From Silent Threat to Early Intervention: Evaluating the Universal Hearing Screening Program in Infants at a Primary Health Facility in Zambia--A Prospective Cohort Study.

Introduction: Successful implementation of universal hearing screening has been shown to be an effective strategy for minimizing the negative impact of hearing loss in childhood. However, data on prevalence and risk of hearing loss among neonates and infants in Zambia remain underreported, thus negatively affecting government obligations to provide equitable resources and focus to hearing health care programs. The aim of the study was to assess the feasibility of implementing a universal hearing screening program using otoacoustic emissions and contextualize risk factors appropriate for a successful hearing screening program in Zambia. Method: This planned substudy of a prospective birth cohort employed a quantitative, longitudinal repeated-measures design. Data on risk factors for hearing loss were collected using a semistructured questionnaire. Other data variables for risk factors of hearing loss such as maternal COVID-19, HIV status, cyto-megalovirus, and syphilis were collected from the parent study. Distortion product otoacoustic emission (DPOAE) screenings were conducted at two time points, 6 days after birth and at 6 months after birth. Participants who did not pass the second DPOAE hearing screening were referred for further diagnostic audiological assessment. Data were analyzed using descriptive statistics. We also performed chi-square and Fisher's exact tests. Results: Over the course of 6 months, a total of 678 of 726 (93%) infants born into the cohort were screened for hearing loss. Of the nine infants referred for further diagnostic testing, three were lost to follow-up and six underwent either tympanometry or auditory brain response testing. Most tympanometry findings were type B, which is associated with abnormal otoscopic findings. From these six, one was diagnosed with mild-to-moderate hearing loss using the auditory steady-state response test. Thus, the incidence of hearing loss was 1.5 per 1,000 live births. There was no association between low birth weight, prematurity, neonatal jaundice, and corresponding DPOAEs results.