不同疫苗覆盖场景下上海市和浙江省手足口病发病负担预测的动力学模型

目的 建立上海、浙江地区手足口病动力学模型，分析手足口病发展规律和流行情况，预测不同疫苗覆盖场景下疾病的变化趋势。方法 建立包含疫苗接种在内的8个仓室结构的系统动力学模型，运用2015-2017年手足口病发病数据对模型进行拟合，计算出基本再生数，并模拟不同疫苗覆盖情况下手足口病发病情况。结果 2015-2017年上海和浙江的基本再生数分别为：1.578、1.602、1.931和1.599、1.724、1.657。随着EV-A71疫苗接种率的上升，EV-A71所致手足口病的发病率呈现明显下降趋势；接种率达到80%时，EV-A71所致手足口病病例数将减少1/3左右。敏感性分析表明，未去医院就诊比例（P1）、疾病传播率（β）和未去医院就诊的康复率（γ1）对发病数的影响最大。结论 手足口病在上海和浙江地区人群中持续存在，EV-A71疫苗对于控制手足口病有一定的效果；由于EV-A71疫苗不具有其他肠道病毒交叉保护作用，应积极研发多价疫苗。

A dynamic model of hand,foot and mouth disease under different vaccine coverage conditions in Shanghai and Zhejiang Province

Objective To establish a dynamic model of hand,foot and mouth disease (HFMD) in Shanghai and Zhejiang Province,so as to analyze the epidemic condition of HFMD and to predict the impact of different vaccine coverages on the disease. Methods We built an 8-compartment dynamic model related to vaccination and used the incidence data of HFMD from 2015 to 2017 to fit the model.We also calculated the basic regeneration numbers,and simulated the incidence of HFMD under different vaccine coverage conditions. Results From 2015 to 2017,R₀ of Shanghai and Zhejiang Province were 1.578,1.602,1.931 and 1.599,1.724,1.657,respectively.With the increase of EV-A71 vaccine coverage,the incidence of HFMD caused by EV-A71 decreased gradually.When the vaccination rate reached 80%,the number of cases of HFMD caused by EV-A71 decreased by about 1/3.Sensitivity analysis showed that the parameters P₁ (proportion of infectious but not hospitalized),β (transmission rate) and γ₁ (recovery rate of infectious but not hospitalized) had the greatest effect on the number of cases. Conclusion HFMD will be prevalent constantly in Shanghai and Zhejiang Province.EV-A71 vaccine has a good effect on the control of HFMD.In addition,since the vaccine itself does not have the cross-protection effect of other pathogens,multivalent vaccines should be actively developed to improve the protection effectiveness.