In this work there is shown the value of the immunological screening in the organization and implementation of the epidemiological surveillance of natural focal infections. The application of this method with regard to this group of infections, allows to detect the frequency and the level of so-called "pro-epidemising" of the population, also helps with the identification of the mild, subclinical, latent forms of disease not detected by the clinical method of the diagnosis. The obtained results clearly demonstrate extensive nosoareals of natural focal infections in the territory of the subject among the population with different levels of seropositivity, and thus indicate to the needfor the implementation of the immunological screening in the future as an relevant diagnostic tool in the formulation of the diagnosis in epidemiological surveillance system.