One of the best-known stories in the history of parasitology is that of Carlos Chagas, a young Brazilian doctor, who, sent to investigate a debilitating disease in a remote area, discovered flagellates in the intestine of blood-sucking bugs, showed that they could be transmitted to humans and caused the disease that now bears his name. This is a nice story but according to François Delaporte in this book, a translation of the original La maladie de Chagas published in 1999, this story is not as straightforward as it seems. In fact, Delaporte suggests that historians have taken too much of what Chagas himself had to say at face value and that he did not discover the parasite involved, Trypanosoma cruzi, nor its life cycle and did not discover American trypanosomiasis. The background to this story is the establishment of the Manguinhos Institute in Rio de Janeiro and the genius behind it, Oswaldo Cruz, whose tireless efforts brought this world-class institute, now the Fundação Oswaldo Cruz, into being. In 1909 Cruz, then the Director, recruited Chagas, mainly because of his expertise with malaria, and sent him to a remote area, Minas Gerais, where by chance he discovered flagellated crithidia in the guts of kissing bugs. This was not at all unusual because numerous crithidia had been found in the guts of insects. Chagas, however, asked himself if these flagellates could be the developmental stages of Trypanosoma minasense, a common but harmless parasite of monkeys. Chagas was unable to find the clean monkeys he needed for his experiments and sent some infected bugs to the Manguinos Institute where Cruz infected clean monkeys and found that they developed a mild infection characteristic of T. minasense but also a very virulent trypanosome infection which actually turned out to be Trypanosoma cruzi. Chagas then rewrote the history implying, but not necessarily stating, that it was he and not Cruz who had made the discovery. Now on to the second myth, the discovery of the parasite's life cycle. Based on his knowledge of malaria, Chagas described sexual stages in the life cycle and postulated that after gametogeny the infective stages made their way to the salivary glands of the bug and were injected when the bug fed on a human or animal host. It was many years later that Emile Brumpt was to show that that the infective stages were passed out in the faeces and rubbed into the site of the bite. Chagas was also at sea when he tried to explain the disease. Chagas began to look for symptoms associated with African trypansomiasis so he focused on thyroid hypotrophy and reached the conclusion that the symptoms of the disease involved the nervous system but was neither thyroiditis nor African sleeping sickness but something in between. Although incorrect this fitted very well with the then current theory that some endocrine diseases were caused by toxins released by microorganisms.

If Delaporte is correct then Chagas did not discover the causative organisms of American trypanosomiasis, did not work out the life cycle in the bug and did not discover the disease. So why is he so revered? Delaporte thinks that this is because Chagas was an expert at reformulating the past by rewriting history. Over the decades following the discovery of T. cruzi, several well-known individuals began to question Chagas's interpretation of events but their impact was lessened because they had real or imaginary axes to grind. The most vehement critic was Figueriedo Vasconcellos who, in 1919, gave a critical account of Chagas's discoveries and suggested that Chagas had misappropriated the work of his colleagues but lost his argument because he unjustifiably questioned Chagas's motives. It was not until 1922 that Chagas acknowledged Cruz's real contribution and the furore died down. In 1935, Cecilio Romana, who had worked at the Oswaldo Cruz Institute, put the final piece of the jigsaw in place when he reported that the oedema in the eyelid was due to an inflammatory response at the point where the parasites were introduced into the body. Facial oedema was also to become the basis of a simple diagnostic test for Chagas disease. Chagas was present at Romana's lecture and must have wondered how he had missed such an obvious lesion.

Chagas's career was not affected by perceived scandals. He was appointed head of the Institute in 1917, in 1919 he became Director General of Public Health and was a candidate for the Nobel prize for medicine in 1920. Perhaps Chagas did not do everything that was attributed to him but his contributions to our understanding of Chagas disease should not be underestimated.