Dynamics of Trachoma Epidemic in Human Contact Network with Seasonally Varying Infectious Medium

The transmission of infectious diseases excessively depends on the seasonality variation of the infective mediums. Infectious diseases may be contagious, vector borne, air or water borne. In this paper, we had investigated the epidemic model of a vector-borne disease (Trachoma), which is contagious as well. For this purpose, we extended the SIS model and examined the impact of seasonal variations in the dynamics of the disease spreading model. Seasonal variations are periodically occurring short-term fluctuations. Some of the causes of seasonality comprise the competence of the pathogen to survive outside the host. This relies upon several factors like temperature, sunlight, rainfall, humidity, immunity of the host and abundance of the vectors. Here we extend the mathematical model of trachoma transmission over human contact networks and studied how the disease transmission occurs in the contact networks with seasonally varying infectious medium. For this purpose, we considered mathematical SIS epidemic with homogeneous contact and heterogeneous contact networks. In both contact networks, basic reproduction number R_0 is derived and equilibrium analysis is also discussed. Finally, the numerical results are illustrated to corroborate the theoretical findings.