In this study estimates are made of the true incidence, mortality and case-fatality ratio of measles in the Municipio do Rio de Janeiro, Brazil, for the prevaccination period 1969-1972 and the post vaccination period 1979-1982. The estimates are obtained by applying some correction factors to the reported number of cases and deaths in each of the two periods. The number of cases is estimated by considering the population dynamics and the dynamics of measles transmission in the population. The number of deaths is estimated by taking into account the underreporting of deaths, from information obtained by the Inter-American Investigation of Infant Mortality. A detailed presentation and discussion is made of the methodology used throughout, which will possibly be of interest to the health services in the assessment of intervention measures. Finally, on the basis of the corrected indicators obtained, the epidemiological situation of measles in Rio de Janeiro is discussed.
