MOPE076 - Poster Exhibition
Hearing impairment in HIV-infected children in Tanzania
I. Maro1,2, N. Moshi2, E. Richard2, A. Fellows3, O. Clavier4, J. Wilbur4, R. Chambers4, B. Jastrzembski5, J. Gui3, M. Bakari2, C.F. von Reyn3, P. Palumbo3, J. Buckey3
1DarDar Health Study, Dar es Salaam, Tanzania, United Republic of, 2Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania, United Republic of, 3Geisel School of Medicine at Dartmouth, Hanover, United States, 4Creare Inc, Hanover, United States, 5Harvard Medical School, Boston, United States
Background: Abnormal hearing tests have been noted in HIV-infected children in several studies, but the exact nature of the hearing deficit is unknown. We performed a cross-sectional study of audiological parameters from a cohort of HIV-infected and HIV-uninfected children in Tanzania.
Methods: Pure-tone thresholds, distortion product otoacoustic emissions (DPOAEs), tympanometry and a either a gap detection test or auditory brainstem responses (ABR) were performed using a laptop-based hearing testing system on 242 children (134 HIV+, 108 HIV-, average age 10 years) in Dar es Salaam Tanzania. Subjects completed a video questionnaire about their hearing and a health history questionnaire. Only 26 of the HIV+ children were not on anti-retroviral therapy (ART).
Results: Hearing thresholds did not differ significantly between the HIV+ and HIV- groups. DPOAEs, a test for outer hair cell function of the inner ear, were significantly lower in the HIV+ group at multiple frequencies (3000Hz (p=0.008), 4000Hz (p< 0.003), 6000Hz (p < 0.001), and 8000Hz (p< 0.001)) compared to the HIV- group. The HIV+ group also had significant more children who reported a history of draining ears (p< 0.004), had abnormal tympanograms (p< 0.04), and reported a history of dizziness or imbalance (p=0.002). When the DPOAE values were adjusted using logistic regression to compensate for the confounders of ear drainage and abnormal tympanograms, the DPOAEs were only significantly different at 6000 and 8000 Hz. No differences were seen in the gap detection and ABR measures. Within the HIV+ group, however, those on nevirapine containing regimens showed improved gap detection at 4 msec (p< 0.03 Mann-Whitney U test) compared to those not on nevirapine.
Conclusions: HIV-infected children show reduced high frequency DPOAEs compared to HIV-negative individuals, but most of the differences in hearing can be explained by middle ear pathology. Gap detection results (a measure of central auditory function) show a tendency for improved function on nevirapine-containing regimens. Further data collection and analysis are needed to confirm these findings.
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