[American human trypanosomiasis 90 years after its discovery by Carlos Chagas. I. Epidemiology and control].

It was in 1909 that Carlos Chagas described the disease which now bears his name. During the ensuing 90 years, our knowledge of this apparently whimsical, protozoan disease has grown enormously but many points remain unclear. Epidemiologically speaking, current knowledge is poor about the mechanisms and markers of variability of Trypanosoma cruzi, mechanisms allowing the organism to survive in the host, and susceptibility of infected individuals to disabling or fatal late complications. With regard to vector control, it is increasingly obvious that success will be more difficult than previously thought due to the likelihood that, as domestic species are exterminated, they will be replaced by semi-domesticated or wild species. Two other factors that have significantly changed the conventional epidemiological profile of Chagas'disease on the subcontinent over the past 50 years are human intervention in the environment and population migration from rural to urban zones. Despite the breakthroughs achieved in the last decade. Chagas'disease, with its multiple modes of transmission (vector-borne, congenital, and transfusional to name but the most important), diverse reservoir involving over 175 species, and potential for course of the disease in man, will remain a major health problem in Latin America countries for many years to come.