Model of Quasi-Stationary Epidemic Kinetics

Abstract

A new theoretical model of epidemic kinetics, which takes into account the latent incubation period of the disease in the form of time lagged terms, is viewed. The model takes into account four types of population members: the uninfected (non-immune), the actively infected, the recovered and acquired immunity, and the experienced a lethal outcome. The model considers the possibility of introducing anti-epidemic measures smoothly, as well as the presence of various types of infection of the uninfected contingent. Numerical calculations of the epidemic development show that the initial exponential growth of actively infected people after the introduction of quarantine measures is replaced by a decline in the epidemic curve within two — three weeks. Then, after three months, having a permanent source of infection, the epidemic enters a quasi-stationary mode of functioning. The quasi-stationary values statistics of actively infected individuals uniquely determines the size of the infection source. Calculations of the problem with a time-varying infection source describe the «second­ wave» of a separate intensity epidemic.