Zika false-negatives crush hopes through long-term neurodevelopmental effects

Though everything might appear normal at first for Zika victims in the womb, according to a new report from a multi-institutional research group led by Children’s National Hospital, the long-term effects on Zika-exposed infants can fly under the radar.

In fact, in 77 out of 82 lab-confirmed cases of Zika infection among mothers, affected babies showed no signs of the disease, be they brain abnormalities, eye problems, or congenital contractures. The problems became more visible at four to eight months and nine to 18 months of age when follow-up neurodevelopment tests were conducted.

“These infants had no evidence of Zika deficits or microcephaly at birth,” Dr. Sarah Mulkey, a fetal/neonatal neurologist at Children’s National Hospital and the study’s first author, said. “Neurodevelopmental deficits, including declines in mobility and social cognition, emerged in their first year of life even as their head circumference remained normal. About one-third of these newborns who underwent postnatal head ultrasound had nonspecific imaging results, which we believe are the first published results finding a link between subtle brain injuries and impaired neuromotor development in Zika-exposed children.”

The research effort enrolled Colombian infants and mothers, specifically. It was based on a series of fetal magnetic resonance images and ultrasounds during pregnancy, followed by the neurodevelopment tests afterward, which could be divided in two: the Warner Initial Developmental Evaluation of Adaptive and Functional Skills — a skill test of items like self-care, mobility, communication, and social cognition — and the Alberta Infant Motor Scale — a motor examination of infants in prone, supine, sitting and standing positions.

According to Mulkey, the results accentuate recommendations already made by the U.S. Centers for Disease Control and Prevention (CDC). Zika-exposed infants undergo long-term follow-ups to guarantee intervention is possible. The results of her team’s study were published in JAMA Pediatrics.