Hemoflagellates (trypanosomes and Leishmania) !
- Parasites
Flagellated protozoa with a kinetoplast that live in blood or inside cells, spread by insects: kissing bugs, sand flies and the tsetse fly.
Updated 2026-11-01
What they are
These are the trypanosomatids that infect humans: Trypanosoma cruzi (Chagas disease), Trypanosoma brucei (African sleeping sickness) and the Leishmania species. Each changes form between the insect vector and the human host. In Colombia, Chagas disease and leishmaniasis are notifiable public-health events.
What they share
- A single flagellum and a kinetoplast (a dense mass of mitochondrial DNA) visible on Giemsa stain.
- Stage-specific forms: trypomastigote (flagellum with undulating membrane), epimastigote, promastigote and amastigote (no free flagellum, intracellular).
- Vector-borne: triatomine bugs (T. cruzi), Lutzomyia/Phlebotomus sand flies (Leishmania), Glossina flies (T. brucei).
- T. cruzi and Leishmania amastigotes look alike under the microscope; tissue and context tell them apart.
Microorganisms in this group
- Trypanosoma cruziThe parasite of Chagas disease. It spreads through the feces of kissing bugs («pito» in Colombia), contaminated food and from mother to baby.Exam priority: high
- Leishmania (Viannia) panamensis, L. braziliensis and L. guyanensisParasites spread by sand flies in forested areas that cause chronic skin ulcers; some species later damage the nose and mouth.Exam priority: high
- Leishmania infantumA Leishmania that invades the liver, spleen and bone marrow. It causes fever, a huge spleen and anemia, mostly in young children; usually fatal untreated.Exam priority: high
- Trypanosoma brucei gambiense and T. b. rhodesienseAn African parasite spread by the tsetse fly. It first causes fever and swollen glands, then invades the brain and disrupts sleep.Exam priority: medium
Test yourself
Think of the answer, then tap the question to see it.
Which Leishmania stage is found inside human macrophages?
The amastigote: small, oval, with a nucleus and a kinetoplast and no free flagellum.
Which trypanosome multiplies extracellularly in blood and CSF?
Trypanosoma brucei. T. cruzi only divides inside cells, as an amastigote.
Which vector transmits each hemoflagellate?
T. cruzi: triatomine (kissing) bugs; Leishmania: sand flies (Lutzomyia in the Americas); T. brucei: the tsetse fly (Glossina).
Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: CDC - DPDx - American Trypanosomiasis (CDC, 2024); CDC - DPDx - Leishmaniasis (CDC, 2024); CDC - DPDx - Trypanosomiasis, African (CDC, 2024).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.