Evolution of the clinical and epidemiological knowledge about Chagas disease 90 years after its discovery

Three different periods may be considered in the evolution of knowledge abo ut the clinical and epidemiological aspects of Chagas disease since its dis covery: (a) early period concerning the studies carried out by Car los Chag as in Lassance with the collaboration of other investigators of the Manguin hos School. At that time the disease was described and the parasite, transm itters and reservoirs were studied The coexistence of endemic goiter in the same region generated some confusion about the clinical forms of the disea se; (b) second period involving uncertainty and the description of isolated cases, which lasted until the 1940 decade. Many acute cases were described during this period and the disease was recognized in many Latin American c ountries. Particularly, important were the studies of the Argentine Mission of Regional Pathology Studies, which culminated with the description of th e Romana sign in the 1930 decade, facilitating the diagnosis of the early p hase of the disease. However, the chronic phase, which was the most importa nt, continued to be difficult to recognize; (c) period of consolidation of knowledge and recognition of the importance of Chagas disease. Studies cond ucted by Laranja, Dias and Nobrega in Bambui updated the description of Cha gas heart disease made by Carlos Chagas and Eurico Villela. From then on, t he disease was more easily recognized, especially with the emphasis on the use of a serologic diagnosis; (d) period of enlargement of knowledges on th e disease. The studies on denervation conducted in Ribeirao Preto by Fritz Koberle starting in the 1950 decade led to a better understanding of the re lations between Chagas disease and megaesophagus and other visceral megas d etected in endemic areas.