During the earliest years of the Federal Serum Therapy Institute, the prime target of research by Cruz’s team were the fights against smallpox, yellow fever, and the bubonic plague, diseases that accounted for the bulk of the initiatives by the General Directorate of Public Health in the federal capital.
The fact that Cruz was head of both the institute and the General Directorate in 1903 made it easier to expand and diversify the investigations conducted by scientists at the Federal Serum Therapy Institute. Diseases like malaria, tuberculosis, filariasis, and beriberi became part of the institute’s regular work. After Alcides Godoy discovered the vaccine against blackleg in 1907, veterinary research also gained new momentum; the same can be said of medical entomology, a field whose studies were proving of great value in the development of tropical medicine.
The transformation of the Federal Serum Therapy Institute into the Oswaldo Cruz Institute in 1908 solidified this process. With the arrival of new researchers and a stronger policy of scientific exchange, biomedical research reached new heights. That very year, the team was strengthened with the hiring of Adolfo Lutz. Other new additions were Gaspar Viana, who took over the area of pathological anatomy, and José Gomes de Faria, who in 1910 was to announce the discovery of Ancylostoma braziliense, a hookworm that is a parasite of dogs and cats. The 1909 creation of the journal Memórias do Instituto Oswaldo Cruz was another landmark during this period.
Cruz fostered international exchange by sending Brazilian researchers abroad on specialized internships in the United States and Europe and by inviting eminent scientists to work at the institute. The recruitment of German scientists like Stanislas Von Prowazek and Gustav Giemsa, from the Institute for Maritime and Tropical Diseases (now the Bernhard Nocht Institute for Tropical Medicine), and Max Hartmann, of the Institute for Infectious Diseases in Berlin (now the Robert Koch Institute), put the institute in contact with the latest knowledge in disease transmission by insects and afforded Brazilian researchers the opportunity to keep abreast of recent discoveries on the role of protozoans in human illnesses, like African trypanosomiasis (sleeping sickness).
Enriched by these studies, tropical medicine became a permanent field of research. It was also thanks to this work that Carlos Chagas achieved what is recognized as the institute’s greatest contribution to our understanding of infectious disease.
In mid-1907, Cruz assigned Carlos Chagas to go to Lassance, in northern Minas Gerais, in order to bring a malaria epidemic under control. In parallel with his work to combat the disease, Chagas spent time collecting specimens of local fauna and examining them in a small laboratory installed for him inside a train car. It was during the course of one of these investigations that he identified a protozoan in the form of a trypanosome inside the gut of a bloodsucking insect known as a barbeiro (barber bug), or kissing bug. He was unable to make any further progress with this research where he was, so he sent some specimens of the insect to Cruz. After placing the kissing bugs in contact with laboratory monkeys, Cruz observed that some of the animals fell ill, and he found protozoans in their blood.
Informed of the results of the experiment, Carlos Chagas returned to the institute, where he concluded that the protozoan Cruz had found was a new species of trypanosome, which he named Trypanosoma cruzi in honor of his mentor. Once back in Lassance, Chagas did blood tests on the local residents. At last, on April 14, 1909, he detected the presence of T. cruzi in the blood of a feverish child. He had discovered a new human sickness.
One week later, Cruz announced his disciple’s extraordinary accomplishment to the members of the National Academy of Medicine. At the suggestion of Miguel Couto, the new trypanosomiasis began to go by the name of “Chagas disease”.
The fusion of tropical medicine and microbiology gave birth to a new and original type of scientific organization, one that conjoined the interests of knowledge production with the demands of public health. This model characterized the work of the Oswaldo Cruz Institute throughout the twentieth century and set it apart from other public research institutions in Brazil.