Auditory and Language Development Assessment of Newborns Aged One to Four Years Exposed to Gestational Zika Virus Infection: A Case Series

Abstract

The known neurotropism of the Zika virus (ZikV) suggests that auditory organs and their neural pathways may be affected by prenatal Zika infections. Among the possible manifestations are audiological and language disorders, but so far, the data in the literature are inconclusive. Objective: To describe early and late hearing disorders in children with Congenital Zika Virus Infection (CZVI) and evaluate the language development of this population between 14 and 47 months of age and its possible correlation with the alterations found in auditory exams. Methods: Longitudinal, prospective, observational study of newborns born in Juiz de Fora and its macroregion with confirmed diagnosis of ZikV infection during pregnancy. Participants were examined from one to four years of age for hearing using the transient otoacoustic emissions (TOAE) test, immittance testing and brainstem auditory evoked potential (BAEP), and language using the Bayley Scales of Infant Development—Third Edition (Bayley III). Results: 15 participants were included; eight (53.33%) presented alterations in at least one of the hearing tests, one had an early loss (6%) of sensorineural origin, and seven (46.67%) had a poor language performance. In the three (20%) participants whose audiological exams were altered, there was language impairment, and two (13.33%) participants had extensive malformations in the central nervous system (CNS), presented language delay, and hearing exams were within normality. Conclusion: Infants and preschoolers with CZVI may present early neurosensory loss and late hearing loss with fluctuating character. Even if there were no significant association between the audiological exams results and the Bayley III performance, in the present sample, language development was below expectations for the age in the participants who had alterations in the three audiological exams, when there is early hearing loss or extensive lesions to the CNS. The results reinforce the importance of audiological examinations, especially the BAEP morphological and auditory threshold, in monitoring cases of CZVI until at least three years of age.

Neurological Short-Term Outcomes of a Cohort of Children Born to Zika Virus-Infected Mothers in Barcelona

“…Neonatal seizures and stroke are characteristic of vertically transmitted infections. ZIKV is highly neurotropic with an affinity for placental tissue that leads to mother to fetus transmission and neurologic sequelae [ 16 , 17 ]. ZIKV in utero exposure has been associated with seizures and early-life strokes in children [ 16 , 18 , 19 ].…”

“…Recently more studies expressed the need for further follow-up to evaluate the long-term effects of intrauterine exposure to ZIKV [ 6 , 7 , 9 , 10 , 20 , 24 , 25 , 26 , 27 ]. They imply that ZIKV can induce a spectrum of subtle and silent injuries to the fetal brain that can appear through childhood and adolescence [ 17 , 19 , 20 , 24 , 25 , 26 , 27 ]. Although we cannot assess the relation between our results and ZIKV prenatal exposure, we agree on the need for further study on the long-term effects of ZIKV on the fetal brain.…”

Congenital Zika syndrome

“…The clinical features of CZS are a consequence of direct neurological involvement and intracranial volume loss, causing structural, and functional alterations 4,62,63 . Structural alterations include cranial morphology, cerebral and ocular anomalies, congenital contractures, and mainly microcephaly (Fig.…”

“…The clinical presentation of CZS is generally characterized by disruption in brain development, both embryonically and at the fetal level 20,85 , characterized by direct neurological disturbance followed by the collapse of the fetal cranial vault due to decreased intracranial hydrostatic pressure 4,62,63 .…”