Objektive Audiometrie und klinische Anwendung

Community health workers obtain similar results using cell-phone based hearing screening tools compared to otolaryngologists in low resourced settings

OBJECTIVE

To establish community health workers as reliable hearing screening operators in a technology-based pre-surgical hearing screening program in a low and middle-income country (LMIC).

METHODS

This is a cross sectional study that evaluated community health worker driven hearing screening that took place in semi-rural Malindi, Kenya during an annual two-week otolaryngology surgical training mission in October 2017. At five separate locations (four schools) near Malindi, Kenya, children between the ages of 2-16 underwent hearing screening using screening audiometry (Android-based HearX Group). Children were screened by a community health worker who underwent a short training course, a senior otolaryngology resident, or both. Hearing screening results were compared to determine the reliability and concordance between independent, blinded community health worker and otolaryngology resident testing.

RESULTS

One hundred and four participants (53% males) underwent hearing screening. Hearing screening pass rate was 93%. Community health workers obtained a similar result to otolaryngology residents 96% of the time (McNemar test: p = 0.16, OR 0.96, 95% CI 0.9-1.0).

CONCLUSION

Community health workers can obtain reliable results using a technology-based, pre-surgical hearing screening platform when compared to otolaryngology residents. This finding has profound implications in low-resourced settings where hearing healthcare specialists (audiologists and otolaryngologists) are limited and can ultimately improve the surgical yield of patients presenting to local otolaryngologists in these settings.

Phenotypic Characterization of DFNB16-associated Hearing Loss

HYPOTHESIS

We hypothesized that patients with DFNB16 caused hearing loss show characteristical audiological findings depending on genetic results.

BACKGROUND

Hearing loss belongs to the most frequent congenital diseases. In 50-70% of individuals, hearing loss is caused by genetic defects. DFNB1 (deafness, neurosensory, autosomal-recessive) is the most frequently affected locus. Despite its great genetic heterogeneity, comprehensive analysis of genes like STRC, encoding stereocilin (DFNB16) is possible. The genetic architecture of the DFNB16 locus is challenging and requires a unique molecular genetic testing assay. The aim of the study is a systematic characterization of the audiological phenotype in DFNB16-positive patients.

METHODS

Since 2011, 290 patients with suspicion of inherited hearing loss received a human genetic exploration. Eighty two DFNB1-negative patients advanced to further testing in the DFNB16 locus. STRC-positive patients obtained complete audiological diagnostic workup. Additionally, epidemiological data was collected.

RESULTS

Nine of 82 (11%) of the examined patients (mean age 5 yr) showed mutations in the STRC (3 homozygous, 6 compound heterozygous). Aside from a moderate hearing loss in the pure tone audiogram, auditory brainstem response thresholds were 40-50 dB nHL. Otoacoustic emissions were detectable in only one patient.

CONCLUSIONS

Examination of the DFNB16-locus should be a standard diagnostic test after negative DFNB1-gene screening result. Notably, DFNB16-associated hearing loss can be audiologically characterized as moderate sensorineural hearing loss in the main speech field with absent otoacoustic emissions. Our study is the first to correlate audiological findings with genetic results in patients with hearing loss due to STRC.