Analysis On Transmission Dynamics Mechanism And Immune Strategry Of Hand-Foot-Mouth Disease

Hand,foot and mouth disease?HFMD?is an infectious disease caused by enterovirus.There are more than 20 kinds of enteroviruses causing hand,foot and mouth disease,including Coxsackievirus A16?Cox A16?and Enterovirus 71?EV 71?.This disease mainly infects children under 5 years of age,showing mouth pain,anorexia,low fever,small herpes or small ulcers in the hands,feet,mouth and other parts.Most children can be self-healing,but a small number of children may cause myocarditis,pulmonary edema,sterility Complications such as meningoencephalitis.Some of them with severe illness develop rapidly and would lead to death.The monomer vaccine for HFMD was successfully developed in China in December 2015 and officially launched in the first half of 2016.But,due to the self-funded vaccine and the lack of comprehensive evaluation of the vaccine,as well as low vaccination rate,the prevention and control are still an important work.The main contents of this paper are presented as follows.Firstly,we introduce the background and the significance of HFMD transmission dynamics,and summarize the current research status.We further present the basic knowledge of epidemic models and the main results of current HFMD dynamics models.Secondly,in order to further reveal the transmission mechanism and optimize immune strategy of HFMD,we proposes a new HFMD transmission model,which incorporates the effects of age structure,contact patterns and vaccination.We first use next generation matrix to calculate the basic reproduction number,and then use the theory of stability and dynamics to prove the existence and stability of the disease-free and endemic equilibria.We finally use numerical simulation to explore the effects of model parameters.It is found that age structure,contact matrix and vaccination have significant influence on the transmission,in which the heterogeneity of age structure may worsen the infection,but quarantining patients,improving vaccination coverage and vaccination rates can effectively help to control the disease.The results can provide scientific reference for the prevention and control of HFMD transmission.Thirdly,we develop a two-age structure model with"consciousness factor"to accounting for the reduction of contact rate due to awareness of infection.We first analyze the basic reproduction number R₀ by the knowledge of the next generation matrix.We then prove that when R₀<1,the disease will eventually disappear.while R₀>1,The disappear will always exist and the number of infected people will eventually become stable over time.Public awareness to the disease can reduce the infection size.Finally,we summarize the main results and the direction for future research.The obtained results can be used as a reference for the analysis of epidemic models and further for disease control.