 the following year with a thesis on the hematology of malaria, working at the new medical research institute created by noted physician, and later friend and colleague, Oswaldo Cruz (1872–1917).After a brief stint as a medical practitioner in the hinterlands, Chagas accepted a position in the port authority of Santos, São Paulo, with the mission of fighting the malaria epidemic, which was affecting its workers.There, he introduced an innovation, which consisted in using pyrethrum, an insecticide, to treat households, with surprising success.