Health

How a common viral infection can increase a child’s autism risk

Children born with a common viral infection are nearly 2.5 times more likely to be diagnosed with autism spectrum disorder, a new study finds.

Cytomegalovirus is part of the herpes family of viruses. It spreads through body fluids like blood, saliva and urine, and it’s usually harmless in healthy people. Around a third of infected mothers pass CMV to their fetus in utero.

About one in every 200 US babies is born with CMV each year. Nearly 20% of those infants will experience birth defects or other long-term health problems, such as hearing or vision loss, developmental delays or epilepsy.

CMV can be especially dangerous to babies, potentially resulting in hearing or vision loss, developmental delays or epilepsy.
CMV can be especially dangerous to babies, potentially resulting in hearing or vision loss, developmental delays or epilepsy. Jamey Ekins – stock.adobe.com

For this study, researchers from the University of Michigan and Centers for Disease Control and Prevention analyzed data on nearly 3 million children enrolled in Medicaid or the Children’s Health Insurance Program.

Just over 1,000 kids had congenital CMV, while nearly 75,000 had ASD. Autism is a developmental disorder that affects how people learn, behave, communicate and interact with others.

Autism is estimated to affect one in 36 American children. Here, a Brazilian woman bonds with her daughter, who is listening to an autism podcast.
Autism is estimated to affect one in 36 American children. Here, a Brazilian woman bonds with her daughter, who is listening to an autism podcast. Alexis Scholtz/peopleimages.com – stock.adobe.com

Girls born with CMV had 4.65 times the autism risk, while boys had about twice the risk compared to their peers without the condition.

The study findings were published in the June issue of the American Academy of Pediatrics journal Pediatrics.

“This data should prompt us as clinicians to proactively monitor for early signs of autism in children with congenital cytomegalovirus,” said lead study author Dr. Megan Pesch, a developmental behavioral pediatrician at University of Michigan Health C.S. Mott Children’s Hospital.

“This may be especially critical for children who are deaf or hard of hearing since diagnosing autism in this population can be particularly challenging,” added Pesch, whose daughter has congenital CMV and autism.

The link between congenital CMV and autism — which is estimated to affect one in 36 American children — has been suggested since the 1980s.

The idea is that CMV can activate an inflammatory state that may affect fetal brain development, thus increasing the risk of ASD.  

Pesch is calling for routine neonatal screening for CMV, which is often symptomless in pregnancy and at birth.

“Universal congenital CMV screening may not only improve detection before symptoms develop and lead to more timely intervention but also help us clarify the risk of autism among this population,” Pesch said. “Most importantly, this provides an opportunity to best support these children and their families.”