Chagas, Carlos Ribeiro Justiniano (1879–1934), Brazilian physician. Early in his career Chagas undertook a malaria control campaign that used pyrethrum to disinfect households and that proved to be the first successful campaign against malaria in the history of Brazil. During 1909 and 1910 Chagas discovered and described the disease named after him. He discovered that it is caused by a species of trypanosome transmitted by bloodsucking reduviid bugs and that it is manifested by fever and edema and later by cardiac disturbances. He also described its epidemiology and some of its pathogenic hosts.