Parasitology Diagnostic Laboratory

Trypanosoma cruzi

The image below is of Trypanosoma cruzi. Trypanosoma cruzi is a bloodborne flagellated protozoon that causes Chagas' disease. It is a major health problem in Latin America, and is transmitted to humans when a reduviid (kissing) bug takes a blood meal and then defecates into the bite site. Trypomastigotes are detected in the blood on thin and thick smears. They are approximately 20 µm and typically C- or U-shaped. The nucleus is located in the middle of the organism, whereas the mitochondrial DNA occurs in a special organelle, the kinetoplast, located at the posterior end of the cell. A flagellum originates near the kinetoplast and follows the undulating membrane to the anterior end where it projects as a free flagellum. On Giemsa-stained smears the cytoplasm stains blueish while the nucleus and kinetoplast stain purple or red.