Study of a historical series survey showed the coefficients running into high numbers indicating the positiveness of the Machado-Guerreiro reaction among army draftees called to service in the city of S. Paulo. Attention is called to the fact taht these figures are higher that those found among army draftees called to service in the hinterland where, paradoxally, the endemic areas exist. As the existence of Chagas transmission in the city of S. Paulo has not been reported, its occurrence can be ascribed to the coming of migrants infected in the areas they come from. Study of the place of origin of young draftees brought evidence which sustains this hypothesis. These data emphasize the presence of social factors in determining the occurrence and distribution of the disease in the community.
Tripanosomiasis, South American; Socioeconomic factors
