In this paper we propose a method of mathematical modeling of the epidemiological situation, taking into account external factors. An algorithm for finding the parameters of the model based on the results of observations, based on the method of least squares. Investigated the dependence of the epidemiological situation of the various parameters and external factors, as well as the ability to manage the development of epidemics by influencing these factors. Proposed the concept of the system of monitoring the epidemic situation, taking into account the external risks.
A calculation method and a variation method of parameters of the epidemic situation model taking into account external risks is proposed. The detailed step-by-step algorithm available in the application EXCEL for the calculation and analysis of the model parameters based on the results of observations is given. The prognosis of the epidemic situation with the estimation of the disease outbreak duration and the total number of population members involved in the outbreak is constructed. We investigated the epidemic situation by an example of reports of a diseases group acute viral respiratory infections-flu in one of the districts of the Moscow region.