In the first study in the country on the incidence of autism among young children, the Centers for Disease Control and Prevention have confirmed that there was a striking number of autism cases in Brick Township, N.J., but found no link between the disorder and environmental factors in the town.
Agency officials, who traveled to Brick recently to report the findings of their yearlong investigation, also said that, while there were no other studies in the United States with which to compare their results, the overall prevalence of autism in the country might be higher than previously believed.
The study in Brick Township, prompted by the suspicions of one couple with two autistic children who noticed many other autistic children in their community, found a rate of 4 children with autism per 1,000 between the ages of 3 and 10. In the sample of 72,000 people, 36 children are autistic, the study found.
Studies in Europe, Asia
Some studies in Europe and Asia have indicated that as many as 2 of every 1,000 children have some type of autism, the officials said.
"The rates are higher than we previously thought in this country, and nationwide, they may be more in line with what we found in Brick," said Jacquelyn Bertrand, who headed the study.
The CDC's objectives were to verify the number of cases of autism in Brick among the children who lived there during 1998 and to examine whether the disorder was linked to chemicals in the township's drinking water, its former landfill and the Metedeconk River, where some residents swim.
It found no such link. But the number of cases surprised some people involved in autism research.
"The CDC's findings are astonishing," said Dr. Eric London, vice president of medical affairs for the National Alliance for Autism Research in Princeton, which funds autism research.
Autism is a disorder that affects a child's ability to communicate and function socially. It varies in severity and has no known cause and no cure.
No 'cluster' confirmed
The study did not confirm the presence of a "cluster" of autism cases, a term used by those who have tried to link cases of a disorder or disease, such as cancer, to a geographic location and its environment. But, London said, the study in Brick might indicate there may be more autism cases nationwide than anyone previously believed.
"The fact is that we simply do not have enough data to determine the prevalence of autism in this country," London said. "We do not know if this is an unusually high number or if it is representative of autism prevalence in the United States. Only through additional research will we be able to evaluate the strikingly high numbers found in Brick to determine if they reflect the population or if there are disparities in the rates in different geographic areas."
Some parents of autistic children said they were disappointed at the scope of the study, which was limited to children who had lived there in one year.
Sheryl and Bob Nichols of West Milford, N.J., have a 9-year-old son who is autistic. Nichols said she had contacted CDC officials to tell them she had lived in Brick Township until she was 20 years old, before she became pregnant with her son, but they did not include her in the study because she did not fit into their parameters.
"I still think it has something to do with the environment," Nichols said. "They just haven't found it. They didn't even interview us."
The call for the study of Brick Township's problem began through the actions of Bobbie and William Gallagher, who had two autistic children and found that many other autistic children lived near them.
The Gallaghers, with the help of a few other parents of autistic children, conducted their own rudimentary survey of the histories of these children and became concerned about a possible link between Brick Township's environment and the incidence of autistic births.