Aetiology of childhood hearing loss in Cameroon (sub-Saharan Africa).

Background: Severe hearing loss is a global problem affecting particularly developing countries. There is scarcity of recent published data on the epidemiology of childhood deafness in sub-Saharan Africa.

Objective: To determine the etiological profile of severe childhood deafness in Cameroon.

Methods: Prospective cross-sectional study of patients with a severe hearing loss that started before the age of 15 years. Detailed family and medical history was obtained; careful clinical, otological and audiological examinations were performed.

Results: A total of 582 patients with a severe hearing loss were examined. Prelingual deafness accounted for 75.1% (n = 437), with a mean age at medical diagnosis of 3.3 ± 1.2 years. This late presentation may be explained by limited parental awareness of signs raising suspicion of hearing loss, poor access to health care and the absence of neonatal screening for hearing loss in Cameroon. Identified genetic causes accounted for 14.8% (n = 86), putative environmental causes for 52.6% (n = 306) and unknown causes for 32.6% (n = 190). Amongst Genetic causes, the syndromic hearing loss accounted for 13.1% (n = 12) of cases, the rest being non syndromic (n = 74). Consanguineous families accounted for 5.7% (n = 33) of the whole sample, and 15.1% (n = 13) of genetic cases. No union between deaf parents was observed.

Conclusion: These data highlight the possible predominance of putative environmental causes of childhood deafness in Cameroon, and emphasize the need for improved policies for prevention of infectious diseases and for neonatal hearing screening. However, further molecular analyses and targeted CT scan investigations are required to more accurately gauge the contribution of genetics etiologies.