Chagas was also the first to discover the parasitic fungal genus Pneumocystis in the lungs of his experimentally trypanosome-infected animals. At the time, he did not recognize it as a separate organism, so he described his genus Schizotrypanum to accommodate both lifecycles that he illustrated beautifully. However, his discovery led others to further investigate and describe Pneumocystis as a distinct genus, which is now known to be a fungus. Chagas followed the literature closely and quickly confirmed the distinction, whereupon he again adopted the name Trypanosoma cruzi that he had originally coined. Pneumocystis is now linked to another disease, pneumocystis pneumonia, caused by one species (P. jirovecii), but the original Pneumocystis species seen by Chagas in guinea pigs has not yet been named as a separate species.
