The claim that autism is linked to Lyme disease has been greatly exaggerated, according to researchers at Columbia University. Their findings are reported in a special issue of JAMA on child health.
Autism afflicts nearly one in 88 children in the US — although updated data from the CDC suggest this might be a drastic underestimate — but the cause of this neurodevelopmental disease remains a mystery.
Given these epidemic-like figures, some experts believe an infectious agent is at fault. Lyme disease, which is caused by the tick-borne bacteria Borrelia burgdorferi, has been one suspect, with previous studies claiming that as many as one in five children with autism had been infected.
"A proposed link between Lyme disease and autism has garnered considerable attention," said the authors. "However, controlled studies to assess evidence of infection with the causative agent of Lyme disease in patients with autism are lacking,"
This large, rigourous study, headed by Armin Alaedini, a researcher at the Columbia University Medical Center, examined blood samples from 120 kids: 70 with autism and 50 controls. Two screens could not consistently detect antibodies for the bacteria in the samples, a common readout that provides evidence for prior infection.
"The data do not address whether Lyme disease may cause autism-like behavioral deficits in some cases," said the authors, "However, the study's sample size is large enough to effectively rule out the suggested high rates of Lyme disease amongst affected children."