Zika-Exposed Babies Who Appear Normal at Birth May Develop Problems Later on

By Megan Brooks

January 08, 2020

NEW YORK (Reuters Health) - Infants exposed to Zika virus before birth but without congenital Zika syndrome (CZS) are at risk for neurodevelopmental delays as they get older, a new study shows.

"This study supports the recommendations by the Centers for Disease Control and Prevention to perform long-term follow-up of all infants exposed to ZIKV in utero, not just those with manifestations of CZS at birth," Dr. Sarah Mulkey of Children's National Hospital, in Washington, D.C., and colleagues say.

"Neurodevelopmental delays may be mild and subclinical and can influence multiple areas of development. Without standardized assessment, developmental abnormalities may not be detected, and opportunities to optimize early developmental intervention may be missed," they note in JAMA Pediatrics.

The researchers report neurodevelopmental outcomes out to age 18 months in a cohort of 70 Columbian infants with laboratory-confirmed in utero exposure to ZIKV, normal fetal MRI and ultrasonography findings, and no evidence of CZS or microcephaly at birth.

"Thus, these infants were expected to have low risk for subsequent neurodevelopmental deficits, yet these deficits emerged in the first year of life and without a reduction in head circumference," Dr. Mulkey and colleagues report.

Although many of the infants had normal initial neurodevelopmental scores (beginning at age 4 months), overall scores declined in some children as they aged, with the most decreases seen in the domains of mobility and social cognition, which could indicate impaired neurocognitive development, they observed.

Nonspecific findings on postnatal neuroimaging comprising lenticulostriate vasculopathy, germinolytic or subependymal cysts, and choroid-plexus cysts, were associated with lower scores on the social cognition domain and "may be potential risk factors for worse early neurodevelopmental outcomes," they note, adding, "To our knowledge, this study is the first to show that these nonspecific imaging findings may indicate subtle brain injury potentially associated with impaired neuromotor development."

In email to Reuters Health, Dr. Mulkey said, "Healthcare providers should continue to ask patients about Zika exposure and discuss risk for neurodevelopmental abnormalities in all exposed infants and children. Every child with in utero Zika virus exposure should continue to have neurodevelopmental assessments to school age, even if the child looks normal and is doing well. We continue to learn about the long-term consequences of in utero Zika virus exposure in children."

The authors of a linked editorial say the findings in this cohort "add to the growing evidence of the need for long-term follow-up for all children with Zika virus exposure in utero to ensure they receive the recommended clinical evaluations even when no structural defects are identified at birth."

"Although the clinical significance of these nonspecific findings is not yet clear, the importance of postnatal neuroimaging for all children with Zika virus exposure in utero was made extremely clear," write Dr. Margaret Honein and co-authors from the Centers for Disease Control and Prevention in Atlanta.

"Evaluation of infants solely at the time of birth is clearly inadequate, as growing evidence exists of infants with clinically normal assessments who subsequently developed neurodevelopmental issues and infants with documented microcephaly at birth whose microcephaly was resolved and whose neurodevelopmental assessment results were normal on follow-up," they add.

The study had no commercial funding.

SOURCE: https://bit.ly/37EpFWg and https://bit.ly/2rY5zab JAMA Pediatrics, online January 6, 2020.