Data on malaria in S. Paulo State, Brazil, in the period from 1980 to 1983 are analysed. It was found that 97.0% of the cases diagnosed had their origin in other areas of the Country. Of this percentage, 93.5% came from the Amazonian region where the projects for economic development responsible for increased population displacement have been established. Some features of this population that returns to areas of transmission were selected and relating to the reason for the migration into the endemic area and the site of diagnosis in S. Paulo State. The malarial focuses which occurred during the period mentioned were analysed and correlated with the introduction of the immigrant cases or the existence of residual malaria areas. The results of this analysis contributes to the efectiveness of the control of epidemiological surveillance and it provides data for the control of endemic malaria.
Malaria; Epidemiology