Establishment Of Dynamic Models And Data Simulation For Hand, Foot And Mouth Disease In Jiangsu Province

?Objective? To establish two dynamic models of hand foot and mouth disease in Jiangsu province,namely the models of hand,foot and mouth disease based on the whole population in Jiangsu Province and that based on children under 5 years old in Jiangsu Province.The basic reproductive numbers R₀ of hand,foot and mouth disease in the whole population and children under 5 years old in Jiangsu Province were obtained by data simulation,thereby we could know the prevalence of hand,foot and mouth disease in Jiangsu Province and predict the incidence trend.On this basis,EV71 vaccination was included in the model to simulate the number of hand,foot and mouth disease cases under different vaccination coverage rates,and provide evidence for the immunization strategy of EV71 vaccine in the future.?Methods?We constructed two compartmental model of hand foot and mouth disease,establish a group of differential equations.The incidence data of hand foot and mouth disease in the whole population and children under 5 years of age in Jiangsu was used to fit the model and calculate the basic reproduction number of this disease in this two population.Then,we added vaccination in the model and simulated the incidence of hand foot and mouth disease under different vaccination coverage rates.?Results? The median basic reproduction numbers of hand foot and mouth disease in Jiangsu between 2013 and 2016 simulated by the model based on the whole population in Jiangsu are 1.31?IQR:0.99-1.48?,1.37?IQR:0.97-1.52?,1.34?IQR:1.00-1.61?and 1.38?IQR:1.00-1.76?,respectively.According to the number of hand,foot and mouth disease cases in the whole population in Jiangsu Province from 2013 to 2014,the predicted number of hand,foot and mouth disease cases in the whole population in Jiangsu Province from 2015 to 2016 is relatively consistent with the actual number of cases,and the trend is roughly the same,but the estimated peak number of cases is slightly below the actual number of cases.Sensitivity analysis showed that after adjusting the initial susceptible individuals S?0?,the overall fluctuation range of predicted numbers was small.The fluctuation range of peak number of cases in 2016 was slightly larger than that in 2015,but it did not have a significant impact on the predicted trend.With the increase of immunization coverage of EV71 vaccine,the cases of hand foot and mouth disease caused by EV71 will decrease accordingly.When the annual immunization rate of EV71 vaccine is maintained at a high level?75%?,the annual incidence of hand foot and mouth disease caused by EV71 after 5 years will reduce to 10% of that in the same year when there is no vaccination.The median basic reproduction numbers of hand foot and mouth disease in children under 5 years of age in Jiangsu between 2013 and 2016 simulated by the model based on children under 5 years of age in Jiangsu are 1.23?IQR:0.90-1.38?,1.28?IQR:0.88-1.47?,1.25?IQR:0.91-1.52?and 1.30?IQR:0.80-1.65?,respectively.Under this model,the predicted trend is similar to the actual trend,but the predicted curve of hand foot and mouth disease cases is more volatile than the actual curve.In addition,the sensitivity analysis showed that the number of initial susceptible individuals S?0?had a great impact on the predictive effect of the hand,foot and mouth disease dynamic model based on children under 5 years old in Jiangsu Province.After S?0?was adjusted up or down,the number of predicted cases has changed greatly.The predicted difference at the beginning of 2015 was small.As time goes by,the predicted difference gradually became larger.In 2016,the predicted difference at peak incidence is larger,with a maximum difference of 6000 cases.?Conclusions? The model based on the whole population in Jiangsu is more stable,which is suitable for predicting the prevalence trend of hand foot and mouth disease caused by EV71 and the effect of vaccination.The epidemic trend of hand foot and mouth disease in Jiangsu is stable from 2013 to 2016.Vaccination plays an important role in controlling hand foot and mouth disease caused by EV71.