Audiological Findings in Children Suspected to Have Been Exposed to the Zika Virus in the Intrauterine Period

Abstract

Objective: To evaluate auditory manifestations in children born to mothers who had exanthema during pregnancy, suspected to have been exposed to the Zika virus (ZIKV). Study Design: Prospective observational. Setting: Tertiary referral center. Patients: Children born in Rio de Janeiro, Brazil, between April 2016 and September 2017, who were referred for newborn hearing screening (NHS). Intervention: The NHS was performed by the automated brainstem auditory-evoked potential test at an intensity of 30 dBHL (decibels Hearing Level) with the result presented as “PASS/FAIL.” A follow-up test was performed 6 months after the first examination. Main Outcome Measures: Hearing outcomes by audiological assessment. Results: Ninety-eight children were recruited and 78 underwent the NHS test. In the first evaluation, the FAIL NHS result was observed in 4 of the 78 children. Three were diagnosed with sensorineural hearing loss and one had conductive loss. Including the first and second evaluation, the frequency of audiological alterations was 5.1%. Of the four children diagnosed with hearing loss, two were carriers of ZIKV, one had suspected ZIKV infection, and one was asymptomatic with confirmed exposure to the virus. There was no progression of hearing loss or other hearing abnormality in the children by the time of the second evaluation. The group of nonexposed children (negative quantitative reverse transcription polymerase chain reaction for ZIKV) showed no hearing loss. Conclusion: Uni or bilateral sensorineural hearing loss was diagnosed in asymptomatic children at birth. These observations highlight the importance of periodic follow-up of patients with congenital Zika syndrome to better understand their long-term auditory clinical outcome.

Audiological follow-up of children with congenital Zika syndrome

“…Another Brazilian study conducted in the city of Rio de Janeiro from April 2016 to September 2017 revealed a rate of 5.1% of audiological alterations among the 78 children whose responses to automated brainstem auditory-evoked potential testing were evaluated in the first six months and at 12 months of age. This study similarly observed no progressive loss of hearing [9]. Overall, our findings align with the latest recommendations from the US Centers for Disease Control and Prevention (CDC) guidance for diagnosis, evaluation and management of infants with CZS, which no longer recommends a diagnostic ABR in the first year, if auditory screening is passed by automated ABR [30].…”

“…Current understanding of the syndrome is further limited by the lack of published longitudinal studies of children with intrauterine exposure to Zika virus [5] , [6] . In addition to classical cortical neurological damage, congenital Zika virus infection may also lead to functional disabilities, such as swallowing disorders, visual impairment in the absence of structural ocular abnormalities [7] , and hearing loss [4] , [8] , [9] , [10] , [11] . While there is strong evidence that children congenitally infected with Zika virus exhibit abnormalities at the time of delivery, several studies have reported late-onset microcephaly among infants born with a normal head circumference, raising the hypothesis that there may be continued viral activity in neural tissue, even after birth [12] , [13] .…”

Evolution of ocular defects in infant macaques following in utero Zika virus infection

“…The absence of detectable viral RNA and loss of antibodies has been described in a human infant with ocular defects and CZS (19). This further highlights the difficulty of determining the long-term impact of CZS, as a child who presents to the clinic with neurological or ocular abnormalities, but without a known history of ZIKV infection during pregnancy or detectable ZIKV or antibody, may pose difficulty establishing a causal relationship between the defect and in utero ZIKV exposure (49,50).…”

Neurodevelopment in Children Exposed to Zika in utero: Clinical and Molecular Aspects

“…Although few studies evaluated hearing in the ZIKV-exposed infants beyond neonatal screenings, sensorineural hearing loss (SNHL) appears to be infrequent and occurs in infants with microcephaly and other severe anomalies of CZS ( Leal et al, 2016 ). Among 70 children with laboratory-confirmed ZIKV infection and microcephaly in Brazil, 5.8% presented hearing loss (SNHL) ( Faria et al, 2020 ). This percentage was 3.8% among 78 prospectively ascertained infants likely exposed to the ZIKV in utero ( Faria et al, 2020 ).…”

“…Among 70 children with laboratory-confirmed ZIKV infection and microcephaly in Brazil, 5.8% presented hearing loss (SNHL) ( Faria et al, 2020 ). This percentage was 3.8% among 78 prospectively ascertained infants likely exposed to the ZIKV in utero ( Faria et al, 2020 ). Although we predicted that the conductive hearing loss secondary to otitis, upper airway congestion, and infections would be increased in these infants, no data are yet available.…”