Zika: 1 in 3 toddlers with prenatal exposure have neurodevelopmental issues

Takeaway

• Around one-third of children (median age, 18 months) who were exposed to the Zika virus (ZIKV) during pregnancy show neurodevelopmental and/or neurosensory abnormalities in a prospective cohort.
• Some with a normal exam at birth developed delayed abnormalities, including autism, whereas others with abnormalities at birth showed improvement.

Why this matters

• Further improvements might be possible with neurocognitive interventions.
• Clinicians need to know what kinds of abnormalities to monitor.

Study design

• Prospective cohort (n=216) of antenatally ZIKV-exposed toddlers in Brazil (aged 7-32 months; median age, 18 months). ZIKV exposure was confirmed by reverse transcription PCR.
• Neurodevelopment was assayed by the Bayley Scales of Infant and Toddler Development, third edition (Bayley-III; n=146), and through neurodevelopmental questionnaires/neurological examinations (n=70).
• Complete eye examination and hearing assessments were also performed.
• Funding: Ministry of Health, Brazil; NIH; others.

Key results

• 31.5% of children showed below-average neurodevelopment and/or abnormal vision or hearing assessments.
• Among the 146 children assessed by Bayley-III:
  • 12% scored below −2 standard deviations (score, <70 out of 100).
  • 28% scored between −1 and −2 standard deviations (score, 70-85).
  • 35% of children showed abnormal language.
• 49% (24/49) with abnormalities at birth had normal assessment.
• 25% (17/68) with normal assessment at birth showed neurodevelopmental defects, including secondary microcephaly or autism.

Limitations

• No control group.