Trypanosoma cruzi vs Trypanosoma brucei
How to tell Trypanosoma cruzi and Trypanosoma brucei apart when a board question makes them look alike.
Cruzi is Latin America reduviid bug Chagas with heart and GI dilation; brucei is tsetse fly African sleeping sickness with lymph nodes and CNS sleep changes.
Side by side
T. cruzi causes Chagas disease in Latin America with reduviid bug exposure, Romaña sign, acute myocarditis, chronic dilated cardiomyopathy, megaesophagus, and megacolon.
T. brucei causes African sleeping sickness after tsetse fly exposure with recurrent fevers, posterior cervical lymphadenopathy, daytime somnolence, neuropsychiatric changes, and coma.
T. cruzi enters through mucosa or broken skin after triatomine bug feces contaminate the bite site and later damages cardiac and enteric nervous tissue.
T. brucei is transmitted in tsetse fly saliva and evades immunity through antigenic variation of variant surface glycoproteins.
Trypomastigotes in blood during acute disease, amastigotes in tissue, positive serology, conduction disease, apical aneurysm, or mega-syndromes support Chagas.
Trypomastigotes in blood or CSF, Winterbottom sign, sleep disturbance, and travel or residence in sub-Saharan Africa support African trypanosomiasis.
The trap
Both are trypanosomes with bloodstream forms, but geography, vector, and chronic target organs separate them.
The repair move
For trypanosomes, pair the vector and continent before reading the organ system.
Try a free question
CoreA man from rural Bolivia develops progressive heart failure, conduction block, megaesophagus, and megacolon years after reduviid bug exposure. Which organism is most likely?
Show answer and explanation
Answer: A. Trypanosoma cruzi. Latin America exposure with chronic cardiomyopathy and GI dilation supports Chagas disease from T. cruzi.
Why the other choices are tempting
- B. T. brucei causes African sleeping sickness after tsetse fly exposure.
- C. Leishmania donovani causes visceral leishmaniasis with fever, hepatosplenomegaly, and pancytopenia.
- D. P. falciparum causes severe malaria.
- E. Toxoplasma causes CNS lesions in advanced HIV and congenital disease.
Flashcards
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What vector transmits Trypanosoma cruzi?
The reduviid or triatomine bug transmits T. cruzi through fecal contamination of the bite site.
What chronic organs does Chagas disease damage?
Chagas disease chronically damages the heart and enteric nervous system, causing cardiomyopathy, megaesophagus, and megacolon.
Quick answers
What is the fastest way to tell Trypanosoma cruzi from Trypanosoma brucei?
Cruzi is Latin America reduviid bug Chagas with heart and GI dilation; brucei is tsetse fly African sleeping sickness with lymph nodes and CNS sleep changes.
What is the key clue for Trypanosoma cruzi?
T. cruzi causes Chagas disease in Latin America with reduviid bug exposure, Romaña sign, acute myocarditis, chronic dilated cardiomyopathy, megaesophagus, and megacolon.
What is the key clue for Trypanosoma brucei?
T. brucei causes African sleeping sickness after tsetse fly exposure with recurrent fevers, posterior cervical lymphadenopathy, daytime somnolence, neuropsychiatric changes, and coma.
What is the common trap with Trypanosoma cruzi vs Trypanosoma brucei?
Both are trypanosomes with bloodstream forms, but geography, vector, and chronic target organs separate them.