Trypanosoma cruzi is an African human trypanosomiasis, also known as sleeping sickness, which is a vector-borne parasitic disease. Trypanosoma brucei and Trypanosoma brucei Rhodesia are the causative agents of African trypanosomiasis or African trypanosomiasis, and the vector insects are tsetse flies. Trypanosoma gambiae is found along rivers or along forests in West and Central Africa, while Trypanosoma rhodesiae is found in shrub and vegetation zones in the savannas and lakeshores of East Africa. Africantrypanosomiasis (Africansleepingsickness) has three clinical stages, the first of which is the invasion of the skin, causing varying degrees of hardness and nodules, which evolve into trypanosomatous chancre, which occurs in about one-third of patients and is often found on the exposed skin where the tsetsefly bites. The chancre occurs in about one-third of patients and is often found on the exposed skin where the tsetsefly bites and lasts for about 3 weeks. The second period is the hemolymph period, when symptoms such as periodic fever and parasitemia occur, including lethargy, swelling of lymph nodes in the back of the neck, joint pain, headache, and red rash on the trunk, and myocarditis, and jaundice due to hemolysis and liver damage. Once the brain is invaded, the disease will enter the third stage of meningoencephalitis, where headache, insomnia, movement disorders, and behavioral disorders occur, and other symptoms include general weakness, dramatic loss of appetite, and weight loss. The pathogen is Trypanosoma brucei, which widely invades wild animals and domestic animals, among which there are three subspecies that can cause disease, namely Trypanosoma brucei Gambiense (T.b.gambiense), Trypanosoma brucei Rhodesiense (T.b.rhodesiense), Trypanosoma brucei (T.b.brucei), the former causes Trypanosoma brucei, the second causes Trypanosoma brucei, and the latter The former causes Gambian trypanosomiasis, the second causes Rhodesian trypanosomiasis, and the latter causes nagana in wildlife and domestic animals (mainly cattle), and rarely causes clinical cases, so it is not described in detail. Trypanosoma brucei is an extracellular parasitic protozoan, its subspecies morphology are very similar, so the unified description, there is a central nucleus, the posterior end of a kinetoplast, flagellum attached to the kinetoplast, along the lateral corrugated membrane of the worm to reach the front end of the worm free, trypanosomal morphology is variable, the shape is long spindle, there are elongated (20-40m long, free flagellum up to 6m) or stubby (15-25m long, 3.5m wide, free flagellum shorter than 1m). The elongated ones are mostly found in the peripheral bloodstream and are pyknotic; the stubby ones are mostly found in the tissues. Its life history is divided into two stages in tsetse flies (teeteefly), a genus of tsetse flies (Glossinae) and human body, when tsetse flies suck the blood of patients or sick animals (animals), trypanosomes with blood into the body of the fly, split and reproduce in the midgut, penetrate the intestinal wall and swim to the foregut into the esophagus, to the salivary gland to form the upper flagellar body, and finally form an infective flagellar body, this stage takes about 12 to 30 days, and makes the fly This stage takes about 12-30 days and makes the fly infectious for life (3 months). In the human body, when the infective tsetse fly bites the human body, the trypanosome enters with saliva, divides and multiplies locally, and then enters the blood stream, and the slender type is the main type at the climax of the worm blood disease. The three subspecies of trypanosomes are morphologically very similar, and in the past they were identified mainly by their pathogenicity to certain animals, biochemical characteristics (isoenzymes), reproduction in flies, clinical characteristics and endemic areas, but in recent years they have been identified by molecular biology techniques.