RESUMEN
In the last years, according to the increasing incidence of measles and other viral diseases, it have been needed to study on not only the fundamental epidemiological characteristics of mumps and measles but also judgement on the effectiveness of vaccine that meet our domestic situation. The author carried out questionnaire to obtain epidemiological characteristics and vaccine efficacy of mumps on epidemics of mumps in one primary school in Hwasung-kun, Kyonggi Do from Feb. to July, 1994. The results are summarized as follows: 1. Total students was 556, but 446(78.4%) responded to the questionnaire. Among that 446,130(29. 1%) have suffered from mumps. From 9 to 10 year old students had the high attack rates, especially 10 year olds has the highest(39. 7%). 2. From Feb. 2, 1994, first case was on, to July 6, 1994, the epidemic was continues, and attack rate was higest in May(50. 5%). 3. Among the 130 mumps patients, 5 have suffered from complication(3.8%) : encephalitis 3(2 in male, 1 in female). 4. Vaccination rate was 91%, and as ages were lowered, the rates were higher. 5. Attack rate was higher in group who had time interval after vaccination less than 5 years than total attack rate, and was higher in group who had been vaccined after 5 year old. 6. Attack rate in vaccinated group was 27.3%. 7. Vaccine efficacies, be judged by three methods of analysis according to case definition and vaccination status, were 37.4 39. 2%. 8. Factors that have significantly affected the mumps epidemic were vaccination status and vaccination age.