Children who are exposed to Zika virus in utero may develop structural defects of the cranium such as microcephaly. Now we understand that even children born to Zika virus infected mothers may develop neurodevelopmental and neurosensory deficiencies in the second year of life – in the absence of microcephaly.
During the 2015-16 Zika virus epidemic in Rio de Janeiro, Brazil, a cohort was established of 244 pregnant women who tested positive for the virus. There were 223 live births in this cohort, and 8 of 216 babies were identified with microcephaly. Between 7-32 months of age, these children had clinical (hearing and eye exam) and neurological evaluations, the latter using the Bayley scales of infant development (which assess cognitive, language, and motor skills).