Challenge of Chronic T. cruzi- infected mice with trypomastigotes activates the immune system and reduces sub-patent parasitemia levels - Marinho, Claudio Romero Farias; Bastos, K. R. B.; Lima, Maria Regina D'Império; Sardinha, L. R.; Grisotto, M. G.; Alvarez, José Maria (Meeting of the Brazilian Society of Immunology, 2003)