[Meningococcal disease in São Paulo, Brazil, in the 20th century: epidemiological characteristics].

This study analyzes the epidemiological behavior of meningococcal disease in the city of São Paulo, Brazil, over the course of the 20th century. Applying data from patient records, death certificates, and epidemiological surveillance, the authors describe trends in the disease throughout the century, seasonal variations, and incidence distribution by area, age, and gender. The temporal trends show constant incidence during endemic periods, interrupted by epidemic events. Four epidemic events during the last century occurred in circumstances of serious social disturbances and were caused by serogroups A (the first two), A and C, and B and C, respectively. Seasonal variations involved aggravation during autumn and winter throughout the entire century. Geographic distribution followed the displacement of the poor population in the urban territory. Age and gender distribution remained unaltered during all the endemic periods, showing an increased risk associated with younger age. The epidemic periods (except for the last) showed major alterations in age and gender distribution, with an increased risk among young people and youth adults and occurrence in all age brackets.