Cardiac fibrosis in mice chronically infected with T. cruzi after oral transmission. (a) Representative myocardial sections stained with picro-sirius red, magnification 400X and 100X , scale bar = 100 µm. (b) Quantification of collagen content (% red area in stained sections) as a marker of cardiac fibrosis severity. Data are the means ± SEM, pooled from three experiments. Not infected n = 12, MT oral n = 5, MT i.p. n = 12, BT i.p. n = 8. Asterisks indicate p-values for comparisons with the not infected control group in a one-way ANOVA test (*p < 0.05; ***p < 0.001).