Comparative Study of Mumps Serology in SNHL Children and Unaffected Ones

Mumps infection is endemic in Iran. Due to high percentage of unvaccinated young people(<15yr old) in Iran, the incidence rate of mumps infection and its sequeles are probably higher in comparison with its incidence in developed countries before massive vaccination. The goal of the present study was to determine the role of mumps infection in children with sensory neural hearing loss. Patients & This descriptive cross-sectional study was conducted on 87 children aged up to 14 years with SNHL and 30 controls in the pediatric and ENT ward of Hazrat Rasool Hospital in Tehran from 2002-2003. The blood samples of these patients were tested for specific antibody(IgM&IgG) for mumps by Elisa method. The mean age was 39.8+27.9 months(male: 60.6% and female 39.4%). The highest incidence of age was 3-5 years(51.5%) and the lowest one was>10y(2.1%). Acute mumps infection(positive IgM) was seen in 8.3% and previous immunity to mumps(IgG) in 24.1% of all. The highest incidence of acute infection(IgM) was in 3-5-year old group, but it was not different in other age groups(P=0.11). Previous infection(IgG was also higher in 3-5-year old group and it was significantly different in other age groups(P=0.05). Acute(IgM) and previous infection(IgG), except in mean age of children(P=0.015, 0.013), was not significantly differente in terms of sex in case and control groups(P=1 0.4). Seventy-five percent of all children had no immunity to mumps infection. Twenty-four percent of SNLH patients(like other healthy children) had immunity to mumps infection. Acute mumps infection was seen in 8.8% of 3-5-year-old children of case compared to 6.8% of control group(P=0.11) However, previous immunity in case was lower than control group(P=0.4). Mumps infection in SNLH children aged between 3-5-year-old is more common and important than other age groups. Since the risk of SNHL after mumps infection will increase in older age, prevention of mumps by inexpensive and very effective mumps vaccine is helpful. Thereby, the costs of mumps infection and its sequles can be decreased with massive vaccination of Iranian young people (<20 years old). 3) Mumps Vaccination/