A study of under-reporting of meningitis in five communities in the State of S. Paulo (Brazil), during an outbreak of meningococcal meningitis was undertaken. The number of "cases" (not notified during life) achieved through the examination of death records was used as an indirect measure of under-reporting. There was a variation in under-reporting during the epidemic period: it decreased from 37.6% in 1971 to 2.1% in 1975, following a negative exponential pathway, at a measurable rate. The application of the methodology presented in this paper would provide a more accurate knowledge of the incidence of the disease allowing a better interpretation of the trends of the epidemic in order to evaluate the effectiveness of policies adopted to control it.
Meningococcal meningitis; Epidemic under-reporting