objective To estimate the prevalence and causes of hearing impairment in Fundong Health District,
North-West Cameroon.
methods We selected 51 clusters of 80 people (all ages) through probability proportionate to size
sampling. Initial hearing screening was undertaken through an otoacoustic emission (OAE) test.
Participants aged 4+ years who failed this test in both ears or for whom an OAE reading could not
be taken underwent a manual pure-tone audiometry (PTA) screening. Cases of hearing impairment
were defined as those with pure-tone average ≥41 dBHL in adults and ≥35 dBHL in children in the
better ear, or children under age 4 who failed the OAE test in both ears. Each case with hearing loss
was examined by an ear, nose and throat nurse who indicated the main likely cause.
results We examined 3567 (86.9%) of 4104 eligible people. The overall prevalence of hearing
impairment was 3.6% (95% confidence interval [CI]: 2.8–4.6). The prevalence was low in people
aged 0–17 (1.1%, 0.7–1.8%) and 18–49 (1.1%, 0.5–2.6%) and then rose sharply in people aged 50+
(14.8%, 11.7–19.1%). Among cases, the majority were classified as moderate (76%), followed by
severe (15%) and profound (9%). More than one-third of cases of hearing impairment were classified
as unknown (37%) or conductive (37%) causes, while sensorineural causes were less common (26%).
conclusions Prevalence of hearing impairment in North-West Cameroon is in line with the WHO
estimate for sub-Saharan Africa. The majority of cases with known causes are treatable, with
impacted wax playing a major role.