An anti-mumps IgM antibody level in the serum of idiopathic sudden sensorineural hearing loss.

PURPOSE Measurement of anti-IgM antibody for mumps enables us to diagnose silent mumps infection. From the viewpoint of prophylactic medicine, we examined the incidence of silent mumps infection in idiopathic sudden sensorineural hearing loss (ISSNHL) by measurement of anti-mumps IgM antibody. MATERIALS AND METHODS Serum level of anti-mumps IgM antibody was evaluated by EIA method in 69 ISSNHL cases. RESULTS Of the 69 serum samples examined, five samples were positive, two samples were regarded as quasi-positive and other samples were negative for anti-mumps IgM antibody. The positive rate was 7.2% (5/69). The relationship of anti-mumps IgM and IgG antibody was also described. CONCLUSIONS From the measurement of anti-IgM antibody for mumps, it was possible to diagnose silent mumps infection in ISSNHL. The positive rate of anti-IgM antibody in ISSNHL was 7.2% suggesting that the silent mumps infection could be considered as one of the causative factors of ISSNHL even though its incidence is not so high. Since mumps often occurs without clinical symptoms, it is still considered to be one of the important causes of profound hearing loss. From the viewpoint of prophylaxis of profound hearing loss and deafness, we should understand the situation of virus epidemiology and vaccination.