Transmission Dynamics For Brucellosis Model And Theoretical Analysis

Brucellosis is a contagious bacterial disease of animals and humans caused by membersof the genus Brucella. Clinical features mainly are pregnant female abortion, infertility,orchitis, liver and spleen enlargement. The livestock economic losses caused by brucellosisare more than1billion RMB and the number of newly infected human brucellosis is about40,000people annually. So seeking the prevention and control measures of brucellosis areparticularly important, and through analyzing the dynamic model, we can obtain the trend ofbrucellosis and the optimal strategy for prevention and control. However, nowadays fewliteratures make use of the dynamical model to study brucellosis. In order to find out the keyfactors in the process of the spread of brucellosis and explore effective control and preventionmeasures, this paper makes the following researches:In chapter1, we give the significance of investigating brucellosis, development of thisfiled and the main work in this thesis.In chapter2, we investigate a sheep brucellosis dynamic model with stage structure. Thebasic reproduction number and the unique positive equilibrium of this model are obtained. Byconstructing Lyapunov functions, the global stability of the equilibrium is proved. Finally, weperform a series of numerical simulations to confirm the theoretical analysis.In chapter3, we present a multi-group brucellosis model with mixed cross infectionbetween cattle and sheep in public farm. We obtain the expression of the basic reproductionnumber, confirm the uniform existence and unique positive equilibrium of dynamic modeland prove the global stability of the disease-free equilibrium and the endemic equilibrium.We use four examples to show the influence of the infectious herds with existing mixed crossinfection between cattle and sheep or not. Finally, we conclude that mixed cross infectionbetween cattle and sheep is a very important factor for brucellosis transmission. So cutting mixed cross infection between cattle and sheep is necessary to control brucellosis, which isonly needed to separate cattle and sheep feeding in the real world.In chapter4, we study a brucellosis dynamic model between human and sheep inHinggan League of Inner Mongolia, China. The model describes the spread of brucellosisamong sheep and from sheep to humans. Through the analysis of the dynamics model, thebasic reproduction number, the global asymptotic stability of the disease-free equilibrium, theuniform existence and global asymptotic stability of positive equilibrium with this model aregiven. Combining with the newly infected human brucellosis data annually, this paper takesthe model to simulate the data and predict that the number of the newly infected humanbrucellosis. We also give the basic reproduction number is about1.9789for the brucellosistransmission in Hinggan League. According to the sensitivity and uncertainty analysis of thebasic reproduction number, we conclude that vaccination, detection and prohibiting mixedfeeding between basic ewes and other sheep are the key factors for controlling brucellosis inHinggan League of Inner Mongolia, China.