Parasitic, flagellated protozoans of tropical regions known as trypanosomes are associated with which one of the following diseases ?

Options

A. Amoebic dysentery
B. Down syndrome
C. Syphilis
D. African sleeping sickness and chagas disease

Explanation

To solve the question regarding the parasitic, flagellated protozoans known as trypanosomes and their associated diseases, we can follow these steps:

### Step 1: Understand the Organism
- **Identify the organism**: The question mentions "trypanosomes," which are a group of parasitic protozoans belonging to the genus Trypanosoma. They are known for their flagella and are typically found in tropical regions.

### Step 2: Review the Options
- **List the options**: The options provided are:
1. Amoebic dysentery
2. Down syndrome
3. Syphilis
4. African sleeping sickness
5. Sager's disease

### Step 3: Analyze Each Option
- **Amoebic dysentery**: Caused by the Entamoeba genus, not trypanosomes. Therefore, this option is incorrect.

- **Down syndrome**: A chromosomal disorder (trisomy 21) unrelated to protozoans. This option is also incorrect.

- **Syphilis**: A sexually transmitted infection caused by the bacterium Treponema pallidum. This option is incorrect as well.

- **African sleeping sickness**: This disease is caused by the parasite Trypanosoma brucei and is transmitted by the tsetse fly. This option is correct.

- **Sager's disease**: Also known as American trypanosomiasis, caused by Trypanosoma cruzi and transmitted by the kissing bug. While this is also related to trypanosomes, the question specifically asks about the tropical region associated with trypanosomes, which aligns more closely with African sleeping sickness.

### Step 4: Conclusion
- **Identify the correct answer**: The disease associated with trypanosomes in tropical regions is **African sleeping sickness**.

### Final Answer:
African sleeping sickness

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