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.