Benznidazole and Chagas disease: can an old drug be the answer to an old problem?

Background: Chagas disease is a significant public health problem in the Americas, despite efforts to decrease the number of new cases since 1990. Etiologic treatment of the disease's chronic phase is still controversial. Objective: We reviewed the strongest studies to evaluate the drugs used in the acute and chronic disease phases, with emphasis on benznidazole. Methods: A Medline search using the keywords ‘Chagas disease’ and ‘treatment,’ with no date limitations, was performed. Results: Study methods in completed trials varied greatly, with none being a randomized, double-blind, placebo-controlled study. The only trial using these methods is still ongoing. The treatment in acute phase is the major indication, but during chronic phase doubts still remain. Conclusion: Only patients in the acute phase of Chagas disease (whatever their age; including children and adolescents) who are treated have good outcomes, although the criteria defining ‘cure’ remain controversial.