WASHINGTON, April 11, 2025 (BSS/AFP) - US authorities are conducting a large-scale study into the cause of the autism "epidemic," Health Secretary Robert F. Kennedy Jr. said Thursday.

"We've launched a massive testing and research effort that's going to involve hundreds of scientists from around the world," Kennedy said at a televised cabinet meeting chaired by President Donald Trump.

"By September we will know what has caused the autism epidemic. And we'll be able to eliminate those exposures."

Kennedy, a vaccine skeptic, who has long promoted a debunked theory linking childhood vaccines to autism, said the prevalence of autism has jumped dramatically in recent decades.

"The autism rates have gone -- from our most recent numbers, we think are going to be about one in 31 from one in 10,000 when I was a kid," he said, without offering more details or citing the source of the figures.

The US Centers for Disease Control and Prevention (CDC) currently puts the rate of autism in children in the United States at one in 36, compared to earlier rates of 1 in 150.

"That's a horrible statistic and there's got to be something artificial out there that's doing this," Trump commented.

Autism is a developmental disability, whose symptoms can include delays in language, learning, and social or emotional skills.

A 2022 review of autism prevalence worldwide pinned the rise on multiple factors, including "the increase in community awareness and public health response globally, progress in case identification and definition and an increase in community capacity."

There is also evidence linking advanced parental age to autism.