 in every 10,000 children, but recent trends suggest that 1 in 500 children have some form of the disorder. Scientists who study autism have found several genes that appear to be related to the disorder, a virus that causes brain damage similar to autism in animals and elevated levels of growth factors in the brains of newborns who later develop autism and mental retardation. They are studying how environmental pollutants, like mercury from municipal waste incinerators, affect developing brains.
Autism is a developmental disorder with a wide spectrum of symptoms that range from mild to severe.
In severe cases, autistic children exhibit ritualized body movements, repeated touching and sniffing of objects and an insistence on following precise routines. They have trouble making eye contact, speaking clearly and relating to other people. The fears about the vaccine have been supported by researchers in England who found live measles virus in the intestines of recently vaccinated autistic children. Since the brain and intestines communicate chemically, the researchers theorized that the triple vaccine set off both autism and intestinal problems. Privacy Information Stay connected to the news that interests you with free e-mail alerts from The New York Times.