Beyond hearing loss: exploring neurological and neurodevelopmental sequelae in asymptomatic congenital cytomegalovirus infection.

Congenital cytomegalovirus (cCMV) infection is common, and usually clinically inapparent. The prevalence of infection is approximately 1:200 births, but only 10-15% of infants have clinically apparent CMV disease (CACMV) as newborns. The most common long-term disability is sensorineural hearing loss (SNHL), which occurs in 10-15% of all cases. Infants with CACMV are also at increased risk for intellectual disability, cerebral palsy, learning disabilities, ocular and cortical blindness, seizure disorders, developmental delay, and autism spectrum disorders. Although infants with clinically inapparent cCMV (CICMV) are at risk for SNHL, the spectrum of other adverse neurodevelopmental outcomes is less clear, since few studies have tracked neurodevelopment in this setting. With the advent of universal cCMV screening, most cCMV infections will now be identified in infants with CICMV. These infants require serial audiologic monitoring, but many questions are unanswered, including what kinds of diagnostic evaluations are required; what kinds of central nervous system (CNS) imaging studies are recommended; what the utility and value of developmental assessments is; and whether there are biomarkers that can inform the long-term prognosis and direct anticipatory guidance in monitoring for neurologic and neurodevelopmental adverse outcomes. IMPACT: Universal newborn screening for congenital CMV (cCMV) infection has been implemented in many US states and Canadian provinces. Most infants identified by universal screening have CICMV infections. All require audiologic monitoring, but there is minimal experience to direct other evaluations, including laboratory tests, brain imaging and neurodevelopmental assessments. Adverse neurodevelopmental outcomes in CICMV may be more extensive than previously appreciated. Research is needed to define the full range of potential neurocognitive disability. New knowledge generated by studying CICMV infections may aid in reclassification of the scope of disease in an emerging era of universal cCMV screening.