EPIDEMIOLOGY AND ETIOLOGY OF ACQUIRED HEARING DISORDERS IN CHILDHOOD IN THE COLOGNE AREA

Because of their serious consequences for all aspects of development, severe hearing disorders in children are an important clinical entity. A better understanding of the epidemiology and etiology of acquired h earing disorders may potentially lead to more effective prevention. Ma rked differences in the epidemiology of acquired hearing disorders are reported in the literature. In order to illuminate the problem of acq uired disorders and to define current etiological causes with special regard to ethnological factors in the Cologne area, we started a retro spective study. A total of 314 children in residence at the school for hearing impaired children in Cologne were investigated. We also obtai ned concise data on the structure of the population in order to determ ine prevalence of acquired hearing disorders in the German and immigra nt portions of the population. We found an overall prevalence of 0.43 parts per thousand for severe hearing disorders and deafness. German c hildren were most frequently affected by acquired, and non-German chil dren by hereditary hearing disorders. The most common causes of acquir ed severe hearing disorder were the perinatal complex of premature del ivery, anoxia and hyperbilirubinuria or kernicterus. Other causes were congenital rubella infections and meningitis in early childhood. The accumulation of perinatal etiologies seems to be the reason for the re markable majority of acquired hearing disorders among German children. One reason might be progress in neonatology which exerts two effects. It decreases perinatal mortality but increases perinatal complication s like acquired hearing impairment. The incidence of congenital rubell a in Germany has decreased during recent years, reaching a low level. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.