Childhood hearing loss and risk profile in a South African population

Abstract

Objective: To describe the nature of hearing loss and associated risk profile in a representative South African population of infants and children diagnosed at a pediatric referral clinic. Methods:A retrospective review of patient files for a pediatric auditory evoked potential clinic in Pretoria was conducted (January 2007 to December 2011).Collected data included demographical information, risk factors from case history questionnaire, diagnosis (type and degree of hearing loss), documented age of caregiver suspicion and age of first diagnosis. Results:Hearing loss was present in 73% (73/100) of cases evaluated. Permanent hearing losses (SNHL, ANSD & Mixed) constituted 76% of losses. Unilateral hearing losses constituted 8% of SNHL and 20% of conductive hearing loss. ANSD was diagnosed in 21.4% and SNHL in 78.6% of permanent non-conductive hearing loss cases. The most prevalent SNHL risk was family history of hearing loss and for ANSD it was admittance to the NICU for more than 5 days. The majority of the sample was diagnosed with a permanent bilateral SNHL and ANSD after 36 months of age (47%) despite 40% already suspected of having a hearing loss before 12 months of age. Conclusions:A high prevalence of ANSD was found with preventable risk factors often indicated. Age of diagnosis was significantly delayed, evidencing the lack of early hearing detection services in South Africa. The majority of children were diagnosed at ages precluding optimal benefits from early detection and subsequent intervention.3

Profound childhood hearing loss in a South Africa cohort: Risk profile, diagnosis and age of intervention

“…Recently reported findings from Swanepoel et al [24] provide preliminary data on the nature of hearing loss and associated risk profiles for a small sample of infants with hearing loss in South Africa. However, data pertaining to additional developmental conditions and intervention was not available for this sample population.…”

“…As a result, the average age of hearing loss diagnosis in South Africa has been reported to be between 23 to 44.5 months [23][24][25], in contrast to the recommended age of 3 months [26].…”

“…As a result of limited early hearing detection and intervention (EHDI) programs and poor data capturing and management amongst existing programs [20,24] the prevalence and nature of PCEHL in South Africa is largely unknown along with the associated risk profiles. Except for a series of etiological surveys of children in schools for the deaf dating back to the 1970s and early 80s [28], no data has been available to describe the risk profile of PCEHL in South Africa.…”

“…This was not accounted for in these early South African reports [28][29][30]. Only in a recent report was the nature of hearing loss and associated risk profile described with consideration of ANSD for a population of infants and children diagnosed at a pediatric referral clinic in South Africa [24]. More than half of the diagnosed children (56%) presented with sensorineural hearing loss, with 50% being of a profound degree.…”

Does parental experience of the diagnosis and intervention process differ for children with auditory neuropathy?

“…Waiting for the child to be old enough for these behavioral assessments, prolong the process, as reported by the parents in this study. Since a significant proportion of children with permanent hearing loss have ANSD, with estimates between 10% and 20% [5,21] audiological diagnosis should rely on appropriate test batteries to accurately determine ANSD as soon as possible [5]. Following recommended guidelines such as those developed at the ANSD consensus conference may facilitate more consistency across practices [4,16].…”