[Analysis of the Mechanism of a Three-Wave Epidemic Influenza A Virus Cvcle].

A three-wave epidemic cycle caused by a new serotype agent is simulated. The mechanism of stepwise recession in a stratum of the susceptible persons is examined. A group of asymptomatic infected individuals as well as an antigen activity index, which regulates the intensity of input streams into the groups of infected patients, are introduced into the model. Morbidity rate is additionally regulated by the virulence. The model is identified according to the observations of the three-wave passage of Hong-Kong serotype (H3N2). On the basis of the simulation results it is shown that a leading role in upgrading the virulence capacity of the agent and in replenishment of the morbid group is assigned to the asymptomatic infected individuals.