الفهرس 
Chapter 1 IntroductionOnly 14 pages are availabe for public view
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Abstract
My thesis is concerned with periodic mathematical models for the spread of two different mosquito-borne diseases and a rodent-borne disease. In particular, it presents compartmental population models for the transmission dynamics of malaria, Zika virus and Lassa virus diseases in a seasonal environment. The main aim of the thesis was to investigate the impact of the periodicity of weather on the spread of the above-mentioned diseases by applying non-autonomous mathematical models with time-dependent parameters. The basic reproduction number R0 is defined as the spectral radius of a linear integral operator and the global dynamics is determined by this threshold parameter. We show the global stability of the disease-free periodic solution and the extinction of the disease if R0<1, as well as the persistence of the disease in the population and there exist at least a positive $\omega$-periodic solution when R0 > 1. Numerical simulations to illustrate and support the analytical results are given.