Computer illustration of the trypanosome Trypanosoma cruzi, which causes Chagas disease (American trypanosomiasis). It is a vector-borne parasite transmitted by the assassin bug, also known as kissing bug. These protozoa (single-celled organisms) are in the amastigote form, which lives inside the cells of tissues such as the brain, heart and liver, multiplying rapidly. Symptoms of Chagas disease include fever, enlargement of the liver, oesophagus and colon, and inflammation of the heart muscle. T. cruzi has identical morphology with the sleeping sickness parasite Trypanosoma brucei.