PetriKey

Parasite

Trypanosoma brucei

Tsetse-borne cause of African sleeping sickness

trih-PAN-oh-SOH-muh BROO-see-eye

protozoahemoflagellatetsetsecnszoonosis

High-yield clue

Blood/CSF trypomastigotes with a single flagellum and undulating membrane, plus posterior cervical lymph nodes (Winterbottom's sign), are the key study clues.

Overview

A hemoflagellate protozoan complex (T. b. gambiense and T. b. rhodesiense) transmitted by the tsetse fly that causes human African trypanosomiasis. It matters as the classic vector-borne parasite with central nervous system involvement.

Classification

  • Protozoa
  • Kinetoplastid hemoflagellate
  • Extracellular
  • Undulating membrane morphology

Lab & identification clues

  • Giemsa blood/CSF smear trypomastigotes
  • Kinetoplast + undulating membrane vocabulary
  • Motile flagellate on wet mount
  • Antigenic variation (VSG) surface-coat concept

Associations

  • Tsetse fly (Glossina) vector
  • West/Central Africa (gambiense) vs East Africa (rhodesiense)
  • Winterbottom's sign lymphadenopathy vocabulary
  • Sleeping-sickness CNS-stage study framing

Commonly confused with

  • Trypanosoma cruzi
  • Leishmania species

Your notes

Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.

OpenStax: Microbiology 2e organism classification foundationssourceNCBI Bookshelf: Medical Microbiology organism chapterssourceCDC: CDC disease and public-health topic pagessource