Summary
In april, 1977, an outbreak of falciparum malaria occured in the Sanomã and Mayongong indian tribes in Brazil (Roraima) bordering Venezuela. Two hundred and sixty-eight indians were examined for malaria and 91 cases were found. Only one vector species, Anopheles darlingi was found, whose activities averaged 64 bites per man per night. Three cases of falciparum were resistant to chloroquine but responded favorably to Fansidar (sulphadoxina and pyrimethamine). There were distinct differences between tribes based on the proximity to the vector population. These differences are presented by age and sex. One group of Sanomã in an effort to escape malaria moved to a remote area, which interestingly was free of man-biting mosquitoes.