Introduction: In 1994, a study was performed with 200 children and adolescents suffering from hearing loss. It concluded that the diagnostic confirmation of hearing loss within 2 years of age occurred in just 13% of the cases, although 56% were suspected in that phase. The loss of time of over 2 years between suspicion and confirmation of hearing loss occurred in 42% of the cases.
Objectives: The comparison of the main hearing loss etiologies-genetic cause, consanguinity, congenital rubella, meningitis, perinatal events and unknown causes-in children and adolescents in the periods of 1990-1994 and 1994-2000; comparison of incidence, in males and females, for each etiology and among the others; comparison of age at the first consultation, for each and among them; and the investigation as to whether the time between suspicion and diagnosis of hearing loss was different for each etiology and among the others.
Methods: During the period of 1990-2000, of the 519 children and adolescents with hearing loss, 442 individuals were selected, in the two moments of the study: 1990-1994 and 1994-2000. The variables used were: sex, age at first consultation, suspected etiology and time between suspicion and confirmation of hearing loss.
Results: Congenital rubella, genetic and perinatal causes, meningitis, consanguinity and unknown causes were responsible for over 80% of all etiologies, in both periods. There were no differences between the sexes in the periods studied. There was no relation among age, sex and etiology. Among the etiologies studied, there were no differences in the lengths of times between suspicion and confirmation of hearing loss, in each period separately. The comparative study showed that congenital rubella, genetic and unknown causes took longer times between suspicion and confirmation of hearing loss, for the period of 1990-1994, as compared with 1994-2000.
Conclusions: Congenital rubella remains as an important etiology, as well post-meningitis deafness. Age at first consultation did not show relationship to the hearing loss etiology nor to sex. Independently of whether the etiology being pre-natal, perinatal or post-natal, congenital or acquired, the length of time between suspicion and confirmation of hearing loss did not differ between the periods studied, separately.