TCN2 and Chagas disease: Whereas CL Brener (TcVI), together with the TcII and TcV strains, is the predominant cause of Chagas disease in the Southern Cone of Latin America (1, 2), Sylvio X10/1 and Dm28c belong to TcI, a group related to the sylvatic cycle that is also associated with Chagas disease in the Brazilian Amazon, Venezuela, Colombia, and Central America (3).