This leprosarium was founded by the National Department of Public Health, and opened by Souza Araujo on 24 June 1924, with 354 patients. There was also a creche with twenty beds for children born in the institution.
(Araujo, H C S. 'The Leprosy Problem in Brazil'. The American Journal of Tropical Medicine, 1925:5 (3) 222)

The establishment in which the leprosarium was later installed was originally named Instituto S. Antonio do Prata. It was inaugurated in 1908, having been founded in 1900, by the Capuchin order, for the education of indigenous children from the region of the Guamá river.
In 1921, the establishment became a Correctional Colony. On 27 May 1922, Souza Araujo paid a visit to the Colony to verify whether it would be suitable as a leprosarium. This plan was approved and the leprosarium was founded 24 June 1923 and immediately received 22 patients. Souza Araujo was the Chefe do Serviço de Prophylaxia Rural (Head of the Rural Prophylaxis Service) at the time, so was corresponding in connection with the establishment of the leprosarium. The internal regulations were approved by the Chief Inspector of the Prophylaxis of Leprosy. Initially, the inauguration was planned for 1 January 1924, but this was not possible due to difficulties in transporting credit and materials; Souza Araujo, as Head of the Rural Sanitary Service of Pará, opened the institution (the first federal leprosarium of Brazil) on 24 June 1924, in the presence of the State Governor, Dr Souza Castro.
On 22 November 1924, Dr João Auzier Bentes, who had replaced Souza Araujo as Head of the Rural Sanitary Service earlier in the year, paid his first visit to Lazarópolis do Prata. His impression was that the location was magnificent, the installations excellent, the management exemplary and humanistic, and the appearance of patients relatively content. He praised the director, Dr Amaro Damasceno Junior, who was replaced in 1926 by Dr Bernardo L Rutowitcz.
(Araujo, H C S. 'Contribuição á epidemiologia e prophylaxia da lepra no norte do Brasil'. Memórias do Instituto Oswaldo Cruz, 1933:27, 196-204)