Epidemic Characteristics Of Mumps And Its Trend Prediction In Changchun City During 2004-2016

Mumps is a class C infectious disease identified in China.It not only causes the enlargement of the parotid gland but also poses threat to the nervous system and reproductive system,resulting in serious sequelae.The disease could outbreak in schools and kindergartens,which would seriously affect the normal teaching order of the school.Thus,mumps is considered as one of the most important public health problems in children and adolescents health harm.In our country,the vaccination of gill wind vaccine has been carried out among the children of the right age,but there is no systematic review of the systematic assessment of the immune effect.Therefore,we should understand the characteristics and epidemic trend of mumps,and implement effective prevention measures through early warning to reduce the incidence and harmfulness of the disease,which is of great significance for reducing the impact of disease on people’s health.Objective:The study aims to understand the incidence and epidemic characteristics of mumps in Changchun,and to analyze the epidemic trend of mumps.So that we can establish the prediction model of mumps in Changchun,predict the incidence of mumps effectively and provide a scientific basis for prevention and control strategy.Methods:1.We used Mapinfo11.0 software to establish the annual average incidence map of 2004-2016 years,and dynamically displayed the spatial distribution characteristics of mumps in Changchun.We plotted the incidence curve of mumps,a pie chart of the occupation and a histogram of the age and gender,describing the characteristics of the time distribution and the distribution of the population.In the data processing,we used SPSS software to conduct the chi square test in order to analyse whether there was significant difference between males and females（α=0.05）.2.We established the time series using the monthly incidence of mumps from 2004 to 2016 years.The R software was used to establish the SARIMA model.According to the minimum value of AIC and the maximum principle of R²,the fitting effect of the model was evaluated,and the best model was selected.We confirm the validity of the model through tsdiag test.The selected SARIMA model was used to predict the incidence of mumps in Changchun in 2017.The root mean square error（RMSE）was used to compare the actual value with the theoretical fitting value,and the effectiveness of the model evaluation was evaluated.We also predict the incidence of mumps in 2018 using the selected model.Results:1.A total of 14342 cases of mumps were reported in Changchun in 2004-2016years,with an average annual incidence of 14.49/10 million.The peak of mumps in Changchun was concentrated in 2008-2009 years and 2011-2012 years.And the incidence of mumps had dropped to its lowest level in 2016.There were cases reported in all of the 10 counties and development zones in Changchun 10 counties and development zones,but there were significant differences between those counties.The high incidence areas were mainly concentrated in the main district and Shuangyang district.The morbidity of mumps was bimodal,which showed obvious seasonal distribution characteristics.The cases were mainly concentrated in students and children,the majority of whom were under 20 years old.The incidence of male was significantly higher than that of female,which was statistically significant by chi square test.2.The model SARIMA（0,1,3）（0,0,1）₁₂ was the best model for fitting the original sequence.The minimum goodness of fit index（AIC value）was868.34,the AICc value（adjusted AIC value）was 868.78,the BIC value was 883.16,which was the minimum value among all the effective models,and the R² value was0.447,which was the maximum value among all the effective models,so we could consider that the model fitting effect was good.Besides,the P value was less than0.05 so the model was of significance.We used the SARIMA（0,1,3）（0,0,1）₁₂ model to predict the incidence of mumps in 2017.By comparing the real values with the predicted values,the results of each month were within the range of 95%confidence limits,the average error was relatively small,and the prediction effect of the model was relatively ideal.3.The incidence of 2018 was forecasted by using the model.The results showed that the overall incidence increased slightly in 2018,but still at a low incidence level.Conclusion:1.The incidence of mumps in Changchun had obvious seasonal cyclical characteristics.There were two peaks of incidence every year,which were from March to May（the peak of spring）and from November to January next year（the peak of winter）.2.The incidence of mumps in Changchun is characterized by regional accumulation.The incidence is mainly concentrated in the central and southern parts of Changchun,especially in the new and high tech industrial development zones.3.The incidence of mumps in Changchun had obvious age difference.The incidence was mainly concentrated in children and adolescence under 20 years of age,and the incidence rate decreased with age.The incidence of male was significantly higher than that of female.4.The model SARIMA（0,1,3）（0,0,1）₁₂ established by our research had relatively ideal fitting parameters,and the prediction accuracy was pretty high,which could effectively predict the incidence trend of mumps in Changchun.