In 1906, shortly before Alcides Godoy announced the discovery of the vaccine against blackleg, the government of Minas Gerais suggested to Oswaldo Cruz that a branch of the institute be established in Belo Horizonte, the young capital of the state. At the time, farmers there were facing severe losses, with the disease slaughtering 40% to 80% of their calves. Inaugurated in August of that year, the institute’s first branch was headed by Ezequiel Dias, one of Cruz’s longest-running collaborators.
In addition to controlling the epidemics then assailing the state’s animals and to making sera and vaccines, the facility began conducting research on a number of other diseases. Ezequiel Dias himself made valuable contributions to the body of knowledge on diseases like leukemia, paracoccidioidomycosis (a fungal infection endemic to Brazil), and Corynebacterium pyogenes infection, which attacks calves. Another important line of research conducted by scientists at the branch was on Chagas disease, with particular attention to the geographic distribution of the kissing bug and its rate of infection by Trypanosoma cruzi.
The year that Ezequiel Dias inaugurated the facility in Belo Horizonte, Cruz sent the scientist Antônio Cardoso Fontes to fight the bubonic plague in São Luís, in the far northern state of Maranhão, where he was also to help set up state health services. One outgrowth of this work would be another branch of the institute, established there in 1919, after the death of Cruz.
In 1914, with Cruz still director, Arthur Neiva established yet another branch, this one in far southern Brazil, in Pelotas, Rio Grande do Sul. The facility was, however, short-lived.
Following the victory of the Revolution of 1930, the government cut funding to the Oswaldo Cruz Institute and its branches, culminating in the closing of the Maranhão facility the very next year. The branch in Belo Horizonte—renamed the Ezequiel Dias Institute in 1922—remained open but in 1936 was transferred to the government of Minas Gerais. That same year, the government of Pará opened the Northern Institute of Experimental Pathology (IPEN), which operated as an associate institute.
In December 1937, Getúlio Vargas signed a decree prohibiting the Oswaldo Cruz Institute from maintaining branches anywhere in Brazil.