Background: The burden of congenital cytomegalovirus (CMV)-associated sensorineural hearing loss (SNHL) in populations with CMV seroprevalence approaching 100% is unknown. The purpose of this study was to assess the rate, associated factors, and predictors of SNHL in CMV-infected infants identified by newborn screening in a highly seropositive maternal population.
Methods: Newborns with positive saliva CMV-DNA that was confirmed by virus isolation in the first 2 weeks of life were enrolled in a prospective follow-up study to monitor hearing outcome.
Results: Of 12,195 infants screened, 121 (1%) were infected with CMV and 12 (10%) had symptomatic infection at birth. Hearing function could be assessed in 102/121 children who underwent at least one auditory brainstem evoked response testing at a median age of 12 months. SNHL was observed in 10/102 (9.8%; 95% confidence interval: 5.1–16.7) children. Median age at the latest hearing evaluation was 47 months (12–84 months). Profound loss (>90 dB) was found in 4/5 children with bilateral SNHL while all 5 children with unilateral loss had moderate to severe deficit. The presence of symptomatic infection at birth (odds ratio, 38.1; 95% confidence interval: 1.6–916.7) was independently associated with SNHL after adjusting for intrauterine growth restriction, gestational age, gravidity, and maternal age. Among 10 infants with SNHL, 6 (60%) were born to mothers with nonprimary CMV infection.
Conclusions: Even in populations with near universal immunity to CMV, congenital CMV infection is a significant cause of SNHL demonstrating the importance of CMV as a major cause of SNHL in children worldwide. As in other populations, SNHL is more frequently observed in symptomatic CMV infection.
From the *Faculty of Medicine of Ribeirão Preto, Department of Pediatrics, University of São Paulo, São Paulo, Brazil; †Faculty of Medicine of Ribeirão Preto, Department of Ophtalmology, Otorrinolaringology, and Head and Neck Surgery, University of São Paulo, São Paulo, Brazil; ‡Department of Pediatrics, University of Alabama School of Medicine, Birmingham, AL; §Department of Microbiology, University of Alabama School of Medicine, Birmingham, AL; and ¶Department of Neurobiology, University of Alabama School of Medicine, Birmingham, AL.
Accepted for publication July 13, 2011.
Supported by grants from the National Institutes of Health (NIAID AI 49537; Fogarty International Center, R03 TW006480 to WJB), (NIDCD DC04162 to SBB), and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Brazil, Process number 02/04166-6.
The authors have no other funding or conflicts of interest to disclose.
Address for correspondence: Aparecida Yulie Yamamoto, MD, Departamento de Pediatria da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, Avenida Bandeirantes 3900, Campus da USP-CEP: 14049-900, Ribeirão Preto, São Paulo, Brazil. E-mail: firstname.lastname@example.org.