Findings in asymptomatic neonates without microcephaly or evident neurological abnormalities on initial clinical examination
Of the 511 women with ZIKV in the region, there were 470 live-born infants with no microcephaly or other evident neurological findings detected at birth on physical exam. The subsample of 280 (59.6%) infants that were cared for at our hospital, had one or more additional assessments done. Except for maternal age, the 280 infants that were followed up, and their mothers, were not different at baseline from those that were not followed up, suggesting that they are representative of the entire cohort (Table S3). None of 244 tested infants failed the hearing screening. Of the 155 infants submitted to the ophthalmologic exam, two (1.3%) had ZIKV-related findings: glaucoma or focal epithelium pigment mottling. Of the 207(73.9%) infants submitted to cranial ultrasonography, one (0.5%) had major findings potentially related to ZIKV infection while 47(22.7%) had minor features. Seventeen of the 199 infants with a neurological evaluation within 3 months of age had a possible abnormality but a normal cranial ultrasonography. One of them had Down syndrome but no underlying comorbidities were detected in the remaining 16(8.0%) infants. The maternal ZIKV-infection occurred in the first trimester in 11(57.9%) of the 19 infants with subclinical abnormalities; the rest were in the second trimester. ZIKV-IgM was negative in all 13 infants tested.