Feasibility of establishing an infant hearing screening program and measuring hearing loss among infants at a regional referral hospital in south western Uganda

Introduction
Despite the high burden of hearing loss (HL) globaly, most countries in resource limited settings lack infant hearing screening programs(IHS) for early HL detection. We examined the feasibility of establishing an IHS program in this setting, and in this pilot program measured the prevalence of infant hearing loss (IHL) and described the characteristics of the infants with HL.

Methods
We assessed feasibility of establishing an IHS program at a regional referral hospital in south-western Uganda. We recruited infants aged 1 day to 3 months and performed a three-staged screening. At stage 1, we used Transient Evoked Oto-acoustic Emissions (TEOAEs), at stage 2 we repeated TEOAEs for infants who failed TEOAEs at stage 1 and at stage 3, we conducted Automated brainstem responses(ABRs) for those who failed stage 2. IHL was present if they failed an ABR at 35dBHL.

Results
We screened 401 infants, mean age was 7.2 days (SD = 7.1). 74.6% (299 of 401) passed stage 1, the rest (25.4% or 102 of 401) were referred for stage 2. Of those referred (n = 102), only 34.3% (35 of 102) returned for stage 2 screening. About 14.3% (5/35) failed the repeat TEOAEs in at least one ear. At stage 3, 80% (4 of 5) failed the ABR screening in at least one ear, while 25% (n = 1) failed the test bilaterally. Among the 334 infants that completed the staged screening, the prevalence of IHL was 4/334 or 12 per 1000. Risk factors to IHL were Newborn Special Care Unit (NSCU) admission, gentamycin or oxygen therapy and prematurity.

Conclusions
IHS program establishment in a resource limited setting is feasible. Preliminary data indicate a high prevalence of IHL. Targeted screening of infants at high risk may be a more realistic and sustainable initial step towards establishing IHS program s in a developing country like Uganda.

Evaluation of Portable Tablet-Based Audiometry in a South Indian Population

While a comprehensive booth audiogram is the gold standard for diagnosis of hearing loss, access to this may not be available in remote and low resource settings. The aims of this study were to validate a tablet-based audiometer in a tertiary medical center in India and explore its capacity in improving access to hearing healthcare. Subjects presenting to Ear–Nose–Throat clinics for conventional booth audiometry testing were recruited for subsequent tablet-based audiometric testing. Testing with the tablet was conducted in a non-sound-treated hospital clinic room. Bilateral air and bone conduction hearing threshold data from 250 through 4000 Hz were validated against conventional booth audiometry. In addition, a small feasibility study was conducted in rural clinics. 70 participants (37 adults and 33 children between the ages 5–18) were assessed. 69% were male, with a mean age of 29.7 years. Sensitivity and specificity for the tablet were 89% (95% CI 80–94%) and 70% (95% CI 56–82%), respectively. While median differences in air conduction thresholds between conventional and tablet audiograms showed statistical significance at 250, 500, and 1000 Hz (p < 0.001), the threshold results of the tablet audiometer were within 5 dB of the conventional audiogram and not clinically significant. Ten patients were successfully screened in rural clinics with tablet audiometry. Tablet portable audiometry is a valid tool for air and bone conduction threshold assessment outside of conventional sound booths. It can accurately identify hearing impairment and offers a screening tool for hearing loss in low resource settings.