Zika may have led to negative outcomes in kids born with normal head size

During the 2015-2016 Zika epidemic, many seemed to believe that infants who had been exposed to the disease, but had a normal head size may have avoided adverse outcomes. However, an investigation in JAMA Network Open finds that this may not actually be the case.¹

Investigators ran a retrospective cohort study from May 2019 to June 2019. The prospective cohort included 296 infants who had antenatal Zika virus exposure and had been followed up since December 2015 at a tertiary maternity-pediatric hospital in Brazil.

Among the 296 children in the cohort, antenatal exposure to Zika virus was confirmed in 219 of the 296 children. Exposure was confirmed through positive maternal or neonatal polymerase chain reaction analysis or IGM serology results. Fifty-three of the children had congenital microcephaly.

Anomalies seen in children exposed to Zika included:

• Failure to thrive (38 of 53 children with microcephaly, 73 of 143 with normocephaly)
• Cardiac malformations (19 of 46 with microcephaly, 20 of 100 with normocephaly)
• Excess nuchal skin (16 of 22 children with microcephaly, 35 of 93 with normocephaly)
• Auditory abnormalities (13 of 50 children with microcephaly, 14 of 141 with normocephaly)
• Eye abnormalities (42 of 53 children with microcephaly, 28 of 158 with normocephaly)

Although fewer neurologic abnormalities were seen among children who were normocephalic than those who had microcephaly, children with normocephaly did have frequent neurologic abnormalities such as abnormal tone, hyperreflexia, feeding difficulties, abnormal brain imaging results, and congenital neuromotor signs. One hundred twelve children with normocephaly had Bayley-III evaluations. In this group, 72 of the children had average or above-average scores; 30 scored 1 standard deviation below average in at least 1 domain; and 10 score 2 standard deviations below average in at least 1 domain.

Reference

1. Cranston JS, Tiene SF, Nielsen-Saines K, et al. Association between antenatal exposure to Zika virus and anatomical and neurodevelopmental abnormalities in children. JAMA Netw Open. 2020:3(7):e209303. doi:10.1001/jamanetworkopen.2020.9303