the peculiar infestation of the rural houses with a large hematophagous insect of the genus Triatoma, a kind of "assassin bug" or "kissing" bug (barbeiro or "barber" in Portuguese, so-called because it sucked the blood at night by biting the faces of its victims). He discovered that the intestines of these insects harbored flagellate protozoans, a new species of the genus Trypanosoma, and was able to prove experimentally that it could be transmitted to marmoset monkeys that were bitten by the infected bug. Chagas named this new parasite Trypanosoma cruzi in honor of Oswaldo Cruz and later that year as Schizotrypanum cruzi and then once again as Trypanosoma cruzi. Chagas suspected that the parasite could cause human disease, due to the prevalence of the insect vector in human households and its habit of biting people, so he took blood samples and, on April 23, 1909, discovered for the first time the same Trypanosoma parasite in the blood of a 3-year-old girl. He also observed parasitic inclusions in the brain and myocardium that would explain some of the clinical manifestations in diseased people and closed the proposed lifecycle of the parasite by suggesting that the armadillo could be its natural reservoir. To complete his work on the pathology of the new disease, Chagas described 27 cases of the acute form of the disease and performed more than 100 autopsies on patients who exhibited the chronic form. His description of the new disease was to become a classic in medicine, and brought him domestic and international distinction. He was elected to the National Academy of Medicine and received the prestigious Schaudinn Prize for the best work in protozoology and tropical medicine, on June 22, 1912. The contenders included Paul Ehrlich (1854–1915), Emile Roux (1853–1933), Ilya Mechnikov (1845–1916), Charles Laveran (1845–1922), Charles Nicolle (1866–1936), and Sir William Boog Leishman (1865–1926), several of whom had already received or would receive the Nobel Prize for Medicine. Chagas also persuaded Argentine physician Salvador Mazza to research the epidemic, leading to the latter's confirmation of the existence of Trypanosoma cruzi in Argentina in 1927, and eventually to government action. Chagas was also the first to discover the parasitic fungal genus Pneumocystis in the lungs of his experimentally trypanosome-infected animals. At the time, he did not recognize it as a separate organism, so he described his genus Schizotrypanum to accommodate both lifecycles that he illustrated beautifully. However, his