Policies to combat Chagas disease presents a considerable degree of negligence and is classified at level III by TDR, where the focus of research is based on the improvement and wider dissemination of existing tools and strategies for combating them. The PACT is based on topical or systemic administration of a nontoxic dye sensitive to light, followed by low dose irradiation with visible light of wavelength appropriate. In the presence of oxygen found in the cells, the photosensitizer (FS) enabled may react with molecules in its vicinity by electron transfer or hydrogen, leading to production of free radicals (type I reaction) or by energy transfer to oxygen (type II reaction), leading to production of singlet oxygen. Both paths can lead to cell death and the destruction of diseased tissue. In this work, we verify the effectiveness of PACT associated with a semiconductor laser InGaAlP, a wavelength (λ) equal to 660 nm±10 nm, 30 mW optical power, emitting red light in the visible spectrum, with a dose of 4 J/cm2 in continuous mode, using methylene blue in five differents concentrations on the infective trypomastigote forms of Trypanosoma cruzi. To determine the viability of the parasites, one sample from each treatment group at each concentration was removed and analyzed in a hemocytometer, observing the decrease in the number of live parasites for the solution without treatment. The results demonstrated significant percentage of parasite lysis (up to 86% lethality), what can not be observed in the groups treated with laser or with the FS.

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