Newborn hearing screening in a developing country: results of a pilot study in Abidjan, Côte d'ivoire.

OBJECTIVE: To investigate the feasibility of neonatal hearing impairment in newborn babies in Abidjan, Côte d'Ivoire.
METHODS: It is a cross-sectional study in which all infants aged from 3 to 28 days, attending for Bacille Calmette-Guerin (BCG) immunization in primary care centers or hospitalized in neonatal intensive care units (NICU), between July 2007 and March 2008, were included. Screening followed a two-stage strategy with transient evoked otoacoustic emissions (TEOAE). Infants referred after the second-stage screening were scheduled for diagnostic evaluation by diagnostic auditory brainstem response (ABR). The variables analyzed were: screening coverage, referral rates; return rates for second-stage screening and diagnostic evaluation, incidence of permanent hearing loss and age at diagnosis.
RESULTS: 1306 newborns, of a total of 1495, were successfully screened, giving a screening coverage of 87.4%. The average age was 4.5 days (S.D.: 2.7), with 5.85 days (S.D.: 3.17) for the immunization group and 3.20 days (S.D.: 0.40) for the neonatal unit group. In total, 286 out of the 1306 infants (21.9%) were referred after the first-stage screening; out of which 193 (67.5%) return for the second stage. After the second-stage screening, 48 (16.8%) were scheduled for diagnostic evaluation (45 from NICU and 3 from primary care centers). The overall referral rate for diagnostic evaluation was 3.7% (48/1306). Only 18.75% of those referred (9/48) returned for evaluation, and seven of them (77.8%) were confirmed with hearing loss (2 from immunization group and 5 from neonatal unit group). The prevalence of permanent hearing loss in this screened population was 5.96 per 1000 (7/1174 babies who completed the screening) [95% I.C.: 5.62-6.30 per 1000]. The mean age at diagnosis was 22 weeks (S.D.: 8.3). The reasons for non-completed screening were, according to 62 mothers: no financial means, absence of hearing loss, fear of spouse reactions, lack of information about this test and deafness.
CONCLUSION: The incidence of permanent and early hearing impairment identified by this screening program was about 6 per 1000. Routine hearing screening of infants for the early detection of hearing loss is necessary in Côte d'Ivoire. It is possible to implement such a hearing screening, targeting all newborns, in primary health care centers and neonatal intensive care units. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.