Chagas' fever is caused by

Options

A. Trypanosoma cruzi
B. Trypanosoma gambiense
C. Trypanosoma brucei
D. Trypanosoma vivax.

Answer

**Step-by-Step Solution:**

1. **Identify the Disease**: Chagas' fever is also known as American trypanosomiasis. It is important to know the common name of the disease to link it to its causative agent.

2. **Determine the Causative Agent**: The question asks for the organism that causes Chagas' fever. The options provided are:
- Trypanosoma cruzi
- Trypanosoma gambiense
- Trypanosoma brucei
- Trypanosoma vivax

3. **Select the Correct Option**: Among the options, Trypanosoma cruzi is the correct answer. This organism is a protist and is specifically known to cause Chagas' disease.

4. **Understand the Transmission**: Chagas' disease is primarily transmitted by insects known as kissing bugs. This is an important aspect of the disease, as it highlights how the infection spreads.

5. **Recognize Symptoms and Effects**: The symptoms of Chagas' disease can vary and may include acute inflammatory skin changes. Over time, it can lead to serious complications, particularly affecting the heart and intestinal tract.

6. **Differentiate from Other Trypanosomes**: The other options (Trypanosoma gambiense, Trypanosoma brucei, and Trypanosoma vivax) are associated with different diseases, such as African sleeping sickness, and are not responsible for Chagas' fever.

7. **Conclusion**: Therefore, the causative agent of Chagas' fever is Trypanosoma cruzi.

**Final Answer**: Chagas' fever is caused by Trypanosoma cruzi.

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