We experienced 3 cases (7 to 9 years old) who presented with sudden deafness after the onset of parotid swelling during a period from February to May in 1994. All patients have not received immunization, and unilateral sensorineural deafness was not improved in spite of the treatment.
In Hachinohe area mumps has been epidemic from November, 1993 and about 10% of children in Hachinohe city suffered mumps. So the incidence of mumps deafness was presumed to be at least 0.005%.
Most of the patients with mumps were under 4 years of age. So, the complaint of deafness was obscure to make diagnosis in some cases, which posed a problem.
In order to prevent mumps deafness, the positive measures including vaccination should be taken.