This book has been "considered by some authors to be the first reference to the chagasic megaesophagus and megacolon that appeared in history. In descriptions considered to refer megaesophagus, although dysphagia, the major symptom of this disease, is not recognized, typical manifestations of a irritating, inflammatory or ulcerative condition are identified, not affecting the esophagus but the stomach. In the description considered to refer to megacolon, the signs and symptoms suggest the diagnostic possibility of hemorrhoids and of the "achaque do bicho" itself, and do not recall the clinical picture of the chagasic megacolon in an absolute manner. On this basis, there is no reason to maintain the book "Noticias do que he o achaque do bicho" within the history of the digestive form of Chagas' disease" (https://www.ncbi.nlm.nih.gov/pubmed/9201322).

"The author started his life as a shopboy and became a prosperous merchant. It seems that he earned considerable sums by buying very cheap slaves who were sick with the "bicho", curing them and selling them at a good profit. He was not a physician,  and in the preface he states that he published his book only out of charity. This book is one of the three most important and rarest works on medicine written in Brazil." (Moraes). Digital facsimile from the John Carter Brown Library, Internet Archive, at this link.