Carlos Chagas

Carlos Justiniano Ribeiro Chagas, or Carlos Chagas (, ; 1879–1934), was a Brazilian sanitary physician, scientist and bacteriologist who worked as a clinician and researcher. He discovered Chagas disease, also called American trypanosomiasis in 1909, while working at the Oswaldo Cruz Institute in Rio de Janeiro.

Chagas’ work is unique in the history of medicine, because he was the only researcher so far to describe completely a new infectious disease: its pathogen, vector (Triatominae), host, clinical manifestations and epidemiology. Chagas was also the first to discover and illustrate the parasitic fungal genus Pneumocystis, later infamously to be linked to PCP (Pneumocystis pneumonia in AIDS victims).