Sammendrag
Abstract
Objective: To assess prevalence, type and risk factors for hearing impairment in children in Nairobi slum areas.
Methods: Cross-sectional clinical study conducted in 2006 with complete clinical otological examination, tympanometry and pure-tone air-conduction audiometry assessment in children from four slum areas south east of Nairobi.
Results: Children between three and 15 years were included (N=152). Uni- or bilateral hearing loss above 25 dB HL was found in 21% (n=32) of the children; 8% (n=12) conductive and 13% (n=20) sensorineural. Bilateral hearing loss grade I or II was found in 8%(n=12). Earlier ear pain and ear discharge were reported by 11 of 12 children with conductive hearing loss. Prior to investigation 28% (n=43) had impacted cerumen. Positive and negative predictive value of subjective feeling of hearing loss was 56% and 89% when pure-tone air-conduction threshold of 26 dB HL was the gold standard. Corresponding values for ear discharge to differentiate between conductive and sensorineural hearing loss was 73% and 94%. Two children had atticus retraction, three ear drum perforation and nine children no tympanic mobility. In 75% (n=15) of the children with sensorineural hearing loss, high frequency pure-tone air-conduction threshold was above 25 dB HL at 8000 Hz. Hearing loss was significantly more common in slum areas with the best living conditions compared to lower living conditions, ORadj = 12.0 (95% confidence interval 3.8 to 37.7). The bivariate tendency that female gender and earlier hospitalization were risk factors for hearing loss did not remain significant after adjustment.
Conclusion: Hearing impairment, middle ear pathology and impacted cerumen was common in the Nairobi slum. The association between better living conditions and hearing loss may be due to ototoxic drugs or family clustering of sensorineural hearing loss.