Investigation on an outbreak of mumps in kindergarten

[Objective]To investigate the epidemic characteristics of an outbreak of mumps and the protective effect of the vaccine on mumps.[Methods]Mumps cases were searched according to the diagnosis criteria of mumps to describe the epidemic situation,and the vaccination information of children were collected.The vaccine protection efficiency(VE) was calculated by this formula: VE(%) =(incidence rate of unvaccinated group-incidence rate of vaccinated group) / incidence rate of unvaccinated group × 100% =(1-RR) × 100%.[Results]A total of 126 cases were searched,and the attack rate was 11.42%(126 /1 103).Among 22 classes in the kindergarten,the cases were reported in 16 classes.The attack rate of unvaccinated children was 27.47%(64/233),and that of vaccinated children was 10.78%(56/519),with VE of 61%.Vaccine protective efficacy showed a decreasing trend with time interval of once vaccination.[Conclusion]Mumps vaccine is a protective factor of mumps.The vaccine protective efficacy shows a decreasing trend with time interval,so it is recommended that an additional dose of vaccine should be carried out three years after first dose mumps vaccination.