Incidence of meningococcal infection in the RSFSR

: The authors present characteristics of meningococcus infection epidemic process in case of sporadic cases and under epidemic conditions (1965--1976). A scheme of epidemiological analysis suggested by the authors permitted to differentiate and to record the incidence of various clinical forms of meningococcus infection, to present data on the age, seasonal characteristics, focality, etc. Comparison of intensive morbidity indices for 10 years, both at the individual administration territories and in the Republic as a whole demonstrated morbidity level of 1.5--2.0 to be one of prognostic signs of the beginning epidemic. The main features differentiating the sporadic and epidemic morbidity periods were revealed. The presence of group diseases, a greater percentage of children among those who fell ill, and marked signs of seasonality and territorial difference characterized the period of rise caused by meningococcus of serological group A.