[Several epidemiologic features of the spread of chickenpox and herpes zoster].

Epidemiological and statistical data of herpes zoster and chickenpox by such indices as morbidity level, periodicity and month-by-month changes in the incidence of these diseases were compared. The study included 2345 herpes zoster and 11116 chickenpox cases in the course of 5 years (1972--1976). In comparison with herpes zoster, the intensity of chickenpox spread among the population was on the average 4.7 times greater. Of the total number of chickenpox cases the percentage of herpes zoster contituted 21.0. Chickenpox morbidity had marked seasonal cyclic nature with the amplitude of seasonal variations of about 8; as to herpes zoster--there was no annual or seasonal cyclicity. Thus, in the development of chickenpox and herpes zoster epidemic process there was revealed a peculiar tendency inherent to each of these infections; no common epidemiological and statistical regularities in the spread intensity, annual periodicity and seasonal cyclicity were detected.