A new study published in MSphere, the journal of the American Society for Microbiology, found that women who suffered from an active genital herpes infection during pregnancy were twice as likely as those without the STD to give birth to a child who would become autistic.
The findings are preliminary, but the discovery may mean researchers have cracked open the door so that one day physicians will be able to treat, or even stop, some cases of autism before they manifest—while the child is still in the womb.
The Centers for Disease Control and Prevention reports autism affects one in 68 children in the United States. The disorder, generally diagnosed before age 3, impacts the child’s communication, social, verbal, and motor skills to varying degrees. Both cures and causes are largely medical mysteries.
“No two people with autism are alike. It impacts each individual in a unique way,” reports the American Autism Association. “There is no found cure or cause for autism.”
But the curtain has been pulled back a little with this latest study.
“We believe the mother’s immune response to HSV-2 [herpes] could be disrupting fetal central nervous system development, raising risk for autism,” said the lead author of the study, Milada Mahic, who also serves as a research scientist with the Center for Infection and Immunity and for the Norwegian Institute of Public Health.
The researchers are now trying to determine whether physicians ought to screen pregnant women for HSV-2 levels during office visits, and if so, how frequently.
They didn’t think the fetus was directly infected by the herpes virus, HSV-2, because such infections generally cause death. Rather, they think an inflammation near the womb led to distress in the fetus.
As Science Daily reports, “About one in five American women carries HSV-2, also known as genital herpes, a highly contagious and lifelong infection usually spread through sex. After an initial outbreak, HSV-2 virus lives in nerve cells and is often inactive, with flare-ups occurring with diminishing frequency as the body builds up immunity to the virus.”
As part of the study, scientists looked at the blood samples of 412 mothers of children with autism and 463 mothers of children without autism. The participants were part of a larger research project at the Norwegian Institute of Public Health. The samples were taken during week 18 of the pregnancy and again at birth. The samples were then analyzed for HSV-2 as well as for four other pathogens.
The results were surprising. Researchers discovered a correlation between testing positive for high levels of antibodies to HSV-2 in the blood samples and having children diagnosed with autism.
Even more surprising: the tie between herpes and autism was only seen among male children. At the same time, researchers aren’t sure what that finding means. Autism affects boys five times more frequently than it does girls, according to American Autism Association statistics.
Further, scientists found the autism was only present when the women tested high for HSV-2 antibodies during the early part of their pregnancies—when the nervous systems of fetuses are going through rapid growth—and not during birth.
The conclusions are still negligible but they could prove crucial to understanding autism and one day helping overcome it.
“The cause or causes of most cases of autism are unknown,” said the senior study author, W. Ian Lipkin, who also serves as the director of the Center for Infection and Immunity. “But evidence suggests a role for both genetic and environmental factors. Our work suggests that inflammation and immune activation may contribute to risk. Herpes simplex virus-2 could be one of any number of infectious agents involved.”